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TRANSCRIPT
St. Petersburg State University
12th International Conference and School
“PROBLEMS OF GEOCOSMOS”
Book of Abstracts
St. Petersburg, Petrodvorets, October 8–12, 2018
St. Petersburg
2018
2
Chairman:
Prof. V.S. Semenov
St. Petersburg State University, Russia
Vice-chairman:
Dr. S.V. Apatenkov
St. Petersburg State University, Russia
Organizing Committee:
Dr. N.Yu. Bobrov,. St. Petersburg State University, Russia
Dr. V.V. Karpinsky, St. Petersburg State University, Russia
Dr. M.V. Kubyshkina, St. Petersburg State University, Russia
Dr. T.A. Kudryavtseva, St. Petersburg State University, Russia
Dr. E.L. Lyskova, St. Petersburg State University, Russia
N.P. Legenkova, St. Petersburg State University, Russia
Dr. I.A. Mironova, St. Petersburg State University, Russia
M.V. Riabova, St. Petersburg State University, Russia
R.V. Smirnova, St. Petersburg State University, Russia
Program Committee:
Dr. A.V. Divin, St. Petersburg State University, Russia
Prof. I.N. Eltsov, Institute of Petroleum Geology and Geophysics SB RAS, Russia
Prof. N.V. Erkaev, Institute of Computational Modelling SB RAS, Russia
Prof. B.M. Kashtan, St. Petersburg State University, Russia
Dr. P.V. Kharitonskii, St. Petersburg State University, Russia
Prof. Yu.A. Kopytenko, SPbF IZMIRAN, Russia
Dr. A.A. Kosterov, St. Petersburg State University, Russia
Dr. V.E. Pavlov, Schmidt Institute of Physics of the Earth, RAS, Russia
Prof. V.N. Troyan, St. Petersburg State University, Russia
Prof. V.A. Sergeev, St. Petersburg State University, Russia
Dr. E.S. Sergienko, St. Petersburg State University, Russia
Dr. N.A. Tsyganenko, St. Petersburg State University, Russia
Prof. T.B. Yanovskaya, St. Petersburg State University, Russia
Dr. N.V. Zolotova, St. Petersburg State University, Russia
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CONTENTS
SECTION EG. EXPLORATION AND ENVIRONMENTAL GEOPHYSICS ....................................26
Conveners - Dr. N.Y.Bobrov, Dr. A.K.Saraev ......................................................................................................... 26
STRUCTURE OF THE NORTHERN PART OF SOUTH-ONEGA SYNCLINE BASING ON AMT,
GRAVITY AND MAGNETOMETRY DATA .......................................................................................26
K.Antashchuk1, K.Stepanov
2, A.Saraev
1................................................................................................................ 26
BASIC 3-D GEOELECTRIC MODEL OF THE LITHOSPHERE OF BELARUS ............................27
Astapenko V.N., Dubanevich M.A. ...................................................................................................................... 27
TRANSIENT ELECTROMAGNETIC SOUNDINGS OF MAGNETICALLY VISCOUS ROCKS IN
THE ZHAMANSHIN IMPACT CRATER ............................................................................................27
Bobrov N.Yu. ........................................................................................................................................................ 27
RECENT RESEARCH OF GEOPHYSICAL PARAMETERS OF THE LITHOSPHERE
PLATFORM REGIONS ..........................................................................................................................28
Burakhovych T.K, Kushnir A.N., Tsvetkova T.A. .................................................................................................... 28
RESEARCHING OF PHYSICO-CHEMICAL PROPERTIES OF RESEVOIR FLUIDS BY NMR-
RELAXOMETRY METHOD ..................................................................................................................29
E.S.Chernova1, M.Y.Shumskayte
2 ......................................................................................................................... 29
NEW MAGNETOTELLURIC STUDY OF THE DEEP STRUCTURE OF THE SOUTH-
WESTERN CRIMEA ...............................................................................................................................30
Desyatov D.O.1, Pushkarev P.Yu.
1, Rokityansky I.I.
2, Stafeev A.N.
1, Yakovlev A.G.
1,3 ............................................ 30
THE FEATURES OF DEAD BAND AMT SIGNAL IN CHUKOTKA REGION ..............................30
THE WAY OF THE HOST MEDIUM INFLUENCE CORRECTION IN THE EXPRESS-
INTERPRETATION OF 2D MAGNETOVARIATIONAL ANOMALIES .......................................31
E.Ermolin1, O.Ingerov
2 ......................................................................................................................................... 31
DISTORTION OF LOCAL MAGNETOVARIATIONAL ANOMALIES BY EFFECT OF
REGIONAL STRUCTURES .................................................................................................................31
E.Ermolin1, O.Ingerov
2 ......................................................................................................................................... 31
4
ANALYSIS OF THE EFFECT OF ENVIRONMENTAL FACTORS ON THE DISEASE
INCIDENCE OF PETROZAVODSK RESIDENTS, BASED ON EMERGENCY CALL DATA ......32
Gerasimova А.А., Belashev B.Z., Krutskikh N.V. ................................................................................................... 32
THE EXPERIENCE OF LOW-ALTITUDE MAGNETIC SURVEY USING UNMANNED
COMPLEX GEOSCAN 401 ....................................................................................................................33
Goglev D.A., D.J. Capstan, Tsirel V.S. .................................................................................................................... 33
ON NECESSITY OF GEOLOGICAL ENVIRONMENT MODEL COMPLICATION FOR
MONITORING ITS STATE AND FORECAST ITS STABILITY .....................................................34
Hachay O.1, Khachay O.
2, Khachay A.
2 .................................................................................................................. 34
NATURAL ULF PERTURBATIONS OF THE ELECTRIC FIELD IN COASTAL ZONES ...........35
Ismagilov V.S., Kopytenko Yu.A. .......................................................................................................................... 35
DEEP MAGNETOTELLURIC SOUNDING OF THE NORTHERN PART OF THE SCYTHIAN
PLATE.......................................................................................................................................................35
Kushnir A.N.1, Bryashko N.V.
2 .............................................................................................................................. 35
MT/MV STUDIES OF THE KIROVOGRAD ANOMALY OF ELECTRIC CONDUCTIVITY IN
THE SOUTHERN OF THE DENIPER-DONETSK BASIN SLOPE .................................................36
Kushnir A.N., Burakhovych T.K, Ilyenko V.A. ........................................................................................................ 36
DEEP ELECTRIC CONDUCTIVITY OF THE AVACHA-KORYAKSKIY GROUP OF
VOLCANOES, KAMCHATKA ...............................................................................................................37
Yu. F. Moroz1,2
, V.A. Loginov1 ............................................................................................................................... 37
PECULIARITIES IN GEOELECTRICAL STRUCTURE OF KAMCHATKA EAST COAST ........38
Moroz Yu.F.1,2
, Samoylova O.M.1 ......................................................................................................................... 38
DEEP GEOPHYSICAL MODEL OF THE AREA BETWEEN SHANUCH COPPER-NICKEL
DEPOSIT AND AGINSKOYE GOLD DEPOSIT IN KAMCHATKA ................................................38
Moroz U.F., Ulybyshev I.S. ................................................................................................................................... 38
THE INFLUENCE OF THE DAILY TEMPERATURE ON RESISTIVITY OF SULFIDE MINE
TAILINGS .................................................................................................................................................39
Osipova P.S., Olenchenko V.V., Bortnikova S.B., Yurkevich N.V. .......................................................................... 39
5
ABOUT MEASUREMENT OF VERTICAL COMPONENT OF ELECTRIC FIELD AT
MAGNETOTELLURIC SOUNDING .....................................................................................................40
Plotkin V.V., Mogilatov V.S. ................................................................................................................................. 40
ABOUT THE ROLE OF THE HALL EFFECT AT MAGNETOTELLURIC SOUNDING ..............41
Plotkin V.V., Mogilatov V.S. ................................................................................................................................. 41
INFLUENCE OF MOSCOW MEGACITY ON NEAR-SURFACE ELECTRIC FIELD VARIATIONS
....................................................................................................................................................................41
Riabova S.A., Spivak A.A. ..................................................................................................................................... 41
FEYNMAN CORRECTIVE ELECTRICAL FIELD ..............................................................................42
B.G. Sapozhnikov ................................................................................................................................................. 42
INFLUENCE OF DISPLACEMENT CURRENTS ON THE RESULTS OF FREQUENCY
SOUNDINGS ON THE EXAMPLE OF THE RESULTS OF THE EXPERIMENT "KOVDOR
2015" ........................................................................................................................................................42
Shevtsov A.N. ...................................................................................................................................................... 42
THE SOLUTION OF THE 2-DIMENSIONAL INVERSE MESD PROBLEM ON THE
SELIVANOV-HIITOLA-SORTAVALA-SUISTAMO (NORTHERN LADOGA) ............................43
Shevtsov A.N., Kolesnikov V.E. ............................................................................................................................. 43
SEISMOACOUSTIC TOMOGRAPHY ON JET GROUTING ............................................................44
Shmurak Denis1, Shishkina Mary
2 ........................................................................................................................ 44
2D MODELING OF AMT DATA ON THE LADOGA AND PECHENGA STRUCTURES............44
Skorokhodov A.A. ................................................................................................................................................ 44
ON THE NATURE OF THE LADOGA CONDUCTION ANOMALY - GRAPHITES AND (OR)
FLUIDS? ...................................................................................................................................................45
Zhamaletdinov A.A1,2
, Sokolova E.Yu.3,4
, LADOGA Working Group ....................................................................... 45
LITHOSPERIC CURRENT SOURCES AND THEIR IMPACT ON POWER GRIDS ....................45
Vakhnina V.V., Gorokhov I.V. ............................................................................................................................... 45
6
INVESTIGATION OF SIGNALS OF GEOACOUSTIC EMISSIONS AND ELECTROMAGNETIC
RADIATION IN EXPLORATION AND DEEP WELLS ....................................................................46
Alexey Vdovin, Yurie Astrakhantsev, Nadejda Beloglasova and Evgenia Bajenova .............................................. 46
POSSIBILITIES OF THREE–COMPONENT GEOACOUSTIC LOGGING AT HYDROCARBON
DEPOSITS ................................................................................................................................................47
Alexey Vdovin, Nadejda Beloglasova, Yurie Astrakhantsev and Evgenia Bajenova .............................................. 47
STATISTICAL RELATIONSHIPS BETWEEN VARIATIONS OF THE GEOMAGNETIC FIELD,
AURORAL ELECTROJET, AND GEOMAGNE-TICALLY INDUCED CURRENTS ......................48
A.V. Vorobev1, V.A. Pilipenko
2,3, Ya.A. Sakharov
4, V.N. Selivanov
5 ....................................................................... 48
ABOUT THE INFLUENCE OF GEOMAGNETIC ACTIVITY ON METROLOGICAL
CHARACTERIS-TICS OF MAGNETIC INCLINOMETRIC SYSTEMS ...........................................49
Vorobeva G.R., Vorobev A.V. ............................................................................................................................... 49
SAMOYLOVSKY ISLAND - NEW INTERNATIONAL POLAR RESEARCH STATION; FIVE
YEARS UNDER OPERATION OF IPGG .............................................................................................50
Igor Yeltsov .......................................................................................................................................................... 50
JOINT INTERPRETATION OF GEOPHYSICAL AND GEOCHEMICAL FIELDS BASED ON
THEIR ANALYTICAL CONTINUATION DOWN. ............................................................................51
Ermokhin Konstantin M1, Zhdanova Ludmila A.
2 ................................................................................................. 51
EXPERIMENTAL VERIFICATION OF METHOD FOR MEASURING THE EFFECTS OF
INDUCED POLARIZATION OF DEEP OBJECTS IN NATURAL ELECTROMAGNETIC FIELDS
....................................................................................................................................................................52
Ermokhin K.M., Kopytenko Yu.A., Petrishchev M.S., Sergushin P.A. .................................................................... 52
ON THE BOUNDARY BETWEEN THE BRITTLE AND DUCTILE PARTS OF THE EARTH'S
CRUST ......................................................................................................................................................53
Zhamaletdinov A.A.1,2
.......................................................................................................................................... 53
EXPERIMENT "MURMAN-2018" ON THE STUDY OF THE DEEP GEOELECTRIC
BOUNDARIES IN THE EARTH'S CRUST WITH THE USE OF DC AND INDUCTION
SOUNDING METHODS .........................................................................................................................53
Zhamaletdinov AA1,2,3
, Shevtsov AN1, Skorokhodov AA
1, Kolobov VV
3, Ivonin V.V.
3 ............................................ 53
7
NEW DATA ON THE NATURE AND STRUCTURE OF THE LADOGA ANOMALY FROM DC
AND AMT RESEARCH ..........................................................................................................................54
Zhamaletdinov A.A.1,2
, Shevtsov A.N. 2
, Skorohodov A.A.2, Kolesnikov V.Ye.
2, Nilov M.Yu.
3 ................................ 54
SECTION P. PALEOMAGNETISM AND ROCK MAGNETISM ......................................................55
Conveners - Dr. P.V. Kharitonskii, Dr. A.A. Kosterov, Dr. E.S. Sergienko ............................................................... 55
INFLUENCE OF STRESS’ MATRIX ON THE INCLUSION DEFORMATION..............................55
Afremov L.L., Anisimov S.V. ................................................................................................................................. 55
PALEOMAGNETIC, ROCK-MAGNETIC AND GEOCHEMICAL PROPERTIES OF THE
RIPHEAN INTRUSIVE BODIES OF THE NORTHERN PART OF THE BASHKIRIAN
MEGAZONE (THE SOUTHERN URALS) ..........................................................................................56
Anosova M.B.1, Latyshev A.V.
1,2, Khotylev A.O.
1 .................................................................................................. 56
MAGNETIC MINERALOGY OF SAMPLES WITH L-SHAPED ARAI-NAGATA DIAGRAMS ..57
Aphinogenova N.A., Smirnov M.A., Gribov S.K. ................................................................................................... 57
CHARACTERISTICS OF THE MAGNETIC SUSCEPTIBILITY OF SPIN GLASSES ...................58
Belokon V.I., Chibiryak E.V, Trofimov A.N, Dyachenko O.I. .................................................................................. 58
FIRST MAGNETOSTRATIGRAPHIC DATA ON THE UPPER CAMBRIAN OF THE KEY
SECTION OF THE CHOPKO RIVER (NW SIBERIAN PLATFORM) ...........................................59
Chmerev V.S., Pavlov V.E., Rudko D.V. ................................................................................................................. 59
THE FIRST PALEOMAGNETIC AND PETROMAGNETIC DATA OF TAKYR DEPOSITS IN
WEST TURKMENISTAN ......................................................................................................................59
Elena Degtyareva ................................................................................................................................................. 59
THE SUBDUCTION ZONES EFFECT ON THE STRUCTURE OF THE SMALL-SCALE
CURRENTS AT CORE-MANTLE BOUNDARY .................................................................................60
Demina I., Gorshkova N., Ivanov S., Merkuryev S. ............................................................................................... 60
INTERPRETATION OF MAGNETIC ANOMALIES IN CONDITIONS OF PRESENCE OF
RESIDUAL MAGNETIZATION AND OTHER COMPLICATIONS ................................................61
Konstantin M. Ermokhin ...................................................................................................................................... 61
8
MAGNETIC PROPERTIES OF SOILS FROM THE VOLGA-KAMA FOREST-STEPPE ............61
L.A. Fattakhova, L.R. Kosareva, A.A. Shinkarev .................................................................................................... 61
TECTONIC AND GEOLOGICAL RESTRICTIONS ON DEVELOPING APWP FOR NORTH
EURASIAN PLATE IN PERMIAN TIME ............................................................................................62
Fedyukin I.V. ........................................................................................................................................................ 62
ANALOGUE OF THE NEDUBROVO ANOMALOUS REMANENCE IN THE ZHUKOV RAVINE
SECTION, RUSSIAN BASIN: THE EVIDENCE FOR UNUSUAL BEHAVIOR OF
GEOMAGNETIC FIELD BEFORE PERMIAN-TRIASSIC BOUNDARY ........................................63
Fetisova A.M.1,2
, Veselovskiy R.V.1,2
, Mamontov D.A.1 ......................................................................................... 63
RATE AND FREQUENCY OF EXTREME GEOMAGNETIC FIELD INTENSITY VARIATIONS
....................................................................................................................................................................64
Yves Gallet1, Stanislava Yutsis-Akimova
1,2, Alexandre Fournier
1, Agnès Genevey
3, Marie Troyano
1, Phil
Livermore4, Maxime Le Goff
1, Michel Fortin
5, Shahrmardan Amirov
6 .................................................................. 64
THE UPPER CRETACEOUS PALEOMAGNETIC INVESTIGATION OF NORTHEAST OF
WESTERN SIBERIA ..............................................................................................................................65
Gnibidenko Z.N.1, Levicheva A.V.
1, Semakov N.N.
1, Marinov V.A.
2 ....................................................................... 65
PALEOMAGNETISM OF PALEOZOIC ROCKS OF THE EASTERN SLOPE OF THE SOUTH
URALS ......................................................................................................................................................65
Golovanova I.V., Danukalov K.N., Kosarev A.M., Sal’manova R.Yu. ..................................................................... 65
PALEOMAGNETISM OF ORDOVICIAN-SILURIAN VOLCANIC ROCKS ON THE WESTERN
SLOPE OF THE SOUTH URALS ..........................................................................................................66
Golovanova I.V., Danukalov K.N., Sergeeva N.D., Sal’manova R.Yu., Khatapov S.S. ............................................. 66
LABORATORY MODELING OF THELLIER-COE PALEOINTENSITY DETERMINATIONS ON
ROCKS BEARING TCRM ......................................................................................................................67
Gribov S.K.1, Shcherbakov V.P.
1,2,3, Aphinogenova N.A.
1, Smirnov M.A.
1 ............................................................. 67
PRELIMINARY COMPOSITE MAGNETOSTRATIGRAPHIC SECTION OF THE
VALANZHINIAN OF THE CRIMEAN MOUNTAINS .......................................................................67
Grishchenko V.A., Guzhikov A.Yu., Manikin A.G. ................................................................................................. 67
UPPER CRETACEOUS MAGNETOSTRATIGRAPHY OF LOWER VOLGA REGION ...............68
9
Guzhikova A.A., Guzhikov A.Yu., Manikin A.G., Grishchenko V.A. ........................................................................ 68
ESTIMATION OF THE POSITION OF ARCH. NOVAYA ZEMLYA AT THE PERMIAN TIME
ACCORDING TO PALEOMAGNETIC DATA ....................................................................................69
Iosifidi A. G.1,2
...................................................................................................................................................... 69
PALEOMAGNETIC STUDIES OF CARBONIFEROUS DEPOSITS OF THE RUSSIAN
PLATFORM .............................................................................................................................................70
Iosifidi A. G.1,2
, Sergienko E. S.3, Salnaia N. V.
4, Otmas N. M.
1, Zuravlev A. V.
5, Mikhailova V. A.
1, Popov V. V.
1,3,
Danilova A. V.1 ..................................................................................................................................................... 70
EXPLORING THE INFLUENCE OF THE GEOMAGNETIC POLARITY TIME SCALE ON
RESULTS OF THE GEOCHRONOLOGICAL AND GEOHISTORICAL ANALYSIS OF THE
MARINE MAGNETIC ANOMALIES ....................................................................................................71
S. A. Ivanov1 and S. A. Merkuryev
1,2 ..................................................................................................................... 71
THE AGGREGATION OF SUPERPARAMAGNETIC PARTICLES UNDER IN-PHASE AND
ANTIPHASE OSCILLATIONS OF THEIR MAGNETIC MOMENTS .............................................72
Karimov F.H. ........................................................................................................................................................ 72
ROCK-MAGNETIC AND GRAIN SIZE DATA ON THE QUATERNARY MULTI-LAYERED KEY
SECTION TOLOGOY (BURYATIA, RUSSIA) ...................................................................................73
Kazansky A.Yu.1,2
, Matasova G.G.3, Shchetnikov A. A.
4, 5, 6, Filinov I. A.
4,5,6 ........................................................... 73
MAGNETIC PROPERTIES OF BRICKS: SUPERPARAMAGNETISM AND PRESENCE OF
HIGH-COERCIVITY-LOW-UNBLOCKING-TEMPERATURE MAGNETIC PHASE ..................74
P.V. Kharitonskii1, A. Kosterov
2, I.M. Berestnev
2, E.S. Sergienko
2 ......................................................................... 74
PETROMAGNETIC LEGEND OF THE BASIS OF THE EASTERN BOARD OF THE TUNGUS
SYNECLISE (WORKING OPTION) ....................................................................................................75
Alexander A. Kirguev1, Konstantin M. Konstantinov
1,2, Alexanderа E. Vasilyeva
3 ................................................. 75
PETRO- AND PALEOMAGNETIC CHARACTERISTICS OF KIMBERLITES AND BASITES IN
THE KYUTINGDE GRABEN (NORTHEASTERN SIBERIAN PLATFORM)...............................76
Innokentiy K. Konstantinov1, Konstantin M. Konstantinov
1,2, Mikhail D. Tomshin
3, Dimitri P. Gladkochub
1,
Andrey A. Jakovlev2, Alexandra E. Vasil’eva
3........................................................................................................ 76
PALEOMAGNETIC CHARACTERISTICS OF DOLERITE DYKES OF THE VILUY-MARKHA
FAULT ZONE (YAKUT DIAMONDIFEROUS PROVINCE) ...........................................................77
10
Konstantin M. Konstantinov1,2
, Shamil Z. Ibragimov3, Innokentiy K. Konstantinov
2, Alexander A. Kirguev
1, Mikhail
D. Tomshin4, ........................................................................................................................................................ 77
PALEOMAGNETISM OF DOLERITE DIKES OF THE CHARA-SINSK FAULT ZONE (ALDAN
BLOCK OF THE SIBERIAN PLATFORM) .........................................................................................78
Konstantin M. Konstantinov1,2
, Innokentiy K. Konstantinov2, Shamil Z. Ibragimov
3, Mikhail D. Tomshin
4, Andrey
A. Jakovlev1 ......................................................................................................................................................... 78
THE MAGNETIC PROPERTIES OF LAKE TURGOYAK SEDIMENTS (CHELYABINSK
REGION, RUSSIA) ..................................................................................................................................79
L. Kosareva 1, D. Nurgaliev
1, P. Krylov
1, D. Kuzina
1, V. Antonenko
1, A. Yusupova
1, V. Vorob’ev
2, V. Evtygin
2 .. 79
HIGH-FIELD HYSTERESIS AND LOW-TEMPERATURE MAGNETIC PROPERTIES OF
HEMATITE- AND GOETHITE-BEARING SEDIMENTS ................................................................79
A. Kosterov1, E. Sergienko
1, A. Iosifidi
2,3, S. Yanson
1 ............................................................................................. 79
PALEOMAGNETISM OF PHANEROZOIC GEOLOGICAL COMPLEXES OF MONGOLIA AND
TUVA ........................................................................................................................................................80
D.V. Kovalenko .................................................................................................................................................... 80
RHYTHMS OF THE PALEOINTENSITY CHANGES WITH CHARACTERISTIC TIMES 5 AND
1 MA ..........................................................................................................................................................81
A.Yu. Kurazhkovskii, N.A.Kurazhkovskaya, B.I.Klain ............................................................................................. 81
RESULTS OF MAGNETIC AND PALEOMAGNETIC INVESTIGATIONS OF BABYI KAMEN’
SECTION, KEMEROVO REGION ........................................................................................................82
D. Kuzina1, I. Gilmetdinov
1, R. Aupov
1, Yu. Balabanov
1, L. Kosareva
1, S. Zorina
1, V. Silantiev
1, V. Davydov
1, 2 ...... 82
EARTH’S CRATER MAGNETIC ANOMALIES: NUMERICAL MODELING OF SIMPLE
CRATERS .................................................................................................................................................82
M. Yu. Kuzmicheva .............................................................................................................................................. 82
ANISOTROPY OF MAGNETIC SUSCEPTIBILITY IN THE PERMIAN-TRIASSIC
INTRUSIONS FROM THE NORTHWESTERN SIBERIAN PLATFORM: IMPLICATIONS FOR
THE MAGMA TRANSPORT PATTERNS ..........................................................................................83
Latyshev A.V.1,2
, Ulyahina P.S.2, Krivolutskaya N.A.
3 ............................................................................................ 83
PALEOPROTEROZOIC TRENDS OF REMAGNETIZATION FOR THE KARELIAN CRATON:
MYTH OR REALITY ..............................................................................................................................84
11
Lubnina N.V., Tarasov N.A., Zakharov V.S. ........................................................................................................... 84
KEY EARLY PALEOPROTEOROZOIC 2.45 GA PALEOMAGNETIC POLE FOR THE
KARELIAN CRATON: FURTHER PALEOMAGNETIC EVIDENCE ..............................................85
Lubnina N.V., Tarasov N.A. .................................................................................................................................. 85
EXPERIMENTAL MODELING OF CHEMICAL MAGNETIZATION IN OCEANIC BASALTS
AND ITS PROPERTIES .........................................................................................................................85
Maksimochkin V.I., Grachev R.A., Tselebrovskiy A.N. .......................................................................................... 85
DETERMINATION OF PALEOINTENSITY OF GEOMAGNETIC FIELD ON THE VOLCANOES
LAVAS OF KAMCHATKA .....................................................................................................................86
V.I. Maksimochkin1)
, Yu.V. Sleptsova1)
, A.N. Nekrasov2)
....................................................................................... 86
INTERRELATIONS BETWEEN THE GRANULOMETRIC COMPOSITION, MAGNETIC
PROPERTIES AND GEOCHEMICAL INDICATORS IN THE SUBAERIAL DEPOSITS OF THE
ARCHAEOLOGICAL SITE "TUYANA" (TUNKA DEPRESSION, BAIKAL REGION, RUSSIA)
....................................................................................................................................................................87
Matasova G.G.1, Shchetnikov A. A.
2,3,4, Kazansky A.Yu.
5,6, Filinov I. A.
2,3,4 ............................................................ 87
PRELIMINARY ESTIMATION OF THE NON-DIPOLE PART OF THE GEOMAGNETIC FIELD
IN THE QUATERNARY PERIOD BASED ON THE INVESTIGATION OF MARINE
MAGNETIC ANOMALIES ON THE CARLSBERG RIDGE ..............................................................88
Merkuriev S.A.1,2
, Demina I.M.1, Ivanov S.A.
1 ....................................................................................................... 88
PRELIMINARY MAGNETIC INVESTIGATIONS OF LAKE BOLSHOE MIASSOVO
SEDIMENTS (CHELYABINSK REGION, RUSSIA) ..........................................................................89
D. Nurgaliev, D. Kuzina, P. Krylov, L Kosareva, V. Antonenko, P. Yasonov, A. Yusupova ...................................... 89
METHODOLOGY FOR LOW FLYING AEROMAGNETIC SERVICE WITH THE USE OF UAV
....................................................................................................................................................................90
Parshin A.V.1, Tsirel V.S.
2, Rzhevskaya A.K.
3 ......................................................................................................... 90
PALEOMAGNETISM OF THE UDZHA AND OLENEK UPLIFTS, NORTHERN SIBERIA .......91
Pasenko A.M.1, Malyshev S.V.
2 ............................................................................................................................ 91
METALLIC IRON IN BASALTIC LAVA RIVER FROM MALY YENISEI (TUVA, RUSSIA): THE
RESULTS OF THERMOMAGNETIC STUDY ....................................................................................92
12
Pechersky D.M.1, Kazansky A.Yu.
2, 3, Kozlovskiy A.M.
4, Kuzina D.M.
5, Markov G.P.
1 ............................................. 92
THE AVERAGE SIZE OF IRON PARTICLES VS. THE AGES OF LUNAR BASALTS ................93
D.M. Pechersky, G.P. Markov .............................................................................................................................. 93
PETROMAGNETIC AND MICROPROBE STUDIES OF PEAT DEPOSITS (PRELIMINARY
RESULTS) ................................................................................................................................................94
Peskov A.Yu.1, Chakov V.V.
2, Klimin M.A.
2, Krutikova V.О.
1, Zakharchenko Е.N.
2, Arkhipov М.V.
1, Didenko А.N.
1,3
............................................................................................................................................................................ 94
PALEOMAGNETISM OF THE PIONERSKAYA FORMATION; CONTRIBUTION TO THE
GEODYNAMIC MODEL OF THE SIKHOTE-ALIN OROGENIC BELT .........................................95
Peskov А.Yu.1, Arkhipov M.V.
1, Kudymov A.V.
1, Didenko A.N.
1, 2 ......................................................................... 95
MAGNETIC PROPERTIES OF SEDIMENTARY ROCKS FROM PIONERSKAYA AND
GORINSKAYA FORMATIONS (JUNCTION ZONE BETWEEN THE SIKHOTE-ALIN AND
MONGOL-OKHOTSK OROGENIC BELTS) .......................................................................................95
Peskov A.Yu. ........................................................................................................................................................ 95
IDENTIFICATION OF MAGNETIC CHRONS BY COMPONENTS OF MARINE BAND
ANOMALIES ............................................................................................................................................96
A.A.Petrova, Yu.A.Kopytenko .............................................................................................................................. 96
ARHEOMAGNETIC STUDIES OF NEOLITHIC CERAMICS OF VEKSA ARCHEOLOGICAL
SITE (CONTINUATION) ......................................................................................................................97
Pilipenko O.V., Nachasova I.E., Markov G.P. ........................................................................................................ 97
NEOPROTEROZOIC GLACIAL DEPOSITS OF SIBERIA: THE PROS AND CONS OF
SNOWBALL EARTH HYPOTHESIS ...................................................................................................98
Andrey Shatsillo1, Dmitriy Rudko
1, Sergey Rudko
2,3, Irina Latysheva
2, Nikolay Kuznetsov
2 .................................. 98
CYCLOSTRATIGRAPHIC ANALYSIS OF LOPATA FORMATION (NE OF ENISEY RIDGE,
WESTERN SIBERIAN PLATFORM): MORE ON HYPERACTIVITY OF GEOMAGNETIC
FIELD IN THE LATE PRECAMBRIAN ..............................................................................................98
Dmitriy Rudko1, Sergey Rudko
2, Andrey Shatsillo
1, Nikolay Kuznetsov
2 ............................................................... 98
BERYLLIUM AND RELATIVE PALEOINTENSITY SIGNALS DURING THE LAST
GEOMAGNETIC REVERSAL ................................................................................................................99
13
Tatiana Savranskaia1, Jean-Pierre Valet
1, Laure Meynadier
1, Franck Bassinot
2, Quentin Simon
3, Didier Bourlès
3,
Nicolas Thouveny3 ............................................................................................................................................... 99
APPLYING THE MAGNETIC FORCE MICROSCOPY TO EVALUATE THE MAGNETIC
STATES IN ROCKS ............................................................................................................................. 100
E.S. Sergienko1, S.Yu. Yanson
1, I.A. Vasilyeva
1, M.S. Lozhkin
1, A. Kosterov
1, P.V. Kharitonskii
2 .......................... 100
NEW 1.86 GA PALEOINTENSITY DATA FROM THE KOLA PENINSULA INTRUSIONS, NE
FENNOSCANDIA ................................................................................................................................. 101
Shcherbakova V.V.1, Veselovskiy R.V.
2,3, Shcherbakov V.P.
1, Zhidkov G.V.
1, Smirnov M.A.
1 ............................... 101
PARADOXES IN THE LATITUDE DISTRIBUTION OF THE GEOMAGNETIC FIELD VECTOR
IN THE BRUNHES CHRON ............................................................................................................... 102
Shcherbakov, V.P.1,2,3
, Khokhlov, A.V.2,4
, Sycheva, N.K.1 .................................................................................... 102
CHECKING THE DIMENSIONS OF COULOMB'S LAW FOR STATIONARY MAGNETIC
FIELD AND THE DETERMINATION OF THE DISTANCES TO THE ELEMENTARY
SOURCES IN MAGNETOMETRY ..................................................................................................... 102
Sorokin A.G. ....................................................................................................................................................... 102
ANALYTIC SCALING LAWS IN PLANETARY DYNAMO MODELS .......................................... 103
Starchenko S.V. .................................................................................................................................................. 103
VARIATIONS OF ENERGY AND POWER FOR A POTENTIAL GEOMAGNETIC FIELD SINCE
1840 ...................................................................................................................................................... 104
S.V. Starchenko and S.V. Yakovleva ................................................................................................................... 104
RECONSTRUCTION OF JURASSIC SEDIMENTARY ENVIRONMENTS USING ROCK-
MAGNETIC DATA IN THE MIKHAYLOVTSEMENT REFERENCE SECTION (RYAZAN
REGION, RUSSIA) ............................................................................................................................... 105
Stepanov I.A.1, Kazansky A.Yu.
1,2, Kosareva L.R.
3, Rogov M.A.
2, Tesakova E.M.
1,2, Shchepetova E.V.
2 ................ 105
СOMPUTER MODELING OF THELLIER AND WILSON METHODS ON SD GRAINS
CARRYING TRM AND CRM .............................................................................................................. 106
Sycheva, N.K.1, Shcherbakov, V.P.
1,2 .................................................................................................................. 106
STRUCTURAL TRANSFORMATIONS OF TITANOMAGNETITE IN NATURAL BASALTS OF
THE RED SEA DURING OXIDATION ............................................................................................. 106
14
Tselebrovskiy A. N., Maksimochkin V. I., Grachev R. A. ...................................................................................... 106
MORPHOLOGY AND COMPOSITION OF FOSSIL COSMIC DUST FROM VARIOUS
SOURCES .............................................................................................................................................. 107
Tselmovich V.A.1, Kuzina D.M.
2, Nourgaliev D.K.
2, Garin E.V.
3. Philippov D.A.
3 .................................................. 107
THE POSSIBILITY OF DETERMINING THE AGE OF THE NORASHEN SECTION OF LAKE
SEVAN ................................................................................................................................................... 108
A.A. Vardanyan, R.Y. Stakhovskaya ................................................................................................................... 108
ESTIMATION OF SUITABILITY OF SEDIMENTS OF THE SECTION OF DZKNAGNET
RIVER FOR STUDYING THE FINE STRUCTURE OF GEOMAGNETIC FIELD ...................... 109
A.A. Vardanyan, R.Y. Stakhovskaya ................................................................................................................... 109
FOUR INDEPENDENT ISOTOPIC GEOCHROMETERS IN PALEOPROTEROZOIC
DOLERITES FROM THE KOLA PENINSULA AS THE BASIS FOR THE NEW ~1.86 GA
FENNOSCANDIAN KEY PALEOMAGNETIC POLE ..................................................................... 110
Veselovskiy R.V.1,2,3
, Samsonov A.V.3, Stepanova A.V.
4, Sal’nikova E.B.
5, Larionova Yu.O.
3, Travin A.V.
6,
Arzamastsev A.A.5, Egorova S.V.
4, Erofeeva K.G.
3, Stifeeva M.V.
5, Esenkov A.A.
1, Chistyakova A.V.
1 ................. 110
ROCK MAGNETISM AND PALEOMAGNETISM OF THE EDIACARAN SEDIMENTS OF THE
YENISEI RIDGE VOROGOVKA SERIES ......................................................................................... 111
E.V. Vinogradov, D.V. Metelkin, V.V. Abashev ................................................................................................... 111
DATE OF TRM OF GRANITE BATHOLITH: IS IT POSSIBLE? ................................................ 112
Vodovozov V.Yu.1,2
, Zakharov V.S.1, Zverev A.R.
1,2, Travin A.V.
3 ......................................................................... 112
CORRECTION FOR A WEAK RESIDUAL MAGNETIC FIELD IN THE FURNACE DURING
THE PALEOINTENSITY DETERMINATION BY THELLIER-COE METHOD ........................ 112
Zhidkov G.V. ...................................................................................................................................................... 112
PALEOMAGNETISM OF THE EARLY PROTEROZOIC BASITE COMPLEXES OF THE
OLEKMA BLOCK OF THE SOUTH OF THE SIBERIAN CRATON ............................................ 113
Zverev A.R.1,2
, Vodovozov V.Yu.1,2
...................................................................................................................... 113
SECTION S. SEISMOLOGY ................................................................................................................ 115
Conveners - Prof. T.B. Yanovskaya, Prof. V.N. Troyan ........................................................................................ 115
15
TECTONIC PLATES MICROMOTIONS CAUSED BY THE CHANDLER WOBBLE ............... 115
Blagoveshchenskaya Elena ................................................................................................................................ 115
SHORT-TERM PRECURSORS OF EARTHQUAKES .................................................................... 116
Dovbnya B.V. ..................................................................................................................................................... 116
NEW DATA ABOUT LOW MAGNITUDE SEISMICITY OF THE GAKKEL RIDGE ON THE
DATA OF CONTINUOUS REGIONAL MONITORING ................................................................. 117
Fedorenko I.V. ................................................................................................................................................... 117
SEISMICITY AND CRUSTAL STRUCTURE OF THE SOUTHERN CRIMEA AND ADJACENT
NORTHERN BLACK SEA FROM LOCAL SEISMIC TOMOGRAPHY ........................................ 118
Gobarenko V.1, Yegorova T.
2 .............................................................................................................................. 118
APPLICATION OF THE RECEIVER FUNCTION TECHNIQUE IN AREAS WITH A LOW-
VELOCITY NEAR-SURFACE LAYER .............................................................................................. 119
Goev A.G.1, Kosarev G.L.
2, Sanina I.A.
1 ............................................................................................................... 119
HIGH-SENSITIVITY SENSOR FOR CORRECTION OF INSTRUMENTAL THERMAL NOISE
OF SEISMIC DEVICES ........................................................................................................................ 120
Gravirov V.V. 1, 2
, Kislov K.V. 1
, Likhodeev D.V.2 .................................................................................................. 120
PEMSDAS - PORTABLE EXPANDABLE MODULAR SEISMIC DATA ACQUISITION SYSTEM
................................................................................................................................................................. 120
Gravirov V.V. 1, 2
, Kislov K.V. 1, Sobisevich A.L.
2, Sobisevich L.E.
2 ....................................................................... 120
ATLAS OF THE AFTERSHOCKS: TO THE 150TH ANNIVERSARY OF FUSAKICHI OMORI
................................................................................................................................................................. 121
Guglielmi A.V.1, Zotov O.D.2, Zavyalov A.D.1 .................................................................................................... 121
NEW MACROSEISMIC MANIFESTATIONS OF EARTHQUAKES IN THE VRANCH AREA ON
THE TERRITORY OF UKRAINE...................................................................................................... 121
Ilyenko V.A., Kushnir A.N. .................................................................................................................................. 121
SOME REMARKS ON THE SEISMOMETRIC EXPERIMENTS TAKING INTO ACCOUNT THE
THICKNESS OF THE FROZEN LAYER SOIL ................................................................................. 122
Kislov K.V.1, Gravirov V.V.
1, 2 .............................................................................................................................. 122
16
ON THE QUESTION OF THE ROTATIONAL SEISMOLOGY ..................................................... 123
Kislov K.V.1, Gravirov V.V.
1, 2 .............................................................................................................................. 123
SEISMICITY IN THE AREA OF NORTH SEA ROUTE ................................................................. 123
Konechnaya Y.V.1, Fedorenko I.V.
2 ..................................................................................................................... 123
POSSIBLE SHORT-TERM IONOSPHERIC PRECURSORS OF STRONG CRUSTAL
EARTHQUAKES .................................................................................................................................. 124
Korsunova L. P.1, Legenka A. D.
1, Hegai V. V.
1 .................................................................................................... 124
HETEROGENEITIES OF THE EARTH'S INNER CORE BOUNDARY FROM DIFFERENTIAL
MEASUREMENTS OF PKIKP AND PCP SEISMIC PHASES....................................................... 124
Dmitry Krasnoshchekov, Vladimir Ovtchinnikov ................................................................................................ 124
RADIAL ANISOTROPY OF THE EUROPEAN UPPER MANTLE FROM RECORDS OF
EARTHQUAKES AND SEISMIC NOISE .......................................................................................... 125
E.L.Lyskova, T.Yu.Koroleva, T.B.Yanovskaya ...................................................................................................... 125
SOFTWARE SERVICE «SEISMOLOGY ONLINE» ........................................................................ 126
Mikhailova Yana1, Morozov Alexey
2 .................................................................................................................. 126
GEODYNAMICS OF THE EAST-EUROPEAN CRATON BASED ON UP-TO-DATE GNSS
DATA ..................................................................................................................................................... 127
A. V. Mokhnatkin1, V. L. Gorshkov
1, N. V. Scherbakova
1, B. A. Assinovskaya
2 .................................................... 127
NATURAL AND TECHNOGENIC SEISMIC AND GEODYNAMIC ACTIVITY OF THE
SOUTHERN URALS ............................................................................................................................ 127
Nesterenko M. Yu. ............................................................................................................................................. 127
ANALYSIS OF THE SPATIAL DISTRIBUTION OF THE EARTHQUAKE FOCAL
MECHANISMS IN THE KURIL-OKHOTSK REGION ................................................................... 128
Polets A.Yu. ....................................................................................................................................................... 128
FEATURES OF THE TECTONIC STRESS FIELD IN THE OKHOTSK SEA AND JAPANESE
REGIONS ............................................................................................................................................... 129
Polets A.Yu. ....................................................................................................................................................... 129
17
SPLITTING OF EARTH'S FUNDAMENTAL SPHEROIDAL MODE 0S2 IN GEOMAGNETIC
VARIATIONS ....................................................................................................................................... 130
Riabova S.A., Spivak A.A. ................................................................................................................................... 130
DEEP VELOCITY SRTUCTURE OF THE ARCTIC REGION FROM RAYLEIGH WAVE
DISPERSION DATA ............................................................................................................................ 131
Alena Seredkina ................................................................................................................................................. 131
SUPERDEEP DRILLING AND ITS EFFECT ON THE SEISMIC MODELS OF THE
FENNOSCANDIAN SHIELD .............................................................................................................. 131
Sharov N.V. ........................................................................................................................................................ 131
SELF-SIMILARITY ANALYSIS OF EARTHQUAKES AND ACTIVE FAULTS WITHIN THE
SIKHOTE-ALIN OROGENIC BELT AND NEIGHBORING AREAS ............................................ 132
Zakharov V.S. 1,3
*, Didenko A. N. 2,4
, Gil’manova G.Z. 2
, Merkulova T.V. 2
............................................................ 132
ON THE SPATIAL-TEMPORAL STRUCTURE OF AFTERSHOCK SEQUENCES ................... 133
Zotov O.D.1, Zavyalov A.D.
2, Klain B.I.
1 ............................................................................................................... 133
STP. SOLAR-TERRESTRIAL PHYSICS .......................................................................................... 134
Conveners - Dr. N.V.Zolotova, Dr. A.V.Divin ....................................................................................................... 134
EMPIRICAL MAGNETOSPHERIC MODELS FOR SIR- AND CME-DRIVEN MAGNETIC
STORMS ................................................................................................................................................ 134
Andreeva V. A.1, Tsyganenko N. A.
1 ................................................................................................................... 134
DEPRESSION OF THE TOTAL FLUX OF SOLAR ELECTROMAGNETIC RADIATION
DURING THE GENERATION OF RELATIVISTIC PROTONS OF SOLAR COSMIC RAYS ... 135
Avakyan S.V. 1
, Nicvol’skii G.A. 2
......................................................................................................................... 135
HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE? FORMATION OF
ASSOCIATES IN HIGH DELUTED WATER BIOSOLUTIONS UNDER THE INFLUENCE OF
THE MICROWAVE FLUX FROM THE IONOSPHERE ............................................................... 136
Avakyan S.V. 1
, Baranova L.A. 2
........................................................................................................................... 136
HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE?2. DNA, IONOSPHERIC
MICROWAVES AND WATER ........................................................................................................... 137
18
Avakyan S.V. 1
, Baranova L.A.
2 ........................................................................................................................... 137
INFLUENCE OF DIFFERENT IONOSPHERIC DISTURBANCES ON THE GPS
SCINTILLATIONS AT HIGH LATITUDES ..................................................................................... 138
V.B. Belakhovsky1, Y. Jin
2, W.J. Miloch
2 .............................................................................................................. 138
ON THE CORRELATION BETWEEN LOCAL CRUSTAL MAGNETIC FIELD OF THE MOON
AND ION REFLECTION ..................................................................................................................... 138
R. Belyaev1, A. Divin
1, V. Semenov
1, I. Zaytsev
1 .................................................................................................. 138
IONOSPHERE CHARACTERISTICS DURING SIMILAR GEOMAGNETIC EVENTS ............. 139
Blagoveshchensky D.V.1, Sergeeva M.A.
2, Shmelev Yu.A.
1 ................................................................................. 139
PERSPECTIVES OF MONITORING OF ATMOSPHERIC ELECTRIC FIELD IN THE CENTRAL
PART OF KAMCHATKA PENINSULA TO DETECT ATMOSPHERIC-ELECTRIC EFFECTS
FROM VOLCANIC ERUPTIONS ....................................................................................................... 139
Cherneva N.V.1, Firstov P.P.
1,2, Akbashev R.R.
2, Malkin E.I.
1 ............................................................................... 139
DEFINITION OF TEMPERATURE AND SONIC SPEED VALUES AT THE MESOSPHERIC
HEIGHTS FROM VARIATIONS OF PARTIAL REFLECTION RADAR SIGNALS .................. 140
Cherniakov S.M., Turyansky V. A. ...................................................................................................................... 140
COSMIC RAY CUTOFF RIGIDITY CHANGES CAUSED BY THE DISTURBED
GEOMAGNETIC FIELD OF THE STORM IN JUNE 2015 ........................................................... 140
Danilova1 O.A., Tyasto
1 M.I., Sdobnov
2 V.E. ....................................................................................................... 140
CONJUGATE GROUND-SPACECRAFT OBSERVATIONS OF VLF CHORUS ELEMENTS ... 141
A. G. Demekhov1,2
, J. Manninen3, O. Santolík
4.5, E. E. Titova
1 ............................................................................. 141
YOUNGER DRYAS AND RADIOCARBON DATA ......................................................................... 142
Dergachev V.A., Kudryavtsev I.V. ....................................................................................................................... 142
THEMIS AND MAIN CAMERA SYSTEM OBSERVATIONS - A CASE STUDY ....................... 142
I.V. Despirak1, T.V. Kozelova
1, B.V. Kozelov
1, A.A. Liubchich
1 ............................................................................. 142
COMPARISON OF DIFFERENT LATITUDE SUBSTORMS DURING TWO LARGE
MAGNETIC STORMS ......................................................................................................................... 143
19
I.V. Despirak1, N.G. Kleimenova
2, V. Guineva
3.................................................................................................... 143
LARGE-SCALE TYPES OF THE SOLAR WIND AND APPEARANCE OF MAGNETIC
SUBSTORMS ........................................................................................................................................ 144
I.V. Despirak1, A.A. Liubchich
1, N.G. Kleimenova
2 .............................................................................................. 144
COLLISIONLESS MAGNETIC RECONNECTION: 3D STRUCTURE OF JET FRONTS IN THE
PRESENCE OF A GUIDE FIELD ....................................................................................................... 144
A. Divin1, V. Semenov
1, I. Zaytsev
1 ..................................................................................................................... 144
ON THE SIMILARITY OF THE SERPENTINE EMISSION SPECTRA AT GEOMAGNETIC
POLES .................................................................................................................................................... 145
B.V. Dovbnya1, B.I. Klain
2 ................................................................................................................................... 145
STATISTICAL STUDY OF THE EFFECT OF THE SUBSTORM ACTIVITY ON THE
FORMATION OF NOISE ULF EMISSIONS IN THE FREQUENCY RANGE (0 – 7) HZ ......... 145
B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya ..................................................................................................... 145
SOME PECULIARITIES OF THE DIURNAL, SEASONAL AND CYCLIC VARIATIONS OF
MID-LATITUDE ULF EMISSIONS WITH RESONANCE STRUCTURE OF THE SPECTRUM
................................................................................................................................................................. 146
B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya ..................................................................................................... 146
THE ELECTRON ENERGY SPECTRA ON THE NIGHTSIDE (R = 6-11 RE) DURING
GEOMAGNETIC STORMS ................................................................................................................. 147
Dubyagin S.V.1, Ganushkina N. Y.
1,2 .................................................................................................................... 147
ELECTROMAGNETIC FIELDS OF MAGNETOSPHERIC ULF DISTURBANCES IN
CONJUGATE IONOSPHERES: CURRENT/VOLTAGE DICHOTOMY ...................................... 147
E.N. Fedorov 1, V.A. Pilipenko
2 .......................................................................................................................... 147
ANALYSIS OF CHEMICAL COMPONENTS OF POLAR WINTER ATMOSPHERE DURING
RELATIVISTIC ELECTRON PRECIPITATION ............................................................................. 148
Golubenko Kseniia1, Mironova Irina
1, Rozanov Eugene
2, Artamonov Anton
3 ..................................................... 148
THE INFLUENCE OF FORESHOCK ORIENTATION ON THE POLAR CUSPS OSCILLATIONS
................................................................................................................................................................. 148
Guglielmi A.V., Kozyreva O.V. ............................................................................................................................ 148
20
OBSERVATION OF THE PROTON AURORA DYNAMICS AND THE SAR ARC OCCURRENCE
AS A CONSEQUENCE OF THE INTENSE CONVECTION AND SUBSTORM .......................... 149
Ievenko I.B. ........................................................................................................................................................ 149
EASTWARD PROPAGATION OF THE PC1 WAVES ALONG THE PLASMAPAUSE
ACCORDING TO OBSERVATION OF THE DYNAMICS OF PROTON AURORA AND SAR
ARC ........................................................................................................................................................ 149
Ievenko I.B., Parnikov S.G., Baishev D.G. ........................................................................................................... 149
AN APPROACH TO REGIONAL THREE-DIMENSIONAL MODELLING OF GROUND
ELECTROMAGNETIC FIELD VARIATIONS DURING SPACE WEATHER EVENTS USING
RESULTS OF MAGNETOHYDRODYNAMIC MODELLING OF THE EARTH’S
MAGNETOSPHERE AND IONOSPHERE ....................................................................................... 150
Elena Ivannikova1,2
, Mikhail Kruglyakov1,3
, Alexey Kuvshinov1, Lutz Rastätter
4, Antti Pulkkinen
4 ...................... 150
BY IMF AND CLOUD RADIATIVE PROPERTIES AFFECT TO THE POLAR TROPOSPHERIC
PRESSURE THROUGH THE IONOSPHERIC POTENTIAL IMPACT TO GEC ....................... 151
Arseniy Karagodin 1, Mervyn P. Freeman
2, Mai Mai Lam
2, Eugene Rozanov
3, Irina Mironova
1 ........................... 151
CHANGES IN THE POSITION OF THE AURORAL OVAL UNDER CONDITIONS OF
DISPLACEMENT OF THE EARTH'S MAGNETIC POLE ............................................................. 152
Kopytenko Yu.A.1, Chernous S.A.
2 Petrova A.A.
1, Filatov M.V.
2 Petrishchev M.S.
1 ............................................. 152
ON APPLICATION OF ASYMMETRIC KAN-LIKE EXACT EQUILIBRIA TO THE EARTH
MAGNETOTAIL MODELING ............................................................................................................ 152
Daniil B. Korovinskiy1, 2 Darya I. Kubyshkina
1, 3 Vladimir S. Semenov
2, 4 Marina V. Kubyshkina
2, 5 Nikolai V.
Erkaev2,3,4
, 6 Ivan B. Ivanov5, 7 Stefan A. Kiehas
1 ............................................................................................... 152
THE DRIFT-COMPRESSION MODES IN THE MAGNETOSPHERIC PLASMA ..................... 153
Kostarev D.V.1, Mager P.N.
1, Klimushkin D.Yu.
1 ................................................................................................. 153
VIRTUAL MAGNETOGRAMS – NEW TOOL FOR THE STUDY OF SOLAR WIND-
MAGNETOSPHERE COUPLING ...................................................................................................... 153
Kozyreva O.V.1, Pilipenko V.A.
2, Soloviev A.A.
2 .................................................................................................. 153
INTERMITTENCY STATISTICS OF HIGH-LATITUDE GEOMAGNETIC PULSATIONS PI2
................................................................................................................................................................. 154
N.A.Kurazhkovskaya, B.I.Klain, I.A.Yelagina ....................................................................................................... 154
21
EFFECT OF THE SOLAR WIND AND IMF PARAMETERS ON POLARIZATION
CHARACTERISTICS OF HIGH-LATITUDE GEOMAGNETIC IMPULSES (MIES) ................ 155
N.A.Kurazhkovskaya, B.I.Klain ........................................................................................................................... 155
CONSTRAINING THE EARLY EVOLUTION OF VENUS AND EARTH BY REPRODUCING
ELEMNTAL RATIOS .......................................................................................................................... 155
Lammer H. ......................................................................................................................................................... 155
KELVIN-HELMHOLTZ INSTABILITY OF THE LOW-LATITUDE BOUNDARY LAYER OF
THE GEOMAGNETIC TAIL ............................................................................................................... 156
Leonovich A.S.1, Kozlov D.A.
1 ............................................................................................................................. 156
IONOSPHERIC DISTURBANCE CAUSED BY RADIATION OF CHELYABINSK BOLIDE
FLIGHT .................................................................................................................................................. 157
Losseva T.V.1, Golub’ A.P.
2, Lyakhov A.N.
1, Kosarev I.B.
1 ................................................................................. 157
SIMULTANEOUS OBSERVATIONS OF A COMPRESSIONAL PC5 WAVE BY EKB RADAR
IN THE IONOSPHERE AND BY VAN ALLEN PROBES IN THE MAGNETOSPHERE .......... 158
Mager O.V., Chelpanov M.A., Mager P.N., Klimushkin D.Yu., Berngardt O.I. ..................................................... 158
ELEMENTS OF FORECASTING OF SPACE WEATHER AND IONOSPHERIC PARAMETERS
................................................................................................................................................................. 158
Maltseva O.A.1, Bezvytnyj S.A.2, Morozov B.E.2, Shilov D.I.2, Shmelev J.A.2 .................................................... 158
MODELING AND ANALYSIS OF IONOSPHERIC CRITICAL FREQUENCY DATA ON THE
BASIS OF A MULTICOMPONENT MODEL ................................................................................... 159
Mandrikova O.V., Fetisova N.V., Polozov Yu.A. .................................................................................................. 159
ANALYSIS OF NEUTRON MONITORS DATA DURING THE PERIODS OF HELIOSPHERIC
DISTURBANCES ................................................................................................................................. 160
Mandrikova O.V., Zalyaev T.L., Mandrikova B.S. ................................................................................................ 160
IN SEARCH OF DISTURBANCES OF THE UPPER IONOSPHERE AND GEOMAGNETIC
FIELD ABOVE HURRICANES AS OBSERVED BY SWARM SATELLITES ............................. 161
1 Martines-Bedenko V.A.1, 2 Pilipenko V.A.1,2, 3 Zakharov V.I.3 ...................................................................... 161
NUMERICAL METHODS IN THE PROBLEM OF STUDYING THE EFFECT OF COSMIC RAYS
ON THE EARTH'S ATMOSPHERE .................................................................................................. 161
22
Maurchev E.A.1, Balabin Yu.V., Gvozdevsky B.V., Mikhalko E.A., Hermanenko A.V., Belakhovsky V.B. .............. 161
VALIDATION OF THE RESULTS OF MODELING THE PASSAGE OF COSMIC RAYS
THROUGH THE EARTH'S ATMOSPHERE BY EXPERIMENTAL DATA ............................... 162
Mikhalko E.A. 1
, Maurchev E.A., Germanenko A.V., Balabin Yu.V. ..................................................................... 162
A NUMERICAL MODEL OF THE HORIZONTAL AND VERTICAL WIND IN THE EARTH’S
ATMOSPHERE AND ITS IMPROVEMENTS ................................................................................. 162
Mingalev I.V.1, Orlov K.G.
1, Mingalev V.S.
1*, Chechetkin V.M.
2 , Mingalev O.V.
1 ................................................ 162
UPDATING 'CLASSICAL-PHYSICS': EXPERIMENTAL PROOF OF BOTH NON-EXISTENCE
OF EMPTY SPACE PHOTONS MOVING THROUGH IT ............................................................. 163
K. Mocnik ........................................................................................................................................................... 163
NEW EVIDENCE OF SOLAR INFLUENCE ON CLIMATE OF NORTH ATLANTIC AND
NORTHERN FENNOSCANDIA ......................................................................................................... 164
Ogurtsov M.G.1,2
, 2 Jungner H.3 .......................................................................................................................... 164
TWO TYPES OF THE MAGNETOSPHERE RESPONSE TO THE INTERACTION WITH
INTERPLANETARY SHOCKS IN THE GEOMAGNETIC PULSATIONS PSC .......................... 165
Parkhomov V.A.1, Yahnin A.G.
2, Borodkova N.L.
3, Tsegmed B.
4, Tero Raita
5,
Khomutov S.Y.
6, Pashinin S.Y.
7,
Chilikin V.E.1, Mochalov A.A.
2 ............................................................................................................................ 165
LOCALIZATION OF IONOSPHERE SOURCES OF HIGH-LATITUDE GEOMAGNETIC
PULSATIONS IN 2D FIELD DISTRIBUTIONS ............................................................................. 166
Petlenko A.V.1 .................................................................................................................................................... 166
PITCH-ANGLE DIFFUSION OF ENERGETIC PROTONS UPON THEIR INTERACTION
WITH EMIC WAVES: COMPARISON OF THEMIS DATA ON WAVE SPECTRA AND
ENERGETIC PARTICLES .................................................................................................................. 166
Popova T.A.1, Lyubchich A.A.
1, Demekhov A.G.
1,2, Yahnin A.G.
1 ........................................................................ 166
THE LATITUDE AND LONGITUDE DISTRIBUTIONS OF COSMIC RAY CUTOFF
VARIATIONS DURING THE MAIN PHASE OF THE MAGNETIC STORM IN NOVEMBER
2003 ...................................................................................................................................................... 167
Ptitsyna N.G., Demina I.M., Danilova O.A., Tyasto M.I. ..................................................................................... 167
THE CONTRIBUTION OF THE EARTH'S MAIN MAGNETIC FIELD VARIATIONS TO
AURORAL ACTIVITY IN 1600-1909 ............................................................................................ 167
23
Ptitsyna N.G., Demina I.M., Tyasto M.I. ............................................................................................................. 167
DIURNAL VARIATIONS OF THE BOTTOM EDGE OF THE IONOSPHERE DURING THE
PROTON PRECIPITATIONS ON AND AFTER 29 SEPTEMBER, 1989 ................................. 168
G. F. Remenets 1, M. I. Suhovey
1 , V. A. Shishaev
2 ............................................................................................. 168
BALLOONING INSTABILITY OF COUPLED MHD MODES IN 2D MODEL OF THE
MAGNETOSPHERE ............................................................................................................................ 169
Rubtsov A.V.1, Mager P.N.
1, Klimushkin D.Yu.
1 .................................................................................................. 169
PC5 COMPRESSIONAL EVENT OBSERVED WITH THEMIS: SPATIO-TEMPORAL
STRUCTURE, WAVE-PARTICLE INTERACTIONS ..................................................................... 170
Rubtsov A.V.1, Agapitov O.V.
2, Mager P.N.
1, Klimushkin D.Yu.
1, Mager O.V.
1..................................................... 170
ALFVÉN WAVES AS A DRIVER FOR MAGNETOSPHERIC DYNAMICS ................................ 170
V. Semenov1, M. Kubyshkina
1, I. Kubyshkin
1, N. Erkaev
2,3, E. Gordeev
1, M. Shukhtina
1, V. Sergeev
1 ................. 170
DEPENDENCE OF ENERGETIC PROTON PRECIPITATION EQUATORWARD OF THE
ISOTROPY BOUNDARY ON GEOMAGNETIC ACTIVITY .......................................................... 171
N. V. Semenova1, T. A. Yahnina
1, A. G. Yahnin
1, and A. G. Demekhov
1, 2 ............................................................ 171
ADVANCES IN MAGNETOTAIL MONITORING DURING SUBSTORMS ............................... 171
Sergeev, V.A. 1
, N.A. Tsyganenko1
, E.I. Gordeev1, V.G. Merkin
2, M.I. Sitnov
2, V. Angelopoulos
3, A.V. Runov
3 ... 171
INNER MAGNETOSPHERE RECONFIGURATION DURING THE SUBSTORM GROWTH
PHASE ................................................................................................................................................... 172
M. A. Shukhtina 1, E. I. Gordeev
1, V. A. Sergeev
1 .............................................................................................. 172
RING CURRENT PROTON DYNAMICS DRIVEN BY WAVE-PARTICLE INTERACTIONS
DURING A NONSTORM PERIOD .................................................................................................... 173
Smolin S. V. ........................................................................................................................................................ 173
THE SIMPLE ANALYTICAL DESCRIPTION FOR RELATIVISTIC (>2 MEV) ELECTRON
FLUX AT GEOSYNCHRONOUS ORBIT .......................................................................................... 173
Smolin S. V. ........................................................................................................................................................ 173
GEOMAGNETIC DISTURBANCES WITH SUDDEN AND GRADUAL COMMENCEMENTS IN
1869-1954 ACCORDING TO OBSERVATORY DATA AND CATALOGS OF STORMS ....... 174
24
Sergey Sokolov1, Vadim Soldatov
1, Vladimir Koshelevsky
1 ................................................................................. 174
SPATIAL-TEMPORAL CHARACTERISTICS AND PHYSICAL NATURE OF THERMAL
ANOMALY DIAGNOSED BY THE EISCAT RADAR WITHIN THE DUSTED NIGHTSIDE
AURORAL DYNAMO LAYER ............................................................................................................ 175
E.E. Timofeev,1
S.L. Shalimov,2,3
M.K. Vallinkoski,4 J.Kangas
4 ............................................................................. 175
CRITERIA FOR VULNERABILITY OF POWER TRANSFORMERS ELECTRIC POWER
SYSTEMS WITH PERTURBATION OF COSMIC WEATHER .................................................... 176
Vahnina V.V., Kozub A.A. Dubinin M.V. .............................................................................................................. 176
MANIFESTATION OF 60-YEAR CLIMATIC CYCLE IN CORRELATION LINKS BETWEEN
SOLAR ACTIVITY AND THE LOWER ATMOSPHERE CIRCULATION .................................. 177
Veretenenko S.V., Ogurtsov M.G. ...................................................................................................................... 177
LONG-TERM NORTH-SOUTH ASYMMETRY OF THE SOLAR MAGNETIC FIELD ............ 177
Vokhmyanin M., Zolotova N., and D. Ponyavin .................................................................................................. 177
RECONSTRUCTION OF PARAMETERS OF THE SOLAR ACTIVITY IN XVII CENTURY .. 178
N. Zolotova1, M. Vokhmyanin
1 ........................................................................................................................... 178
VERIFICATION OF THE OMNI DATABASE USING PC INDEX................................................ 178
Vokhmyanin M.V., Stepanov N. A., Sergeev V. A ............................................................................................... 178
RELATIVISTIC ELECTRON PRECIPITATION AND GEOMAGNETIC ACTIVITY ................ 179
A. G. Yahnin, T. A. Yahnina, and N. V. Semenova ............................................................................................... 179
SIMULTANEOUS OBSERVATIONS OF EMIC AND VLF WAVES DURING MULTIPLE
MAGNETOSPHERE COMPRESSIONS ............................................................................................ 180
A.G. Yahnin1, J. Manninen
2, T. Raita
2, T.A. Yahnina
1, E.E. Titova
1, A.G. Demekhov
1,3 ......................................... 180
ACCELERATION OF COLD ION COMPONENT AT THE SEPARATRICES DURING
COLLISIONLESS MAGNETIC RECONNECTION. ......................................................................... 180
I. Zaitsev1, A. Divin
1, V. Semenov
1 .................................................................................................................... 180
TRIGGER REGIME OF THE MAGNETOSPHERE DYNAMICS IN THE SOLAR ACTIVITY
CYCLE .................................................................................................................................................... 181
25
O.D. Zotov1, B.I. Klain
2, N.A. Kurazhkovskaya
3 ................................................................................................... 181
26
SECTION EG. EXPLORATION AND ENVIRONMENTAL GEOPHYSICS
Conveners - Dr. N.Y.Bobrov, Dr. A.K.Saraev
Exploration geophysics
Engineering geophysics
Environmental geophysics
Integration of geophysical methods
STRUCTURE OF THE NORTHERN PART OF SOUTH-ONEGA SYNCLINE
BASING ON AMT, GRAVITY AND MAGNETOMETRY DATA
K.Antashchuk1, K.Stepanov
2, A.Saraev
1.
1 – Saint Petersburg State University, Institute of Earth sciences
2 – FSBI “VSEGEI”
South-Onega syncline is located in southern part of Palaeoproterozoic Onega structure; it mainly consists
of Low Proterizoic terrigenous rocks which include dolerite Ropruchey sill. These rocks cover the
Archean basement.
Geophysical investigations have been carried out along the sub-latitude line of 58 km length in order to
clarify the geological structure of the syncline. The distance between AMT stations was 300-500 m;
between magnetometry and gravity points – 50 m and 100 m correspondingly. AMT soundings were done
using remote reference technique in the frequency band 0.1-1000 Hz.
An area of 5 km length has been detected where the anomalies of TM impedance phases are observed.
They exceed the 0-90 о quadrant at frequencies lower than 10 Hz. The mathematical modeling using two
types of synthetic models has been realized in order to explain this phenomenon. First model included
various blocks with electrical resistivity anisotropy; the modeling procedure was occurring in the
framework of 2D media. It has been shown that such anisotropy model could not cause the observed
anomalous impedance phase.
The second type of models, based on a-priory geological data of the Onega area, included two regional
and one local conductive bodies. The results of 3D modeling have shown that this type of models can
cause the anomalous impedance phases. Then, the model which matches best the obtained AMT response
has been created. The modeling results were used for further AMT data inversion.
The geoelectric section obtained according to 2D inversion of AMT data was used for set of polygons
configuration and further gravity data modeling. Density values for each polygon were choosing
according to known rocks physical properties. Basing on modeling results of magnetic survey both high-
magnetized rocks in the western part of investigation area and dolerites of Ropruchey sill in its central
part have been allocated.
Obtained geophysical data allowed us to construct the geological and geophysical models of investigated
area up to 10 km depth. They also helped us to clarify the structure of South-Onega syncline. The
thickness of protoplatform sedimentary cover is about 3 km. Graphitized zoneshave been detected in the
terrigenous deposits. Several blocks with different density values have been divided in the basement
structure.
27
BASIC 3-D GEOELECTRIC MODEL OF THE LITHOSPHERE OF BELARUS
Astapenko V.N., Dubanevich M.A.
Research and Production Centre for Geology, Akademika Kuprevicha st. 7, 220141, Minsk, Belarus
Magnetotelluric sounding were fulfilled at 372 locations within the territory of Belarus and one-
dimensional inversion of effective curves of apparent resistivity was fulfilled. Effective curves are
invariants relatively to registration axis and moreover they reflect a complex pattern of the
electromagnetic field distribution within 3-D geologic medium. Three-dimensional geoelectric model of
the lithosphere within Belarus is represented by diagrams of the electric conductivity distribution at
depths of 5, 10, 15, 20, 30, 50, 70, 90, 120, 150, and 200 km.
The produced model shows a sufficient areal differentiation. The resistivity of lithospheric rocks in the
western part of Belarus belonging to the Fennoscandian block of the Earth’s crust is 1.5-2 orders higher
than in its eastern part within the Sarmatian block. Similar differentiation is related to processes of the
formation of depressions at the consolidated basement due to the tectonic activation happened during
Paleozoic time. Four high-resistivity blocks are distinguished within the Belarus-Baltic Granulate Belt
separated by zones with lower resistivity. Through-the-crust conducting zones were distinguished within
the Pripyat Trough and Orsha Depression caused by regional faults: Stokhod-Mogilev, Perga-Surozh and
Chashniki (in the northern part of Belarus) ones. In the eastern part of Belarus at all structural stages a
meridional zone of increased conductivity was observed, which probably is related to the Trans-European
Lineament Zone. At the North of Belarus the Polotsk-Kurzemian conducting zone was formed at the
middle and lower crust levels.
TRANSIENT ELECTROMAGNETIC SOUNDINGS OF MAGNETICALLY
VISCOUS ROCKS IN THE ZHAMANSHIN IMPACT CRATER
Bobrov N.Yu.
Saint-Petersburg State University
Magnetic viscosity most often caused by superparamagnetism (SPM) may significantly influence the
results of transient electromagnetic soundings, especially in the case of high resistivity of the rocks. This
effect manifests itself in slowly decaying transient response, so called “long tails” of sounding curves.
This effect is described, for example, for Siberian platform flood basalts (Stognii et al, 2010). SPM effect
occurs in rocks containing ultrafine grains of ferrimagnetic minerals. In well conducting rocks the signal
caused by the induction transient process prevails over that associated with magnetic viscosity. If the
latter is a subject of interest, one should reduce the size of sounding array (loop size). It is also established
(Kozhevnikov, Antonov, 2008) that the maximal manifestation of SPM effect can be observed with a
coincident-loop system.
Zhamanshin astrobleme is an impact structure (age about 900 ka) situated in the Irgiz district of
Kazakhstan, 300 kilometers north of the Aral Sea. In the spring of 2018 the field works have been carried
out inside Zhamanshin crater aimed at studying the magnetic properties of impact rocks. Magnetic
viscosity was one of the points of interest because previous studies found ferrimagnetic nanoparticles in
some local impact melts (Starunov et al., 2016). In the course of field works a set of TEM soundings was
performed at different points in the crater. TEM-FAST instrument was used with coincident square loops
of different size, from 6 to 50 meters.
28
It was established that allogeneic breccia dominating in the upper part of the section and terrigenous
sediments overlapping breccia are very conductive (resistivity – first Ohm·m), in agreement with
previous results of VES soundings (Dabizha et al, 1980). Nevertheless, an influence of magnetic viscosity
was detected at some points with the use of small (6 and 12 meters) loops. Maximal SPM effect was
observed in the eastern border of the crater where suevites are outcropping at the surface. Curves of
apparent resistivity obtained at this point with the loops of different size diverge at the late times, whereas
voltage curves approach the asymptote 1/t demonstrating the influence of magnetic viscosity. Static
magnetic susceptibility estimated for the near-surface layer is of order 10-4
SI. The magnetic mineral
responsible for SPM effect is not established yet, though magnetite seems the most probable candidate.
Substantial magnetic viscosity of suevites was then confirmed by laboratory measurements of impulse
magnetization response. Measurements were carried out with the help of a pulse induction system (two
multi-turn coaxial coils) and a TEM-FAST instrument. In the time range 30-3000 mks impulse responses
satisfy the power law 𝐸(𝑡)
𝐼= 𝑎 ∙ 𝑡−𝑏 with b value slightly different from unity, possibly indicating a
deviation of true relaxation time distribution from Frölich function (Kamnev et al., 2015).
The work was supported by the RFBR grant 18-05-00626.
References:
Dabizha, A.I., Florensky, P.V., Alyunina O.I., and Alyunin A.V. Geophysical Investigations of
Zhamanshin Crater, USSR. In Lunar and Planetary Science Conference, vol. 11, pp. 192-194. 1980.
Kamnev, Y., N.O. Kozhevnikov, A.Kazansky, and S.M. Stefanenko, 2015, Impulse response of viscous
remanent magnetization: Laboratory measurements by a pulse induction system. Russian Geology and
Geophysics, 56, 1642–1651.
Kozhevnikov, N.O., Antonov, E.Yu., 2008. The magnetic relaxation effect on TEM responses of a
uniform earth. Russian Geology and Geophysics, 49, 197–210.
Starunov, V.A., Kosterov, A.A., Sergienko, E.S., Kharitonskii, P.V. Magnetic properties of impact melts
from Zhamanshin astrobleme. Proceedings of the 11th Intl School and Conference “Problems of
Geocosmos”. Oct 03-07. 2016. St.Petersburg, Russia
Stognii, V.V., Kozhevnikov, N.O., Antonov, E.Yu., 2010. TEM surveys for magnetic viscosity of rocks
in situ. Russian Geology and Geophysics, 51, 1219–1226.
RECENT RESEARCH OF GEOPHYSICAL PARAMETERS OF THE
LITHOSPHERE PLATFORM REGIONS
Burakhovych T.K, Kushnir A.N., Tsvetkova T.A.
Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev
In the course of geophysical investigations of the last decades a widespread presence of seismic and
geoelectric inhomogeneities in the consolidated crust of continents was established. The main role in
formations of these inhomogeneities is played by fluids and deep fluid systems.
According data seismic tomography and Depth Seismic Sounding the fluid flows correspond to
subvertical column velocity with alternating of high and low velocities. The last associated with the
processes of stretching and compression density differentiation medium for passing fluid flow. These
processes form the structures that are fixed as electroconductive layers.
In the ancient platforms the areas of concentration of epicenters of seismic events are often lined up along
zones of anomalies of electric conductivity. One can suggest that their close spatial correlation is due to
the common nature of their formation. At the same time the absence of such correlation in other parts of
29
the ancient platforms tells us that nature of this correlation is not fully understood and requires further
studies.
As a result we obtained, that some of these anomalies are extended on thousands kilometers along
regional and interregional high conductivity structures and can be the result of geodynamic processes.
The similar correlation is observed at both American continents, Australia and within the European
continent.
In view of the fact that intra-plate earthquakes tend to zones of loosening of rock matter and the presence
of such zones is usually related to fluids and their effect on the physical properties of rock matter it is
possible to suggest that formation of a conducting layer and a wave-conductor in the Earth crust is
defined by the metamorphic processes of dehydration and hydration - release of water and carbon acid.
Migration of small amounts of fluids from upper mantle into consolidated crust also takes part in
formation of such inhomogeneities.
RESEARCHING OF PHYSICO-CHEMICAL PROPERTIES OF RESEVOIR
FLUIDS BY NMR-RELAXOMETRY METHOD
E.S.Chernova1, M.Y.Shumskayte
2
1 - Novosibirsk State University, Novosibirsk
2 - Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk
Nowadays the methods based on the phenomenon of nuclear magnetic resonance (NMR) are becoming
increasingly relevant in the petroleum industry. This method is used to evaluate the porosity and
permeability properties of reservoir rocks and to study the physicochemical properties of fluids which
saturate them.
The work is aimed at analyzing capabilities of the NMR-relaxometry method for evaluating the viscosity
and determining the group composition of oil containing fluids. Laboratory investigations were performed
on the NMR-relaxometer "MST-05" with frequency of 2.2 MHz and magnetic field 0.05 T. A series of
experiments was conducted on samples of liquid hydrocarbons from collector layers of some deposits in
Western Siberia, their physicochemical properties were evaluated and also the obtained data were
compared with the data of liquid chromatography.
The NMR-method is based on recording the attenuation/losses of macroscopic magnetization, which
arises from the precession of magnetic moments of hydrogen nuclei in an electromagnetic field. The main
result of the measurements is a relaxation curve, whose mathematical processing gives a distribution of
transverse relaxation T2 over time.
The possibility of determining the group composition is due to the fact that different groups of chemical
compounds (asphaltenes, tars, aromatics and saturated hydrocarbons) have different molecular mobility
and, therefore, are characterized by different relaxation times T2: the greater the mobility of molecules,
the longer the time T2, which characterized the fluid.
As a result of comparison of the obtained data with the results of geochemical methods, it is possible to
distinguish intervals of times T2, which are typical of various types of organic compounds, for example,
light oil have relaxation times T2 greater than 200 ms.
Laboratory NMR-researching of hydrocarbons are extremely important for determining their relaxation
characteristics and subsequent typification, which is necessary to improve the techniques of interpreting
the data of nuclear magnetic resonance logging.
30
Further research will be directed to studying the physical and chemical properties of water-oil emulsions
by NMR-relaxometry and dielectric spectroscopy methods and their complex interpretation. These
methods are mutually complementary and are promising for petrophysical and geochemical research.
The work was carried out with the financial support of the project RFBR 18-35-00112.
NEW MAGNETOTELLURIC STUDY OF THE DEEP STRUCTURE OF THE
SOUTH-WESTERN CRIMEA
Desyatov D.O.1, Pushkarev P.Yu.
1, Rokityansky I.I.
2, Stafeev A.N.
1, Yakovlev A.G.
1,3
1 – Lomonosov Moscow State University, Moscow, Russia
2 – Subbotin Institute of Geophysics, Kiev, Ukraine
3 – North-West Ltd., Moscow, Russia
We present the results of magnetotelluric soundings, performed in the Mountainous Crimea along the
profile Yalta-Novosyolovka. We consider methods of observation and processing of magnetotelluric data,
obtained in abundant industrial noise area. Results of data analysis and two-dimensional inversion are
described. In particular, electric conductivity anomaly, associated with the Predgorny (Piedmont) fault,
was revealed. Geological interpretation of the resistivity cross-section until 5 km depth is provided.
THE FEATURES OF DEAD BAND AMT SIGNAL IN CHUKOTKA REGION
E.Ermolin1, O.Ingerov
2, A.A.Yankilevich
3, N.N.Pokrovskaya
3, T.V.Davytkina
3, V.Melnikov
1
1 - GM-Service LTD
2 - Phoenix Geophysics LTD
3 - Saint-Petersburg Mining University
We analyze the amplitude spectra of the audiomagnetotelluric (AMT) natural-source signal. Special
attention is given to the signal in the frequency range from 1 kHz to 5 kHz known as "dead band". We
study the measurements of the base sites that were used during summer fieldwork in 2013, 2014 and 2017
in Chukotka Region (Russian Far East). The area is located above the Arctic Circle. As it has been
described by previous researchers, the stable signal in the dead band can be acquired only at nighttime.
We would like to point out that in the daytime the local maximum at 2.4 kHz frequency is observed
within the dead band in Chukotka. The 2.2 kHz and 2.6 kHz frequencies can be reconstructed by using
more than 3 hours of daytime data acquisition. These frequencies can be used as the ranging marks. These
ranging marks sometimes allow to reconstruct the AMT curve by using the relationship between the
amplitude and phase.
It is possible that the continuous registration of time series at high frequencies and improving the ways of
magnetic sensor installation will allow decreasing measurement length in the daytime and increasing data
quality in the dead band. For equipment, it is currently important to perform operative amplitude spectra
visualization immediately after performing measurements on the site.
31
THE WAY OF THE HOST MEDIUM INFLUENCE CORRECTION IN THE
EXPRESS-INTERPRETATION OF 2D MAGNETOVARIATIONAL
ANOMALIES
E.Ermolin1, O.Ingerov
2
1 «GM-Service» LTD
2 «Phoenix Geophysics» LTD
Earlier, the authors found out that by using the singular points on the cross-section of magnetovariational
(MVP) data, it is possible to quickly determine the parameters of the 2D anomalous object (Ingerov and
Ermolin 2010). The depth of the geometric center of the object (H) is defined as H = α• D + с (1). The
relative conductivity of the cross section (G) is defined as G = γ• Textr (2). In these two linear relations,
D is the distance between the singular points on the tipper magnitude pseudo-sections. Textr is the value
of the period of singular points. It is known that the host medium influences the morphology of the MVP
anomalies. In this paper, we propose a method for taking the influence of the host medium into account.
The task is solved by determining the coefficients α, c and γ. The determination of the values of the
coefficients is carried out in two stages. At the first stage, based on the results of the 1D inversion of the
TM mode of magnetotelluric data, a horizontally layered host medium is determined. The second stage
involves 2D modeling of the magnetovariational response functions. To determine the coefficients α and
c, the calculation is performed for 2 models with two different depths (H). G remains constant. To
determine the coefficient γ, the calculation is carried out for two models with different G (the depth H
remains constant). Since dependencies (1) and (2) are linear, four calculations are sufficient to determine
the coefficients.
DISTORTION OF LOCAL MAGNETOVARIATIONAL ANOMALIES BY
EFFECT OF REGIONAL STRUCTURES
E.Ermolin1, O.Ingerov
2
1 - GM-Service LTD
2 - Phoenix Geophysics LTD
We consider the influence of the host medium on the morphology of the magnetovariational (MVP)
anomaly of a local object with a relative conductivity of the section 10,000 Sm•m and 500 m depth.
Conclusions are based on mathematical modeling. As result of modeling results the following conclusions
are valid:
1. The host medium affects the morphology of the magnetovariational anomaly. The morphology of the
anomaly is primarily related to the parameters of the sedimentary cover.
2. If the local and regional anomaly can be visually separated, the presence of large remote regional
conductors in the studied area has a very weak effect on the shape of the anomaly from the local 2D
object.
3. The local magnetovariational anomaly, distorted by regional anomalies, can be isolated by simple
subtracting the regional constituent of the components of the Wiese matrix from the original field. The
32
local component determination is most correct when the anomalous object is removed from the regional
conductor at a distance greater than the depth up to upper edge of the anomalous object.
4. If the regional component is correctly taken into account, the methods of express interpretation of
magnetovariational data and inversion can be applied to the isolated anomalies. At the same time, it is
necessary to determine the parameters of the horizontally layered host medium and take the influence of
the host medium into account.
5. The local body appears on the AMT and MVP responses in different frequency bands.
ANALYSIS OF THE EFFECT OF ENVIRONMENTAL FACTORS ON THE
DISEASE INCIDENCE OF PETROZAVODSK RESIDENTS, BASED ON
EMERGENCY CALL DATA
Gerasimova А.А., Belashev B.Z., Krutskikh N.V.
Institute of Geology, Federal Research Centre, Karelian Research Centre, RAS, Petrozavodsk Russia
Environmental pollution, climatic characteristics and magnetic field perturbances are the factors that
affect the disease incidence of the population. Therefore, the aim of the present study is to analyze the
profiles of diseases and to assess the effect of geomagnetic field variations and pollution level on the
aggravation of diseases with examples from Petrozavodsk. The city is located in an auroral latitude zone
with frequent magnetic field variations, and its individual areas differ in geological conditions and
ecological situation.
The study was conducted using the data obtained by Petrozavodsk Geophysical Observatory at
Petrozavodsk State University, the geomagnetic activity index Кр , and the BSMP impersonified
emergency call database for Petrozavodsk, which is used to assess statistical information on disease
incidence. Pollution is evaluated from the data obtained during ecologo-geochemical soil studies in 2011.
Calculations of the distribution of emergency calls and environmental factors were made using the
MATLAB computer mathematics system.
The profiles of various groups of diseases were obtained and maps, showing their distribution in various
city zones, were compiled. Subdivision of patients into various groups with regard for their sex and age
shows the demographic characteristics of the population. Analysis of the time dependence of emergency
calls has shown that daily call trends for individual diagnoses indicate that they are affected by seasonal
factors. The time course of the number of calls for some of the diagnoses were found to contain the
components similar to the rotation periods of the Sun and the Moon.
The absence of the correlation of the daily emergency calls with the diagnosis “myocardial infarction”
and geomagnetic activity index Кр, values has initiated the studies which showed that the minimum
number of calls is consistent with the most common index values and deviations from it to one or another
side increase the number of calls. The maximum number of emergency calls is registered on the first day
after a magnetic storm.
Integrated analysis of the soil cover pollution level and the number of calls has revealed the dependence
of the growth of the various forms of diseases on environmental conditions. The closest correlations were
shown for the diseases of the cardio-vascular system and areas with high soil pollution levels. The
relationship of pollution and psychical diseases is less obvious.
33
THE EXPERIENCE OF LOW-ALTITUDE MAGNETIC SURVEY USING
UNMANNED COMPLEX GEOSCAN 401
Goglev D.A., D.J. Capstan, Tsirel V.S.
GEOSCAN
For many years, mankind has been trying to make a breakthrough in the development of technology. Such
terms as robot, drone, artificial intelligence are deeply entrenched in the consciousness of modern man.
Do we know for what we need all these innovations for? This article presents the experience of using
unmanned aerial vehicles in magnetic exploration.
Magnetic exploration is one of the oldest geophysical methods, without which almost no search for
minerals can do. For more than a dozen years, magnetic exploration is mainly carried out in two ways:
from the aircraft and in the pedestrian version. Both variants of magnetic exploration are quite expensive,
and pedestrian shooting is often impossible because of the difficult landscape conditions.
GEOSCAN group of companies, having studied this problem, decided to create an alternative version of
the magnetic survey. Being one of the leading developers of software and unmanned aerial systems and
understanding all the advantages of the UAV application, we have developed a quantum magnetometer
on rubidium vapors and installed On an unmanned aerial vehicle of the GEOSCAN 401 series. With a
flight range of 20 km with a magnetometer and an average speed of 36 km/h, the GEOSCAN Geophysics
complex greatly facilitates and accelerates the production of accurate magnetic data. The first test flights
confirmed the high efficiency of both the created magnetometer and the system as a whole. Thanks to the
achievements of the company in the field of construction of accurate maps of the area, it became possible
to perform magnetic survey at extremely low altitude with a detailed envelope of the terrain. The work,
which was first carried out in Yakutia for the needs of LLC “Neryungriheofizika” at the iron ore Deposit,
and then in southern Kazakhstan on the order of LLP “SPC”Geoken”, aimed at finding gold and
stratiform polymetallic mineralization, showed high convergence of materials with the previously carried
out on the same ground and air magnetic exploration sites. The average quadratic error in the works in
Kazakhstan exceeded all expectations and was less than 0.5 NT.
In July 2018, the specialists of GEOSCAN carried out commercial work in the TRANS-Baikal region,
near the village of Gazimur Plant. Over 10 days, more than 800 km of profiles were investigated to search
for gold epithermal mineralization. Thanks in advance created the map of the heights failed to carry out
work under the radar without a single contingency. The equipment has confirmed its high potential and
ease of use.
The main advantages of magnetic surveys using unmanned technologies GEOSCAN over the classical
methods of obtaining magnetic data is its high performance (up to 160 km per day), detail, much less
noise, economic efficiency, possibility of obtaining reliable data from areas inaccessible to survey by
other means.
Recently, an increasing number of companies are interested in new technologies – including geophysical
surveys using UAVs. According to forecasts, in the near foreseeable future, low-altitude magnetic survey
from an unmanned aerial vehicle will significantly displace ground photography and even replace it.
34
ON NECESSITY OF GEOLOGICAL ENVIRONMENT MODEL
COMPLICATION FOR MONITORING ITS STATE AND FORECAST ITS
STABILITY
Hachay O.1, Khachay O.
2, Khachay A.
2
1 – Institute of Geophysics UB RAS
2 – Ural Federal University
The most important result of geomechanical and geodynamic studies of the past century was the
discovery of a close relationship between global geodynamic and local geomechanical processes caused
by mining operations, especially in tectonically active zones. No less important result of the research was
the conclusion about the fundamental role of the block-hierarchical structure of rocks and massifs for
explaining the existence of a wide range of nonlinear geomechanical effects and the emergence of
complex self-organizing geosystems. Hierarchical structure is typical for many systems, especially for the
Earth's lithosphere, where more than 30 hierarchical levels from tectonic plates with a length of thousands
of kilometers to individual mineral grains of millimeter size were identified by geophysical studies. Thus,
the earth's crust is not a continuous medium, but a discrete block system and, like any synergetic discrete
ensemble, has hierarchical and self-similarity properties.
The processes of development of oil and gas fields are associated with the motion of multiphase
multicomponent media that are characterized by noneqiulibrium and non-linear rheological properties.
The real behavior of reservoir systems is determined by the complexity of the rheology of moving fluids
and the morphological structure of the porous medium, as well as by the variety of processes of
interaction between the liquid and the porous medium. Accounting for these factors is necessary for a
meaningful description of filtration processes due to the nonlinearity, non-equilibrium and heterogeneity
inherent in real systems. In this case, new synergetic effects are revealed (loss of stability with the
appearance of oscillations, the formation of ordered structures). This allows us to propose new methods
for monitoring and managing complex natural systems that are tuned to account for these phenomena.
Thus, the reservoir system from which to extract oil is also a complex dynamic hierarchical system.
When constructing a mathematical model of a real object, it is necessary to use, as a priori information,
active and passive monitoring data obtained during the current operation of the facility. Modeling
algorithms were constructed in the electromagnetic case for 3-D heterogeneities, in the seismic case for 2-
D heterogeneities for an arbitrary type of excitation source of an N-layer medium with a hierarchical
elastic inclusion located in the J-th layer. A new 2D modeling algorithm for sound diffraction on elastic
and porous saturated saturation of a hierarchical structure located in the J-layer of an N-layer elastic
medium was developed in the paper. Modeling algorithms were constructed in the acoustic case for 2-D
heterogeneity for an arbitrary type of excitation source of an N-layer medium with a separate hierarchical
anomalous density, strained and plastic inclusion located in the J-th layer. In the further paper, using the
method described early, an algorithm for modeling the acoustic field (longitudinal acoustic wave) has
been developed in the form of an iterative process for solving a direct problem for the case of three
hierarchical inclusions of l, m, s-ranks using 2D integral and integro-differential equations. The degree of
hierarchy of inclusions is determined by the values of their ranks, which can be different. Hierarchical
inclusions are located in different layers above each other: the upper abnormally plastic, the second fluid
saturated and the third anomalously dense. When constructing a complex seismic gravity model without
taking into account the anomalous influence of a stress-strain state inside a hierarchical inclusion, called
the pillow of the deposit, an analysis of the anomalous acoustic effect using data on the propagation of a
longitudinal wave shows that the influence of anomalous elastic parameters in the seismic model cannot
be neglected, since they affect on the values of the unknown anomalous densities. If these values are used
in constructing a density gravitational model without taking into account the effect of elastic parameters,
these density values will not reflect the material composition of the analyzed medium. When constructing
an anomalously strained geomechanical model without taking into account the anomalous influence of
35
density heterogeneities inside the hierarchical inclusion, which is the substrate for a two-phase deposit,
the values of the unknown anomalous elastic parameters that cause the anomalous stress state in the
pillow using data on propagation of the transverse wave will be determined incorrectly. These values of
the elastic parameters will not reflect the real stress state of the analyzed medium located above the fluid
containing deposit, which in turn is represented by a hierarchical multi-neighborhood environment. For
the first time, the proposed iterative algorithm for modeling a hierarchically complex two-phase medium
can be used to control the production of viscous oil in mine conditions and light oil in sub horizontal
wells.
NATURAL ULF PERTURBATIONS OF THE ELECTRIC FIELD IN COASTAL
ZONES
Ismagilov V.S., Kopytenko Yu.A.
SPbF IZMIRAN, St. Petersburg,
In 2016-2017 SPbF IZMIRAN conducted experiments on the study of ULF electromagnetic disturbances
on the coast of the Barents and Okhotsk sea. Data logging was performed by geophysical stations GI-
MTS-1 located on a coast near the water's edge and in remote points moved away from the coast at
hundred meters.
It was found that the resonance ULF variations of electric field arises in a narrow (~50-100 m) Barents
sea coastal zone. The variations have a good correlation with tides (~4.5 m height above zero sea level).
Frequencies of the variations change from 0.1 to 0.2 Hz during a tidal period. The effect was not observed
at other station situated at the coastal line and at remote station situated at ~700 m from the coast.
At a narrow zone of Okhotsk sea an effect of correlation of electric field variations during the sea tide
periods (~2.4 m height above zero sea level). In contrast to Barents sea experiment we observed intensity
amplification of electric field disturbances during the tides periods. These intensifications were observed
in a broad frequency range (F = 0.001 – 1 Hz). It was found also an intensification of the wideband
electric field disturbances during a periods when a wind velocity growth. The effect was observed only in
the narrow coastal zone. At remote stations the effect was weaker in 3-5 times.
We suppose that the observed phenomena are connected with the marine aerosol positive charges and the
coastal glyph.
DEEP MAGNETOTELLURIC SOUNDING OF THE NORTHERN PART OF
THE SCYTHIAN PLATE
Kushnir A.N.1, Bryashko N.V.
2
1 – Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev
2 – Institute of Geology, Kiev Natsonal Taras Shevchenko University
[email protected], [email protected]
Modern experimental researches on the study of the natural low-frequency electromagnetic field of the
Earth with the use of modern equipment, processing of their results based on universal program packages
and interpretation (including on a qualitative level) can provide detection of electric conductivity
36
anomalies and the research of the deep structure of the Earth's crust and mantle. The deepest point of the
MTS village Ridne (N 45.70; E 34.6
0) characterized by complex geological-tectonic structure and located
in the northern part of the Scythian Plate, in the Sivas through between the Chongar and Melitopol-
Novocaritsyn defective zones. The total longitudinal conductivity according to the literary sources at the
point Ridne is 700 S, while the isohypses of the surface of the Upper Cretaceous reach 1700 m.
The processing was performed according to the standard one-point evaluation method. As a result, the
curves of the apparent electrical resistance in the meridional and latitudinal directions ρxy, ρyx, impedance
Zxy, Zyx, and impedance phases φxy, φyx. The curve ρyx is characterized by a continuous rise in the level of
apparent electrical resistance and only reflects the value of total longitudinal conductivity of sedimentary
deposits, and only in the largest periods of 3000 - 5000s there is a decrease in the value ρa with the output
of the curve on global data. This indicates a lack of significant regional galvanic distortions of the curve.
The curve ρxy is characterized by an ascending branch of the sedimentary strata in the range of periods of
20 - 200 s and with the presence of a characteristic bend on 200 - 1000 s with a pronounced minimum in
the range 700 - 2000 s. The curve ρxy after 1000 s is an order lower than the transverse and does not reach
the level of global data.
As a result of qualitative interpretation of the deep curves of the MTS, a layer of elevated conductivity
with a total longitudinal conductivity about 3000 - 5000 S and a boundary of the upper edge at depths of
50 to 100 km was allocated. The total longitudinal conductivity of the sedimentary layer along the
ascending branches ρa reaches over 400 S. The results obtained in the point Ridne are in good agreement
with the results of research performed in previous studies.
MT/MV STUDIES OF THE KIROVOGRAD ANOMALY OF ELECTRIC
CONDUCTIVITY IN THE SOUTHERN OF THE DENIPER-DONETSK BASIN
SLOPE
Kushnir A.N., Burakhovych T.K, Ilyenko V.A.
Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev
According to the results of qualitative interpretation of the curves ρa for different periods and the values
of the total longitudinal conductivity of the upper layer of sedimentary deposits (Ssed) the profile can be
divided into three parts: the first (0-50 km) – starting point (4956.6°N, 03241.7°E) – values ρa for
different directions the measure lines (ρху, ρух) coincide and is in the range of values from 10 to 100
Ohm·m in almost the entire frequency range; The second (50‒110 km) – the values of ρху and ρух differ
for 1‒1,5 orders, ρху is on average equal to 1÷10 Ohm·m, while ρух is 10÷100 Ohm·m; The third (110‒
190 km) – final point (4918.66°N, 03459.7°E) – the value of ρa from 1 to 50 Ohm·m throughout the
frequency range increases with the increase of the period, the difference between ρху and ρух is observed
at periods greater than 100 s and is equal to one order.
The value of Ѕsed increases gradually in the east direction from 450 (DDB slope) to more than 1000 S
(axial part of DDB). However, the information on the integral electrical conductivity of the surface layer
Ѕsedob, obtained on the ascending line of the observed curves ρa, does not support this information. In the
first part of the profile Ѕsed and Ѕsedob almost coincide and equal to 450‒600 S, then in the interval from 50
to 110 km Ѕsedob the values correspond to 400‒500 S and almost twice low then Ѕsedob which equal 900 S,
and in the interval of more than 110 km Ѕsedob are twice as high as Ѕsed and equal to almost 2000 S.
The comparison of the behavior of the data Ѕsedob and ρa indicates the existence of the deep electrical
anomaly in the middle part of the profile and implies it in the eastern. The results of the qualitative
interpretation of the curves of the МТ showed that the minimum depths of the upper edge of the
conductor vary from 20-30 km in the southwest on the slope to the maximum values of 50 km in the axial
zone of the DDB.
37
The profile crosses the south-eastern part of Glydyntsivska area, which is characterized by the presence of
the core and mantle rock mix with a capacity of 2‒5 km that is the characteristic for oil and oil condensate
fields. In addition, fracturing and deconsolidation in the basement and consolidated crust at depths of 20‒
30 km, due to the large node of intersection of fault zones of different systems. Deep anomalies in
electrical conductivity can be explained by the penetration of the fluids from the crust and the mantle, and
they are an important source for all processes of oil and gas deposits formation.
DEEP ELECTRIC CONDUCTIVITY OF THE AVACHA-KORYAKSKIY
GROUP OF VOLCANOES, KAMCHATKA
Yu. F. Moroz1,2
, V.A. Loginov1
1Institute of Volcanology and Seismology FEB RAS, 683009, Petropavlovsk-Kamchatsky, Piip Blvd.
9
2Geological Institute SB RAS, 670047, Ulan-Ude, Sakhyanova 6a
e-mail: [email protected], [email protected]
Investigation of deep structure of the Avacha-Koryakskiy group of volcanoes in the vicinity of
Petropavlovsk-Kamchatsky is a vital task. In previous years scientists conducted various magnetotelluric
soundings and collected various data, but a large size and a narrow bandwidth of the equipment prevented
from detailed research of the electrical conductivity beneath the Avacha-Koryakskiy group of volcanoes.
In recent years, we have conducted 45 km magnetotelluric lateral sounding in increments of 0.5 to 2 km
from SW to NE using MTU-5A equipment with an extended range of periods and analyzed geoelectrical
setting. Test models allowed studying coast effect as well as terrain effect in MTS curve behaviour. A
deep geoelectrical section was created using inversion of longitudinal MTS curves within the TM-mode.
In order to improve the structure of electrical conductivity in the upper zones of the section, we used
transverse curves within the range of periods free from coast effect.
We created a 60-km-deep geoelectrical model. There is a well-marked sedimentary-igneous layer beneath
the Avacha-Koryakskiy group of volcanoes with lower resistivity to 5-10 Ohm m at the depths from the
first hundreds of metres to 2-5 km. Maximum thickness was revealed in Avacha graben, which is located
west of Avacha and Koryakskiy volcanoes. There is a marked crustal layer with an increased conductivity
in the south-western part of the profile between depths of 15-25 km connected with a subvertical
conductive deep zone. The deep part of the model includes subvertical conductive zones with resistivity
varying from the first ones to 10 Ohm m. An anomaly zone with the increased conductivity is adjacent to
the upper part of Avacha graben and extends as deep as 30 km. The second anomaly zone with the
increased conductivity with resistivity from the first ones to 10 Ohm m was revealed in depth range
between 10 and 40 km. It is connected with a sedimentary-igneous cover through a narrow conductive
channel. These deep anomalies are probably faults that include liquid fluids as hydrothermal solutions and
magmatic melts. Partial rock melting in fault zones is likely due to solutions incoming from the crustal
layer and creeping vadose waters, which substantially reduce the melting temperature of the lithospheric
rocks.
38
PECULIARITIES IN GEOELECTRICAL STRUCTURE OF KAMCHATKA
EAST COAST
Moroz Yu.F.1,2
, Samoylova O.M.1
1 – Institute of Volcanology and Seismology FEB RAS, Petropavlovsk-Kamchatsky,
2 – Geological Institute SB RAS, Ulan-Ude; Institute of Volcanology and Seismology FEB RAS,
Petropavlovsk-Kamchatsky.
The rock conductivity is important characteristic of the Earth’s interior thermodynamic properties.
Information about deep conductivity has been got in Kamchatka along two regional profiles using
magnetotelluric sounding (MTS) method. The first profile “Severny” stretches out on 350 km along
north-eastern Kamchatka coast from Ossora settlement to Tilichiki settlement. The second profile is
situated on the territory of south-eastern coast from Nicolaevka settlement to Khodutka bay. Geoelectrical
sections were obtained along the regional profiles to a depth of about 80 km. The identified anomalies of
electrical conductivity were compared with the data obtained by other geophysical methods (specifically,
the data on gravity and anomalous magnetic fields). The comparative analysis of the geoelectrical
sections shows that electrical conductivity changes gradually in the northeastern region, while the
structure of the southeastern region is represented by blocks differing in geoelectrical properties. The
conducting horizon of the lithosphere lies at different depths in different parts of East Kamchatka. Nature
of the conducting stratum is related to solutions of high mineralization. Heat flow at investigated areas
changes from 70 to 80 mV/m2. Such a high temperature causes regional metamorphism processes at the
depth of about 12 km which result in separation of the water. This water has a high dissolving power at
high temperature and pressure. This results in the formation of high mineralization solutions, decreasing
resistivity in the medium.
DEEP GEOPHYSICAL MODEL OF THE AREA BETWEEN SHANUCH
COPPER-NICKEL DEPOSIT AND AGINSKOYE GOLD DEPOSIT IN
KAMCHATKA
Moroz U.F., Ulybyshev I.S.
Institute of Volcanology and Seismology FEB RAS
Aginskoye gold and Shanuch copper-nickel deposits are located in different structural zones. The
Shanuch deposit is located in the Middle Massif of metamorphic rocks. The Aginskoye deposit is
dedicated to the area of joint of the massif with the volcanic zone. Study of a profile 55 kilometers length
between the deposits was made by method of magnetotelluric sounding. The observation step is irregular
- from 2 to 4 km. For a comprehensive analysis of geophysical data were used aeromagnetic and
gravimetric surveys of past years.
As a result of solving the inverse problem were revealed the main features of the deep structure of the
earth's crust and upper mantle. In the geoelectric section of the earth's crust are distinguished two blocks
with different electrical conductivities: the western and the eastern. The Western block is located in the
Middle Massif of metamorphic rocks, which are brought to the surface here, and is characterized by
increased electrical resistances. In magnetic and gravitational fields this region is characterized by weakly
perturbed negative relative anomalies of magnetic field and gravity. The eastern block of the earth's crust
39
is distinguished by the increased electrical conductivity of the sedimentary-volcanogenic cover associated
with the influence of a wide network of tectonic disturbances. The increase in the intensity and frequency
of the anomalies of the magnetic field and gravity is also associated with deep faults. This block is
confined to the area of articulation of the eastern edge of the massif with the volcanic zone.
In the lower part of the section, a relatively conductive layer is separated at depths of 30-60 km, which is
associated with the presence of mineralized solutions and igneous melts in it. Deep faults in the area of
the Aginskoye deposit can penetrate through the earth's crust to the lithospheric conducting layer, and
serve as channels through which the fluids rise to the upper horizons of the earth's crust. As a result of
cooling and reducing the pressure from the fluids, accumulations of minerals forming deposits of non-
ferrous and noble metals are formed. The Shanuch deposit, apparently, has a different nature. It is
confined to ancient intrusives, brought to the surface as a result of tectonic activity.
The work was carried out within the framework of the RFBR project No. 16-05-00059a, as well as on
projects of the Far East Region No. 16-I-1-012e, No. 15-I-2-008.
THE INFLUENCE OF THE DAILY TEMPERATURE ON RESISTIVITY OF
SULFIDE MINE TAILINGS
Osipova P.S., Olenchenko V.V., Bortnikova S.B., Yurkevich N.V.
Trofimuk Institute of Petroleum Geology and Geophysics SB RAS
Wastes from the enrichment of sulfide ores are stored in dumps or tailings. High concentrations of metals
(Fe. Zn, Cu, Pb, Ag and Au) accumulated during storage, so such objects can considering as “technogenic
deposit” [1]. Ores are susceptible to hypergene changes under the influence of outside temperature.
Technology of secondary processing of mine tailings will depend on the degree of hypergene
transformation.
Daily variations of outside atmospheric parameters lead to a change in the natural electrical fields and
resistivity (ρ) [2]. The temporal dynamics of geoelectrical fields are often observed on ore deposits [3].
The temporal changes of geolelectrical properties that occur during the hypergene transformations of
technologene systems was the object of our study. The main purpose of this work is to determine the
nature and causes of the variation in the resistivity of the waste material during the day.
The study area is the tailings dump formed during the mining of the Beloklyuch deposit (Kemerovo
region). Gold was extracted from the upper parts of the ore bodies by cyanidation in the 1930-s years of
the last century. The structure, morphology, mineral composition of the ore bodies, the sequence of
mineral formation have been studied and described by many researchers [4].
The Electrical resistivity tomography (ERT) is most often used among geophysical methods to study the
mine tailings [5, 6]. Measurements were conducted by micro-electrotomography method on the surface of
the tailing. The sequence of connecting the electrodes corresponded to a dipole-dipole array. The length
of the profile is 9.1 m, the depth of the survey is up to 1.5 m. The measurements of rhe resistivity were
carried out every hour during the period of 24 hours. We determined the temperature of the tailings by a
probe at a depth of 0.1 m in the middle of the profile.
The geoelectric section of the tailing has zones of reduced and elevated resistivity according to the ERT
data. The anomalies of high resistivity correspond to the materials, which was changed as a result of
hypergenesis. Regular dynamics of ρ during the day on the graphs of electrical profiling refers to the
areas of increased resistivity. The daily temperature variation of the tailings and its ρ showed a strong
inverse correlation (K=-0.97). As the temperature of the tailings decreases, the resistivity increases, and
vice versa. We attribute this effect to the change in the conductivity of the pore solution. This dependence
40
is expressed by an exponential law, which is confirmed by other works [7, 8]. We conclude that the air
temperature is the main physical factor of the resistivity dynamics in tailing subsurface section.
Thus, the resistivity of the tailings depends on the outside temperature. Maximum changes are noted in
the zones of intensively altered rocks because of hypergenesis. This feature can be used as a criterion for
determining the degree of mine tailings transformation.
References:
1. Yurkevich N. V, i dr. Ocenka sovremennogo sostojanija hvostohranilishha zolotorudnogo
proizvodstva: cennye i toksichnye komponenty //Interjekspo Geo-Sibir'. – 2017. – T. 2. – . 4. – S. 113-
117.
2. Balasanjan S. Ju. Dinamicheskaja geoelektrika. Novosibirsk: Nauka, 1990. – 232 s.
3. Avgulevich D. L. Issledovanie menjajishhihsja vo vremeni estestvennyh jelektricheskih polej Zemli s
cel`ju vyjavlenija zakonomernostej ih formirovanija I sovershenstvovanija metoda estestvennogo
jelektricheskogo polja: dis. Na soiskanie uchenoj stepeni kand. Geol.-min. nauk: dis. – Irkutsk: dis. Kand.
Geol.-mineralog. Nauk, 2003.
4. Distanov Je. G. Kolchedanno-polimetallicheskie mestorozhdenija Sibiri. Novosibirsk, Nauka, 1977.
5. Bortnikova S. B. et al. Evidence of trace element emission during the combustion of sulfide-bearing
metallurgical slags //Applied geochemistry. – 2017. – T. 78. – C. 105-115.
6. Martínez-Pagán P.et al. Electrical resistivity imaging revealed the spatial properties of mine tailing
ponds in the Sierra Minera of Southeast Spain //Journal of Environmental & Engineering Geophysics. –
2009. – T. 14. – .2. – C. 63-76.
7. Besson, A., Cousin, I., Dorigny, A., Dabas, M., King, D., 2008. The temperature correction for the
electrical resistivity measurements in undisturbed soil samples: analysis of the existing conversion models
and proposal of a new model. Soil Sci. 173 (10), 707–720.
8. Ma R. et al. Comparing temperature correction models for soil electrical conductivity measurements
//Precision Agriculture. - 2011. – T. 12. – . 1. – C. 55-66.
ABOUT MEASUREMENT OF VERTICAL COMPONENT OF ELECTRIC
FIELD AT MAGNETOTELLURIC SOUNDING
Plotkin V.V., Mogilatov V.S.
Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, 630090 Russia
At magnetotelluric sounding (MTS) variations of five components of the electromagnetic field are usually
registered. At standard approach transfer functions are defined in an experiment namely ratios between
horizontal components of electric and magnetic fields. Deviations from the Tikhonov–Cagniard basic
model are defined by fifth registered component namely by vertical component of magnetic field.
Because of the complex geoelectric structure of the medium and in the presence of the MTS curve
distortions, there are difficulties at interpretation of data in practice. For increase in reliability of the
received results by the inversion and for bigger informational content of MTS, it is offer to carry out the
additional registration of vertical component of electric field in the medium. Comparison of calculated
values with experimental data on this component at the solution of the inversion task is very desirable. To
register variations of the vertical electric component, now the method of measurement of potential
difference arising on the vertical line shipped in the sea is applied. On the land for this purpose it is
necessary to drill new wells or use available ones, that is difficult. It is offered to apply the circular
electric dipole (CED) for registration of the vertical electric component. Now CED is successfully apply
as the emitter in methods of electromagnetic soundings. Its feature is use to excite only one TM-mode in
41
which electric field has vertical component in the layered medium. In practice, CED usually is implement
by eight long radial lines. Considering the specified feature, CED can be used and as the MTS receiver
for registration of variations of the field of TM-mode. Possibilities of its use at MTS are analyzed in this
work.
This work is supported by the Russian Science Foundation under grant 18-17-00095.
ABOUT THE ROLE OF THE HALL EFFECT AT MAGNETOTELLURIC
SOUNDING
Plotkin V.V., Mogilatov V.S.
Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, 630090 Russia
The containing rocks over deposits of oil and gas penetrated by a stream of hydrocarbon fluids represent
the semiconductor medium in which manifestation of Hall’s effect is possible. Interest in this
phenomenon has arisen by results of electromagnetic soundings with controlled sources in regions of
areas of hydrocarbons. The similar phenomena are possible also owing to impact of Earth’s magnetic
field on the currents caused in fluids at electromagnetic soundings of porous geological media. Here the
role of viscosity and conductivity is big. Their coefficients can be defined during the experiments. So far,
for the geological media the characteristic of microprocesses are known insufficiently, therefore it is
better to address an experiment. For its planning, it is possible to consider influence of the Earth’s
magnetic field, introducing Hall’s conductivity tensor. In the anisotropic medium, the field splits to the
components differing in coefficients of attenuation and phase speed – normal modes. The difference of
modes connected with its polarizations and the direction of rotation of a vector of the field, in one mode
the field rotates clockwise, in the second against. For physical reasons clearly that due to Hall's effect the
response of the medium can be unequal in cases of excitation of the medium by only one of normal
waves. For detection of influence of the Hall’s effect in magnetotelluric sounding the method of the
polarizing analysis based on a data processing algorithm with division of a time spectrum of the MT-field
into spectra of normal modes with the right and left circular polarization is offered.
This work was executed by financial support of the Russian Foundation for Basic Research, grant 17-05-
00083.
INFLUENCE OF MOSCOW MEGACITY ON NEAR-SURFACE ELECTRIC
FIELD VARIATIONS
Riabova S.A., Spivak A.A.
Institute of Geospheres Dynamics of Russian Academy of Science
The construction and development of megacities can disrupt the natural regime of physical fields, which
negatively affects the environment and biological objects. In this vein, variations of the electric field in
the near-surface layer of the atmosphere in the Moscow region were considered. The capabilities of the
Geophysical Monitoring Center of Moscow created in 2014 at the Institute of Dynamics of the
Geospheres of the Russian Academy of Sciences allow to perform continuous registration of the electric
field in the near-surface layer of the atmosphere and to isolate disturbances of anthropogenic nature from
42
sources located in the megacity. In order to establish the influence of a megacity on the electric field
variation in the surface atmosphere, a comparative analysis of the data obtained at the Geophysical
Monitoring Center of Moscow and Geophysical Observatory Mikhnevo of the Institute of Geosphere
Dynamics, located 85 km south of Moscow outside the zone of megacity influence (coordinates 54.9595º
N; 37.7664ºE) is carried out. Under similar weather conditions, the amplitude and diurnal variations of
the electric field strength in Moscow and outside the zone of megacity influence are close. The passage of
atmospheric fronts, atmospheric precipitation leads to a change in the magnitude of the electric field.
Moreover, man-made sources in the form of fire have a significant effect on the magnitude of the electric
field. In particular, a strong fire in the north-east of Moscow (2015.12.10) with an area of ignition of
about 15 thousand m2 caused a significant local warming of the atmosphere, as a result of which powerful
variations in the electric field strength.
FEYNMAN CORRECTIVE ELECTRICAL FIELD
B.G. Sapozhnikov
Institute of Environmental Geoscience of the Russian Academy of Sciences (St Petersburg Division)
Full DC electric field is treated as a vector sum of the «retarded» and the «corrective» fields of Feynman
formula. It is demonstrated the ability to express «magnetic» field and «corrective» electrical fields,
accordingly, through single and double rotors of vortex «retarded» field. Examples of DC devices
(railgun, magnet) confirm the workability of electric field in contrast to magnetic. It is shown that the
principle of short-range interaction of the electric field is valid in the Ehrenberg-Siday-Aharonov-Bohm
experiment.
INFLUENCE OF DISPLACEMENT CURRENTS ON THE RESULTS OF
FREQUENCY SOUNDINGS ON THE EXAMPLE OF THE RESULTS OF THE
EXPERIMENT "KOVDOR 2015"
Shevtsov A.N.
Geological Institute KSC RAS, Apatity
This paper addresses the Kovdor-2015 Experiment involving frequency electromagnetic soundings of the
Archaean basement of the Earth's crust in the southwestern part of the Kola Peninsula. Eleven soundings
were carried out using two transmitting arrangements, 85 km apart. Each arrangement consisted of two
mutually orthogonal grounded electric dipoles of 1.5 km long. The distances between the source and the
receiver were 25 and 50 km. Interpretation of the results took into account the influence of displacement
currents and static distortions. The effect of displacement currents is observed at high frequencies (above
800 Hz for distances of 50 km for apparent curves of the resistivity of the horizontal components of the
magnetic and electric fields and above 1200 Hz for distances of 25 km). These curves differ from the
apparent resistivity curves for the impedance components and increase with increasing frequency, while
at the same time the apparent resistivity curves for the main impedance components continue to follow
the dependence of the earth conductivity on the depth. This influence depends on the values of the
resistivity and the distance from the source.
43
Thus, the joint interpretation of the apparent resistance curves for the impedance components and field
components within the framework of the quasi-stationary approximation in the upper part of the
geoelectric cross-section does not make sense. At the same time, the effect of displacement currents on
the apparent resistivity curves for field components depends not only on the resistivity (conductivity) of
the rocks but also on their dielectric permittivity.
THE SOLUTION OF THE 2-DIMENSIONAL INVERSE MESD PROBLEM ON
THE SELIVANOV-HIITOLA-SORTAVALA-SUISTAMO (NORTHERN
LADOGA)
Shevtsov A.N., Kolesnikov V.E.
Geological Institute KSC RAS, Apatity
To date, a large volume of MT-AMT research in the Northern Ladoga area has been completed. All of
them refer, mainly, to the problem of the deep structure of the Ladoga anomaly. But, the electrical
conductivity of rocks that come out close to the surface of the day, has been little studied. The main
reasons were complex terrain conditions and the extreme meandering of the coastline, and the poor
development of the road network. To compensate for the gap formed by the combined team of the
Geological Institute of the Kola Science Center of the Russian Academy of Sciences and the Institute of
Geology of the Karelian Research Center of the Russian Academy of Sciences in 2015 and 2017, electric
profiling with a direct current along the Hiytola-Syustamo profile was performed in conjunction with
AMT-MTZ. In this paper, we consider the results of measurements using the method of an external slided
dipole (MESD) with measurements of the total vector of the horizontal component of the electric field of
a dipole source at a constant current. The remote sensing is carried out along the profile at four distances
of 500 - 2000 m on both sides of the source dipole, with a pitch of 500 m, and the source dipole (length
from 395 to 517 m, an average of 480 m) moves along the profile in 4500 m steps. The length of the
profile along the straight line was 116 km and 125 km, taking into account the tortuosity of the road
network. Due to the inability to perform measurements within the city of Sortavala, 8 km are missed
(from 82 km to 90 km from the beginning of the profile - Hiytola settlement). The most pronounced
anomaly of low resistance at the distances 40-50 km profile from beginning, and in the depth of about 1.5
km from the surface. There are anomalies in the area of 52-56 km in the depth interval 500-1500 m. And
if the first - the brightest anomaly is characterized by immersion from east to west, then the second - a
narrower in the range of depths, falls from west to east. The assumption of the multilevel structure of the
Ladoga anomaly, which was earlier proposed by B.N. Klobukov, looks highly likely.
44
SEISMOACOUSTIC TOMOGRAPHY ON JET GROUTING
Shmurak Denis1, Shishkina Mary
2
1 – Geological Faculty of Lomonosov Moscow State University, department of seismometry and
geoacoustics
2 – The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS)
Interwell seismoacoustic tomography takes a special place amongst so called “hidden” methods
as In urban development. Interwell seismoacoustic tomography is a reliable and very informative method
for surveying geological environment. Fundamentally important features of this method are the
approximation of the source and receiver to the object under surveying, as well as the detachment from
the day surface, characterized by high heterogeneity, sometimes with the complexity of the relief, and a
high absorbing capacity, which has a huge influence on the waveform and the possibility of operation.
Interwell tomography have no competitors among other geophysical methods in situations where there is
no access to the relief surface, or it is difficult (surveying of soils under buildings, surveying in dense
housing); when it is required to have a high accuracy of the border fretting and to search for small
irregularities in size and contrasts (search for karst cavities at great depth).
In this paper several sophisticated niceties of interwell seismoacoustic tomography are illustrated
on examples of applying this method for control of quality of jet grouting. The jet grouting technique has
become very popular all over the world as a practical means for solving several geotechnical problems
and it is important to develop methods of controlling its quality.
2D MODELING OF AMT DATA ON THE LADOGA AND PECHENGA
STRUCTURES
Skorokhodov A.A.
Geological Institute KSC RAS, Apatity, Russia
The AMT (audio-magnetotellurics) method was applied to solve structural problems at western flank of
the Pechenga structure of electrical conductivity and at the Janisjarvy fault zone of the Ladoga anomaly.
The purpose of these studies was to determine the angle of inclination and depth of the conductors which
were found by DC methods. Analysis of the observed AMT data showed that objects can be
approximated by two-dimensional models.
To calculate the response of an AMT field, the finite difference method is used, implemented by I.L,
Vardanyants. During modeling, the influence of the inclination angles of the conductive layers, the depth
of their bedding and flattening, and the influence of the anisotropy of electrical conductivity were
established. Also, when selecting models, the TE-mode of the EM field (when an electric field is directed
along the homogeneity axis) was taken into account firstly, as is reflected by the deep distribution of
electrical conductivity. And only at the last, refining stages, TM-mode, which is subjected by the
influence of near-surface inhomogeneities, was taken into account.
The simulation results showed that the Janisjarvy anomaly is probably a local near-surface conductor. The
Pechenga structure on the western flank is an alternation of high contrast resistivity layers, steeply
dipping in the southwest and flattening at a depth of about 2 km.
45
ON THE NATURE OF THE LADOGA CONDUCTION ANOMALY -
GRAPHITES AND (OR) FLUIDS?
Zhamaletdinov A.A1,2
, Sokolova E.Yu.3,4
, LADOGA Working Group
1 – Saint-Petersburg Filial of IZMIRAN.
2 – Geologial inst. of KSC RAS, Apatity
3 - Schmidt Institute of Physics of the Earth, Russian Academy of Sciences (IPE RAS), Moscow
4 - All-Russian Research Geological Oil Institute (VNIGNI), Moscow
[email protected], [email protected]
The structure and nature of Ladoga anomaly has been the object of research for more than 40 years. In
recent years, significant progress has been made thanks to the synchronous MT-MV profiling carried out
by the LADOGA working group on the Vyborg-Suojärvi trace [Sokolova et al., 2016], as well as the
shallow DC profiling with the use of multi electrode installations in combination with AMT soundings
[Zhamaletdinov et al., 2018]. High electrical conductivity of the upper part of the section (up to 1-2 km)
has been explained by the presence of electronically-conductive sulfide and graphite-bearing rocks.
The most popular hypothesis about the nature of the deeper part of the anomaly (about 20 km) was a fluid
one, presented by B.N. Klabukov (2006). However, this treatment faces a whole series of contradictions
in the terms of petrology, rheology, information on the heat flux, etc. [Yardley & Valley, 1997;
Artemieva, Shulgin, 2015; Pavlenkova, 1996; Karakin et al., 2002]. The modern MT-MV sounding
experiment of the LADOGA group, made it possible to construct a new sufficiently resolved model of
Lake Ladoga anomaly resistivity cross-section. In this model the deep conductivity structure is
represented by a series of inhomogeneous conductive tectonic plates gently dipping to SW and interpreted
as a series of thrusts developed along the Early Proterozoic formations containing graphite in their
composition by [Mints, Sokolova et al., 2018]. At the same time, graphite plays the role of "lubricant",
which facilitates the slipping of Proterozoic metamorphic plates during accretion (thrusting) of to the
edge of the Karelian craton in the Svekofenian time and later.
LITHOSPERIC CURRENT SOURCES AND THEIR IMPACT ON POWER
GRIDS
Vakhnina V.V., Gorokhov I.V.
Togliatti State University
[email protected], [email protected]
Powerful current source in a sial zone of the Earth, which are formed near the seismic centre are known
for a long time [1-3]. The beginning of the earthquakes is accompanied by a complex of various powerful
electromagnetic phenomena [2-4]. The importance of the earthquakes prognostication is the reason why
almost all the researches of the lithospheric current sources are connected with the searching of the
earthquakes premonitory symptoms [3-5]. At the same time in the descriptions of the development of
major accidents at electrical power generating system objects some phenomena attributed to the
earthquakes premonitory symptoms and also the increasing of the reactive power consumption which is
typical for a quasi-currents occurring can be noticed [1]. For the first time ever an assumption about a
negative effect of the lithospheric current sources on the power generating sets and power transformers
work was discussed in the work [1], where it is shown that a quasi-current can be a prime cause of the
Sayano–Shushenskaya power station accident.
46
Detected impulses of the lithospheric current sources can last from several minutes to several hours and
sometimes even for several days [2,5]. It was discovered that the telluric current density and thus the
radial component of the electrical intensity at the Earthquake surface is decreasing in inverse proportion
to the cube of the distance to the lithospheric current sources. Generally, the powerful electricity
transmission line length is hundreds of kilometers, and that is why the lithospheric current sources can
affect only one object of power grid. The occurring of the lithospheric current sources nearby the solid
grounded neutral electrical substations can energize in PTW a quasi-current that is able to provide a core
saturation. Assessments showed that the danger for the power grid work can cause the lithospheric current
sources that are formed at a depth of not more than 20 km [6].
As the lithospheric current sources are connected to the seismic centre [3], the danger for the power grid
work can cause the earthquakes, which geocentre is at a depth of not more than 20 km. The earthquake
effect of such seismic centres may be negligible, but the influence of the lithospheric current sources can
lead to the malfunction of the powerful objects of the high-power station.
High-power stations and major substations are often placed nearby the major rivers. These river flow
along the fault lines, where the possibility of the seismic centres formation is high. As a result, a
considerable part of the major substations are posed at a risk of the lithospheric current sources influence.
1. Селемир, В.Д. О вероятных причинах и сценарии развития аварии на Саяно-Шешунской ГЭС;
монография/ В.Д. Селемир и [др.]. Тольятти, Изд-во ТГУ, 2015. – 66с.
2. Воробьев, А.А. Физические условия залегания и свойства глубинного вещества. Высокие
электрические поля в земных недрах / А.А. Воробьев. Томск: Изд-во ТГУ, 1975. – 298 с.
3. Сурков, В. В. Электромагнитные эффекты при землетрясениях и взрывах : монография / В.В.
Сурков. – М.: Изд-во МИФИ, 2000. – 237 с
4. Смирнов С.Э. Особенности отрицательных аномалий квазистатического электрического поля в
приземной атмосфере на Камчатке / С.Э. Смирнов // Геомагнетизм и аэрономия. - 2005. - Т. 45. -
2. - С. 282-287.
5. Соболев, Г.А. Физика землетрясений и предвестники/ Г.А. Соболев, А.В. Пономарев. М.:
Наука, 2003. - 268 с.
6. Вахнина, В.В. Источники квазипостоянных токов и их воздействие на функционирование
систем электроснабжения / В.В. Вахнина, В.В. Горохов, И.В. Горохов // Промышленная
энергетика. – 2016. – 5. – С. 12–18.
INVESTIGATION OF SIGNALS OF GEOACOUSTIC EMISSIONS AND
ELECTROMAGNETIC RADIATION IN EXPLORATION AND DEEP WELLS
Alexey Vdovin, Yurie Astrakhantsev, Nadejda Beloglasova and Evgenia Bajenova
Institute of geophysics UB RAS, Russian Federation
Study of fracture zones and rock crushing, the identification of tectonic disturbances is an important task
in the research of the tectonics of ore deposits. These zones are defined by a complex of geophysical
methods in wells. As a rule, they make it possible to judge about already formed zones of disturbance.
Research into the background geoacoustic emission (GAE) and natural electromagnetic radiation
(NEMR) in sections of deep wells has shown that the maximal signal levels of both geneses mostly
coincide spatially by their depths with intervals of higher fracturing of rocks.
In-well measurements in GAE and NEMR have certain peculiarities and restrictions. It should be noted
that a well proper has an influence on the appearance and evolution of fracturing in the massif of rocks.
The boring process causes a substantial increase in the density of defects in the near-well volume,
47
especially when fractured rocks are drilled. This is a favorable factor for emission intensity to be
increased in the sequel. Moreover, a well with broken rocks is a concentrator of both quasi-static and
variable stresses, which influence the initiation and development of fractures in the volume of the
medium.
For measurements, we used a program-apparatus complex developed in the Institute of Geophysics, Ural
Division, Russian Academy of Sciences, which enables simultaneous recording of GAE in three
frequency ranges (100-500, 500-5000 and 2500-5000 Hz) and NEMR at three frequencies (45, 80 and
120 kHz). The sampling cycle is two seconds for all sensors. At every single point, measurements are
carried out and consist of ten cycles.
An example of the allocation of intervals of fractured rocks can serve as measurements performed in the
Arakayevsky parametric well (Sverdlovsk region). The set of standard geophysical methods stands out
cavernous interval with low density properties at depths 1545-1910 m. On measurements of GAE and
NEMR it was established that this interval is dynamically active. This is technologically dangerous and in
the future, rock falls are possible.
In the Onega Parametric Well (Karelia), the contact of rock salt deposits with the granitoid massif at 2940
m depth was notable for GAE and NEMR anomalies. This contact is an interval of broken (fractured)
rocks differing by durability properties.
Simultaneous measurement in GAE and NEMR in wells when studying fractured rocks enable us to
obtain information on manifestation of deformation processes in fields with varied physical nature, and,
consequently, to determine zones of high tensosensitivity, favorable for monitoring of geodynamic
phenomena in the Earth’s crust.
This work was partially supported by the project UB RAS 18-5-5-52.
POSSIBILITIES OF THREE–COMPONENT GEOACOUSTIC LOGGING AT
HYDROCARBON DEPOSITS
Alexey Vdovin, Nadejda Beloglasova, Yurie Astrakhantsev and Evgenia Bajenova
Institute of geophysics UB RAS, Russian Federation
The geophysical method of oil-gas borehole investigation devised at the Institute of geophysics UB of
RAS studies characteristics of geoacoustic emission (GAE) over the frequency range of 0.1÷5 kHz which
displays peculiarities of fluid-gas dynamic processes in a volume of geological environment. More over:
1. The second displacement derivative (acceleration) of borehole walls’ vibrations is recorded.
2. The three-component system of orthogonal transducers-accelerometers in a protecting casing of a
borehole instrument with the diameter of 40-42 mm enabling to divide geoenvironment microvibrations
into three directions is applied.
3. Frequency composition of recorded geoacoustic signals is analyzed.
4. Values of measured and calculated parameters representing distribution of signal amplitudes according
to three components at four frequency bands are evaluated.
Three-component geoacoustic logging at hydrocarbon deposits solves the following problems:
Estimation of fluid saturation character at a qualitative level;
Detection of fluid flow outside and inside the casing string with division into fluid types;
Detection of fluid flow position in chambers of a cement ring with division into fluid types;
48
Detection of non-sealed points of borehole equipment;
Location of gas-water, gas-oil and water-oil contacts;
Study of inflow section in a perforated interval of casing string which determines the boundaries
of efficient intervals;
Detection of sections with high absorption of drilling fluid in an open shaft;
Test for leaks of the column (together with thermometry);
Detection of intervals of fluid movement in horizontal direction outside a casing string within
seams
Detection of industrial deposits;
Revelation of water-flooded intervals of a hydrocarbon deposit.
Transducers-accelerometers with relative coefficient of transverse conversion not more than 6% allow
confident division of signals into three directions. Transverse sensitivity of a transducer is determined by
its maximum sensitivity to oscillations in a direction perpendicular to its main axis that is parallel to the
surface where it is placed.
The equipment has sensitivity that enables to record an acoustic response of geoenvironment to
deformations in the order of 10-8 – 10-11 m. Geoacoustic signals in sedimentary rocks are recorded by
three orthogonal transducers-accelerometers of PVT type (piezoelectric vibromeasuring transducer).
Transducers with coefficients of conversion not less than 6-10 V*s2/mm are installed into a borehole
instrument. Amplitude level of signals at different frequency bands is presented in units of recorded
acceleration mm/s2. Small amplitude of geoenvironment microvibrations is an additional optimum
condition to divide signals from three directions. Thus, signals from three directions are fixed at preset
depth in a borehole which makes it possible to compare their amplitude at different frequency bands.
STATISTICAL RELATIONSHIPS BETWEEN VARIATIONS OF THE
GEOMAGNETIC FIELD, AURORAL ELECTROJET, AND GEOMAGNE-
TICALLY INDUCED CURRENTS
A.V. Vorobev1, V.A. Pilipenko
2,3, Ya.A. Sakharov
4, V.N. Selivanov
5
1 – Ufa State Aviation Technical University, Ufa
2 – Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow
3 – Geophysical Center of the Russian Academy of Sciences, Moscow
4 – Polar Geophysical Institute of the Russian Academy of Sciences, Apatity
5 – Center for Physical and Technical Problems of Energy of the North, Russian Academy of
Sciences, Murmansk
One of the most significant manifestations of the space weather is the excitation of geomagnetically
induced current (GIC) in conducting technological systems during magnetic storms and substorms.
Modern power transmission networks with complex topology are in fact a giant antenna
electromagnetically coupled to the currents of the Earth's ionosphere. We examine statistical relationships
between variations of geomagnetic field, intensity of auroral electrojet, and GIC, using data from the
magnetometer array IMAGE and the records of GIC in the electric power line at Kola Peninsula. The GIC
49
intensity is found to have a highest correlation with the field time derivative dB/dt, whereas correlations
of GIC with dX/dt and dY/dt are nearly the same. The latter fact indicates on the quasi-isotropic character
of the magnetic field variability. Diurnal variations of geomagnetic field variability dB/dt and GIC
intensity have wide night maxima associated with the electrojet, and morning maxima presumably caused
by intense geomagnetic pulsations of the Pc5-Pi3 type. Statistical distributions of the probability density
of AE-index correspond to the generalized Pareto distribution, while distributions of magnetic
disturbance, variability |dB/dt|, and GIC better correspond to the log-normal distribution. On the basis of
constructed distributions the probabilities of extreme values of these parameters have been estimated. The
linear regression model has been developed which enables one to estimate the GIC magnitude from a
current value of the time derivative of geomagnetic field or AE-index.
This study is supported by the grant from the Russian Science Foundation No. 16-17-00121.
ABOUT THE INFLUENCE OF GEOMAGNETIC ACTIVITY ON
METROLOGICAL CHARACTERIS-TICS OF MAGNETIC INCLINOMETRIC
SYSTEMS
Vorobeva G.R., Vorobev A.V.
Ufa State Aviation Technical University, Ufa., Russia
It is known, that effective development of the Earth's interior is hardly possible without the use of modern
high-precision underground navigation systems. So, various kinds of inclinometric studies conducted on
the cable in oil and gas wells are one of the most important components of the whole process of drilling a
well. At the same time the sensitivity threshold of modern geophysical magnetosensitive information-
measuring systems (IMS) is comparable, and in many cases significantly lower than the amplitude range
of natural variations of the geomagnetic field (GMF) caused by geomagnetic activity (GMA). As a result,
for this and other reasons, specialists in geophysics, instrumentation, metrology and other related fields of
high technology manufacture are paying increasing attention to monitoring, forecasting, analysis and
minimizing additional errors that arise in the magnetosensitive equipment in operation during the GMA.
The paper is concerned with study of GMA (disturbed variations of GMF) influence on the metrological
characteristics of magnetic inclinometric information-measuring systems, widely used in geophysical
surveys in oil and gas wells. Also on the basis and in accordance with the standards, technical instructions
and normative documents in this branch of the national economy mathematical models are developed and
criteria are formulated for both qualitative and quantitative assessment of the degree of GMA impact on
metrological characteristics of magnetic inclinometer equipment. Also, special indices of GMA are
offered that allow to evaluate (including in the field conditions) the effect of this influence quickly and
with minimal effort, which obviously takes place both during calibration and verification, as well as
during operation of precision magnetic inclinometer equipment. The results of a numerical experiment on
the example of geomagnetic data (provided by the network of magnetic stations INTERMAGNET) on the
basis of models, criteria and indices of GMA described in the paper are presented and discussed.
50
SAMOYLOVSKY ISLAND - NEW INTERNATIONAL POLAR RESEARCH
STATION; FIVE YEARS UNDER OPERATION OF IPGG
Igor Yeltsov
IPGG SB RAS, Novosibirsk, Russia
Scientific research station “Samoylov Island” was built in 2010 by the decree of the Government of
Russian Federation in order to boost Arctic environment studies. Trofimuk institute of Petroleum
Geology and Geophysics (IPGG) of Siberian Branch of Russian Academy of Sciences (SB RAS) serves
as an operator of the station since 2012. Since 2013, the station operates in a full-year regime. It is
equipped with a set of modern scientific instruments and tools, which are required in different fields of
research (bio- and geochemistry, geophysics, climatic studies, hydrology, etc.). Speaking of
accommodation, the station provides very high level of comfort, standing in a row with best world
analogues.
Siberian Branch of RAS (SB RAS) together with Far East Branch of RAS, Arctic and Antarctic Research
Institute of Russian meteorological service (AARI), North-East Federal University, Alfred Wegener
Institute of Polar and Marine Research (AWI) and a number of other partners develops a joint Arctic
research program “Integrated Studies of the state and evolution of Siberian Arctic environment”. The
main goal of the program is to organize and perform a multidisciplinary research in the following
directions: geocryology (permafrost research); paleogeography; climate and paleoclimate; hydrology and
hydrobiology; geomorphology and quaternary geology; soil science, microbiology and gas emission from
permafrost soils; geophysics and zoology and biology as well.
Scientists from IPGG SB RAS has made a large input into permafrost studies in Lena Delta using a set of
geophysical methods: aerial imaging, magnetic measurements, electrical resistivity tomography
electromagnetic imaging, thermal monitoring etc.
Annual expedition on Samoylovsky island, performed by a joint field party from the Institute of
Petroleum Geology and Geophysics and Novosibirsk State University is a good example of the
interdisciplinary approach towards the solution of the sophisticated task of Arctic research. This
expedition introduced modern geophysics and rich experience of Novosibirsk geologists, paleonthologists
and paleomagnethologists, botanicists and soil scientists to permafrost research in Lena Delta. A number
of interesting objects, common for Arctic region were studied: thermokarst lakes, alases, (drained basins
of thermokarst lakes), pingos, lake and channel taliks, erosional valleys, yedoma sediments, degrading
subsea permafrost and many others. Together with colleagues from other countries (Germany, Finland,
Canada, USA, Japan, Sweden and others) we work on data processing and interpretation as well as
publication. Scientists from Novosibirsk with their fruitful work raise the quality of Arctic research to the
new level. This is especially important in the country, where permafrost covers the major part of the
surface. It is safe to say, that this direction of studies is going to be dominating for the next 50 years.
51
JOINT INTERPRETATION OF GEOPHYSICAL AND GEOCHEMICAL
FIELDS BASED ON THEIR ANALYTICAL CONTINUATION DOWN.
Ermokhin Konstantin M1, Zhdanova Ludmila A.
2
1 - Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation of the
Russian Academy of Sciences, St.-Petersburg Filial (SPbF IZMIRAN),
2 - NPP “Analytical Geophysics”, St. Petersburg.
A joint (complex) interpretation of data from various geophysical methods is significantly more reliable
than a separate method. As a rule, it is based on the assumption of the existence of any correlation fields
or physical parameters, therefore almost all these methods are based on the apparatus of mathematical
statistics.
The existence of regression dependencies between the physical properties of rocks is often a debatable
issue. In separate ore or hydrocarbon provinces, such local connections are most often not in doubt, and
reliance on reference objects is justified.
At the same time, there are no common global regular relationships between physical parameters and
fields. This was repeatedly noted by many researchers.
One of the possible ways of supplementing existing methods of integration is the application of the
method of analytic continuation of the fields observed on the surface of the fields down towards their
sources.
The universality of this approach is based on the generality of the description of fields used in geophysics
and geochemistry by partial differential equations of the second order. The commonality of all of them is
that they allow an analytical solution.Analyticity is understood in the sense of Weierstrass: the possibility
of their representation by power series in space variables, according to the Gauchy-Kovalevskaya
theorem.
Usually an analytical continuation is said about potential fields (gravitational, magnetic, DC field). In this
case, the methods rely heavily on solutions of the Laplace equation. This significantly reduces the scope
of the method, which is already limited in view of the decay of the field at the depth of the singular point
closest to the surface.
We have developed a universal method of analytic continuation - ACCF (analytic continuation by
continued fractions). It is based on the transformation of power series into continued fractions. Since the
real fields have singularities in the source domain, they can not be adequately described by linear
constructions that do not turn to infinity in the final domain of the solution search. And since a continued
fraction is a rational function, the zeros of its denominator turn out to be poles of the investigated field
function in the lower half-space, which coincide with its sources.
Separately, it should be noted geochemical fields, which are described by the diffusion equation, whose
solutions do not satisfy the conditions of the Gauchy-Kovalevskaya theorem. But since geochemical
processes of formation of deposits occur on a geological time scale, in fact, within the limits of 50-100
years, they can be considered stationary, i.e. satisfying the Poisson-Laplace equation. Therefore, the
ACCF method is quite applicable to geochemical fields.
The complexification is carried out on the basis of a comparison of the depth, location and configuration
of the sources of the various fields. The coincidence of these parameters for two or more methods
significantly increases the reliability of the results of the interpretation of geophysical and geochemical
research data up to direct prospecting of deposits of ores and hydrocarbons.
52
EXPERIMENTAL VERIFICATION OF METHOD FOR MEASURING THE
EFFECTS OF INDUCED POLARIZATION OF DEEP OBJECTS IN NATURAL
ELECTROMAGNETIC FIELDS
Ermokhin K.M., Kopytenko Yu.A., Petrishchev M.S., Sergushin P.A.
Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation of the Russian
Academy of Sciences, St.-Petersburg Branch (SPbF IZMIRAN)
Interest in measuring the parameters of the induced polarization with the use of natural electromagnetic
fields has recently increased. Due to the fact that the depth of the induced polarization (IP) method
(caused by polarization) when using generator sets (artificial field excitation) is limited of 300-500 m.
The depth of investigation increases substantially when measuring natural electromagnetic fields. Such
depth is not enough for the oil and gas complex where hydrocarbon deposits are located at depths of 2-4
km.
Prospects for the IP method for direct searches for hydrocarbon deposits (hydrocarbons) have been
proved by V.S. Moiseyev and V.M. Berezkin. The main search method of hydrocarbons is seismic
exploration that has the efficiency is 50-60%, with the addition of IP it increases to 90%.
The method developed by us consists in measuring the phase shift of a natural long-period signal in the
presence of IP. The vertical component of magnetic field is measured, which is not used in the
magnetotelluric sounding method (MTS). MTS method theory is assumed that the vertical component is
absent in the incident wave, and its presence is due only to telluric currents.
The proposed method is more technologically advanced for the solution of the hydrocarbon search
problem, however, only local objects are distinguished without the definition of the horizontal-layered
structure of the section. A special feature of the method is the synchronous measurement at several points
on the profile. However, since the object of the search is a deposit, this has little effect on the
effectiveness of geophysics. In addition, the absence of the need to measure electrical components
removes the complexity of their measurement and the influence of near-surface inhomogeneities.
The essence of the method reduces to the fact that the phase shift of the IP signal is practically
independent of frequency, and the phase shift due to induction is directly proportional to the frequency, as
shown by M.S. Zhdanov. The phase of the reference signal is difficult to determine, but with the aid of a
difference scheme one can obtain a result. The response of the medium to the k-th harmonic of the
polarizing field (telluric currents) consists in changing the amplitude and phase shift:2
( )in ipk k k
k
i tT
ka e
where in
k is the induction phase shift of the k-harmonic. -
ip
k phase
shift IP is directly proportional to the frequency, i.e. 2in
kkT
(μ-induction parameter), and
ip
k
does not depend on the frequency, i.e. ip
k .
Since the phase of the reference signal is undefined, but the measurements are synchronous, we use a
difference scheme. We calculate the phase shift of the response of the medium at two points 1 and 2 -
R1(t), R2 (t), not far from each other (of the order of 200-500 m), for some harmonic n. In synchronous
measurements, because the signal is in phase with the remote source of the polarizing field, the k-th
harmonic phase is the same. The difference in phase shift between points 1 and 2 is12
2 1 2 1( ) ( )n .
So we get a linear frequency function, with a constant component 2 1 and a linear coefficient
2 1 . Having constructed the curve 1i i i = 0 ... N along the profile (N is the number of
points on the profile) and integrating along the observation line, we get:
53
1
0
( )k
k j j
j
C
, i.e. in fact, a curve of induced polarization along the profile
up to a constant factor and an unknown term C (which is not used to construct the section by the
method of analytic continuation of the field to the sources). A geologically meaningful result was
obtained in 2017 in the process of tests on the Lehta structure in Karelia.
ON THE BOUNDARY BETWEEN THE BRITTLE AND DUCTILE PARTS OF
THE EARTH'S CRUST
Zhamaletdinov A.A.1,2
1 – Geological Institute KSC RAS, Apatity
2 – Saint-Petersbourg Branch of IZMIRAN
The deep CS AMT soundings indicate the boundary of sharp increasing of resistivity in the Earth's crust
at the depth of about 12 km . We named it as boundary of impermeability (BIP-zone). BIP zone divides
the Earth’s crust on the upper (brittle) and lower (ductile) parts. The upper part of the Earth crust of 10-12
km thickness is heterogeneous. Its heterogeneity is explained mainly by the wide spreading of sulfide and
carbon bearing crustal anomalies of electronically conductive nature and by presence of intermediate
conductive layer of dilatancy-diffusion nature (DD-layer) of fluidal nature having the regional spreading
on the Fennoscandian shield. The low crust of 20-30 km thickness is of high resistivity (105-106 Ohm∙m)
and is horizontally homogeneous. It can be depicted by the “normal” electrical section obtained in frame
of FENICS experiment. It is named as compaction zone having semi-ductile properties. At the depth of
about 12 km the "BIP” zone coincides with the boundary of “irresistibility” (BIR zone), that has been met
in the Kola super deep well SG-3. Due to this reason (high worsening of drilling conditions) four
damages happened in four drilling shafts of SG-3. Compaction and increased viscosity of rocks at 12-th
km and deeper is explained by elimination of tangential stresses, existing in the upper crust. So, we
quantitatively have found an important rheological parameter, brittle-ductile transition zone (BDT - zone
after Moisio, 2005). Earlier that parameter has been estimated only qualitatively on the base of laboratory
study of rock properties at high P-T conditions and seismic data on location of the earth-quake epicenters.
EXPERIMENT "MURMAN-2018" ON THE STUDY OF THE DEEP
GEOELECTRIC BOUNDARIES IN THE EARTH'S CRUST WITH THE USE
OF DC AND INDUCTION SOUNDING METHODS
Zhamaletdinov AA1,2,3
, Shevtsov AN1, Skorokhodov AA
1,
Kolobov VV3, Ivonin V.V.
3
1 - Geological Institute KSC RAS, Apatity
2 - St. Petersburg Branch of IZMIRAN
3 - Center for Energy of the North KSC RAS, Apatity
54
The Murman-2018 experiment on the deep electromagnetic sounding with the use of natural and
controlled sources was carried out in June 2018 on the territory of Murmansky Archaean block. The study
of proposed boundary of high resistivity (the boundary of "impermeability") at a depth of about 10-15
km, from which the basement position of the upper part of the Earth’s crust is associated, was the main
objective of the Murman-2018 experiment. The soundings have been performed with the use of distance
and induction approaches. Car generator “Energia-4” with a capacity of 29 kW and two mutually
orthogonal grounded dipoles each of 1.5 km length were used as a controlled source for frequency
(CSAMT) and distance soundings. Distance soundings were performed in the stacking mode. Rectangular
different-polar signals in the "meander" mode were generated for that with a period of 0.25 s. Distance
soundings were implemented with a linear increasing of distances between the source and receiver with
the step of 5 km in the interval from 5 to 50-100 km. CSAMT soundings in complex with AMTS in
frequency band from 1 Hz to 1 kHz were performed over a sparse network at separate points of distance
soundings, mainly for to take into account static shift distortions. Static shift corrections were estimated
by means of comparison of CSAMT apparent resistivity curves obtained from the input impedance and
from the field of total horizontal magnetic field.
NEW DATA ON THE NATURE AND STRUCTURE OF THE LADOGA
ANOMALY FROM DC AND AMT RESEARCH
Zhamaletdinov A.A.1,2
, Shevtsov A.N. 2, Skorohodov A.A.
2, Kolesnikov V.Ye.
2, Nilov
M.Yu.3
1 – Saint-Petersbur Filial of IZMIRAN.
2 – Geologial inst. of KSC RAS, Apatity
3 - Institute of Geology of KarSC RAS, Petrozavodsk
Ladoga anomaly is a part of Ladoga-Bothnian zone (LBZ) with extansion of more then 1000 km . The
deep Ladoga anomaly has been firstly discovered in the late 70s by Ukrainian research team
(Rokityansky et al., 1981) with the use of magnetovariational method. The anomaly was interpreted as
conductive body at the depth of about 10 km. In 70-th and 80-th the anomaly was studied in Russia
(Vasin, 1988; Kovtun et al., 1984) and in Finland (Hielt, 1984; Pajunpaa, 1984; Adam et al., 1982). By
results of digital 2D modelling it appears as conductive body with the resistivity falling down up to 2-20
Ω∙m at the depth of 20-30 km (Vasin, Kovtun, Popov, 1993). The third stage of study was realized in
2013-2015 by means of integrated magnetotelluric and magnetovariational profiling [Sokolova et al.,
2017]. Each of three stages were completed by construction of geoelectrical models at the depth interval
of 10-30 km. In this presentation the fourth stage is presented, that has been done in 2015 and 2017 by
means of DC electrical profiling with multielectrode installations in complex with AMT soundings.
According to results of the fourth stage, an unambiguous conclusion was drawn on the connection of the
upper part of the Ladoga anomaly of 130 km width with electronically-conducting sulfide-carbonaceous
rocks up to the depth of 0.3 – 0.6 km. The nature of the lower part of anomaly at 10-30 km is connected
with graphite containing geological structures [Sokolova et al., 2017].
55
SECTION P. PALEOMAGNETISM AND ROCK MAGNETISM
Conveners - Dr. P.V. Kharitonskii, Dr. A.A. Kosterov, Dr. E.S. Sergienko
Paleomagnetic reconstructions
Paleointensity
Rock Magnetism as Physical Basis of Paleomagnetism
INFLUENCE OF STRESS’ MATRIX ON THE INCLUSION DEFORMATION
Afremov L.L., Anisimov S.V.
Far Eastern Federal Univerity, Vladivostok, Russia
In solving problems devoted to the study of the effect of mechanical stresses on magnetization processes of
rocks, it is assumed that the stresses applied to the sample and to ferromagnetic inclusion are equivalent.
Obviously, this assumption is based on the intuitive opinion that the stresses transmitted by the rock matrix to
the ferromagnetic grain are proportional to the stresses applied to the sample.
In this paper, an attempt is made to estimate the dependence of the distribution of mechanical stresses inside
the magnetic inclusion on the deformation of a nonmagnetic matrix.
All calculations are made in the framework of the following model:
The inclusion and the matrix are considered as elastic isotropic medium with elastic Lame constants 𝜆(𝑖𝑛),
𝜇(𝑖𝑛) и 𝜆(𝑒𝑥), 𝜇(𝑒𝑥), respectively.
A matrix of thickness 2𝑙 is bounded by two infinite planes that are subject to uniform compressive loads 𝑝
oriented along the axis Oz.
At a point considerably removed from the boundaries of the matrix, there is a spherical inclusion of the radius
𝑅.
We use the equations of equilibrium of the medium and Hooke's law:
𝜇
𝜆 + 𝜇∆𝑢 + ∇(∇, 𝑢) = 0, (1)
𝜎𝑖𝑘 = 𝜆휀𝑙𝑙𝛿𝑖𝑘 + 2𝜇휀𝑖𝑘 , 휀𝑖𝑘 =1
2(
𝜕𝑢𝑖
𝜕𝑥𝑘+
𝜕𝑢𝑘
𝜕𝑥𝑖), (2)
where 𝑢 = 𝑢𝑥 , 𝑢𝑦 , 𝑢𝑧 is a displacement vector, 𝛿𝑖𝑘 are symbols of Christoffel and Kronecker, 휀𝑖𝑘 stands for
an elastic strain tensor, 휀𝑙𝑙 = 𝑇𝑟(휀𝑖𝑘).
In the absence of inclusion, the matrix is subject to uniform stresses 𝑖𝑘 = −𝑝𝛿𝑖3𝛿𝑘3, which lead to
homogeneous deformation with displacement = 0,0, 𝑧 = −𝑝 (𝑧/𝑙). The presence of inclusion leads to a
change in the deformation of the matrix 𝑢 = + 𝑣(𝑒𝑥), where 𝑣(𝑒𝑥) is harmonic function vanishing at infinity.
We shall seek the displacement 𝑣 in the form of a superposition of centrally symmetric solutions (𝑟2, 𝑟, 1, 1/𝑟)
and their derivatives:
56
𝑣𝑖(𝑒𝑥)
= 𝑎 𝑖𝑘
𝜕
𝜕𝑥𝑘(
1
𝑟) + 𝑏 𝑘𝑙
𝜕3
𝜕𝑥𝑖𝜕𝑥𝑘𝜕𝑥𝑙(
1
𝑟) + 𝑐 𝑘𝑙
𝜕3
𝜕𝑥𝑖𝜕𝑥𝑘𝜕𝑥𝑙
(𝑟). (3)
Substituting (3) into (1) we obtain 𝑎 = −с (3𝜆 + 𝜇)/(𝜆 + 𝜇).
We construct the solution in the domain of inclusion 𝑣(𝑖𝑛) in such a way that 𝑣(𝑖𝑛)(𝑟 = 0) = 0:
𝑣𝑖(𝑖𝑛)
= 𝑑 𝑖𝑘
𝜕
𝜕𝑥𝑘
(𝑟) +1
2𝑓 𝑖𝑘
𝜕
𝜕𝑥𝑘
(𝑟2) = 𝑑 𝑖𝑘𝑛𝑘 𝑟 + 𝑓 𝑖𝑘𝑛𝑘 𝑟2, (4)
where 𝑖𝑘 = 𝜎𝑖𝑘(𝑒𝑥)
(𝑟 = 𝑅) are stresses at the matrix-inclusion boundary.
The following stress tensor corresponds to the displacement (4):
𝜎𝑖𝑘(𝑖𝑛)
= 2𝜇 [𝑓(𝑖𝑚𝑛𝑚𝑛𝑘+𝑘𝑚𝑛𝑚𝑛𝑖) 𝑟 + (𝑑 + 𝑓𝑟2)𝑖𝑘] + 𝜆[2𝑓𝑘𝑚𝑛𝑘𝑛𝑚𝑟 + (𝑑 + 𝑓𝑟2)𝑚𝑚] 𝛿𝑖𝑘 . (5)
Coefficients 𝑏, 𝑐, 𝑑 and 𝑓 can be obtained from the boundary conditions:
𝑣𝑖(𝑒𝑥)
= 𝑣𝑖(𝑖𝑛)
|𝑟=𝑅 , 𝜎𝑖𝑘(𝑒𝑥)
𝑛𝑘 = 𝜎𝑖𝑘(𝑖𝑛)
𝑛𝑘|𝑟=𝑅 . (6)
The solution to this problem makes it possible to determine the stress distribution in the inclusion.
PALEOMAGNETIC, ROCK-MAGNETIC AND GEOCHEMICAL
PROPERTIES OF THE RIPHEAN INTRUSIVE BODIES OF THE NORTHERN
PART OF THE BASHKIRIAN MEGAZONE (THE SOUTHERN URALS)
Anosova M.B.1, Latyshev A.V.
1,2, Khotylev A.O.
1
1 – Lomonosov Moscow State University, Geological Faculty, Moscow, Russia
2 – Schmidt Institute of the Physics of the Earth, Moscow, Russia
The studied objects are the intrusive bodies of the mafic composition and Berdyaush rapakivi pluton.
They are located in the core of the Bashkirian megazone (the Southern Urals). Their formation is related
to the Riphean stage of rift magmatism on the East-European craton.
The Berdyaush pluton (consist of syenites and rapakivi granites) and host rocks are cut by dolerite dykes.
The U-Pb dating of the Berdyaush granites and syenites yielded the ages of about 1370 Ma (Ronkin. et al.
2005). For the dike we obtained age 1349 ± 11Ma. The host rocks are folded together with the granites of
the Berdyaush pluton, while dikes were not subjected to these deformations, we attribute dikes to a later
and more shallow stage of magmatic activity.
According to geochemical characteristics, incompatible elements contents, La/Yb ratio and TiO2
concentration increase from south to north, indicating the deeper magma source.
We also performed the paleomagnetic investigation of the dikes and obtained the new paleomagnetic pole
for the high-temperature component of remanence. The obtained pole is located between the published
poles for 1265 and 1458 Ma for the East European craton (Lubnina et al., 2009; Buchan et al., 2000).
Furthermore, we found MT component possibly of the Later Paleozoic age.
The measurements of the anisotropy of magnetic susceptibility demonstrate three types of the magnetic
fabric. About 50% of the studied objects demonstrate the N-type of the AMS ellipsoid, when the minimal
axis K3 is normal to the contact of intrusion and the other two axis lie in the dike plane. In this case we
were able to reconstruct the magma flow lineation.
The Berdyaush pluton is bounded by the Bakal-Satka regional fault of NE strike in the west and the dikes
related to the Berdyaush pluton demonstrate the shallow magma transport from the west to the east. As
57
the studied dikes are generally transverse to this fault, we assume that it acted as the long-lived magma
feeding zone, which controlled the emplacement of mafic dikes and the Berdyaush pluton itself in
Riphean.
Northward from the Berdyaush pluton dikes are parallel to the Bakal-Satka fault, while magnetic lineation
in sills generally has NE strike. Consequently, the emplacement of intrusions was controlled by a regional
extension zone parallel to the Bakal-Satka fault. Since the central part of the Riphean rift was located to
the south, we assume that the magma flowed in a northeast direction.
This work was supported by RFBR (project 17-05-01121).
References:
Buchan K.L., Mertanen S., Park R.G., Pesonen L.J., Elming S.-A., Abrahamsen N., Bylund G., 2000.
Comparising the drift of Laurentia and Baltica in the Proterozoic: the importance of key palaeomagnetic
poles. Tectoniphisics 319 (3), 167–198.
Lubnina N.V. East European craton in the Mesoproterozoic: new key paleomagnetic poles. Doklady
Earth Sciences, 2009. Vol. 428, 1, p. 1174-1178.
Ronkin Yu.L., Matukov D.I., Presnyakov S.L. et al. “In situ” U-Pb SHRIMP dating of the zircons from
the nepheline syenites of the Berdyaush pluton (the Southern Urals). Lithosphere, 2005. 1. P. 135-142.
MAGNETIC MINERALOGY OF SAMPLES WITH L-SHAPED ARAI-
NAGATA DIAGRAMS
Aphinogenova N.A., Smirnov M.A., Gribov S.K.
Geophysical Observatory "Borok" IPE RAS, Moscow
The Thellier experiments on paleointensity Banc determinations on the Armenian Middle Jurassic basalts
revealed a weird behavior of the Arai-Nagata (A-N) diagrams which expresses itself in a sharp drop in
NRM intensity when a sample is heated to about 400 °C accompanying by a very weak pTRM acquisition
in this temperature region. On contrary, a further increase in temperature leads to sudden change for the
sharp increase in pTRM acquisition with almost no NRM decrease creating L-shaped A-N diagrams.
Accordingly, the consecutive Msi(T) curves recorded in external field = 450 mT show some degree of
thermal instability with omnipresent drop (small or not so small) in Ms intensity after heating to 400 °C.
At the same time, a quick heating straight to 600 °C reveals only a phase with Tc 550 °C which is stable
to heating up to 700 °C. Thermodemagnetization of Mrs and ARM indicate similar drop in intensity of
both magnetizations by heating to 400 °C, that is, long before reaching Tc proving that the nature of sharp
drop in NRM cannot be explained simply by its partial destruction due to possible metamorphic
processes. As is shown by X-ray data, the samples contains initially a low-Ti oxidized TM grains which
undergo further single-phase oxidation (SPO) during thermal treatment. Note that heating powder
specimens already to 200 °C yields precipitation of some amount of hematite. So, the working
hypothesize is that the observed sharp decay in Mrs, NRM and ARM, when the heating temperature
approaches 400 °C, reflects the DS rearrangements because of appearance of cracks due to developing of
deep SPO phase following by generation of hematite inclusions (lamellae) due to onset of heterophase
oxidation. In its turn, the intensive growth of pTRM on the background of practically stopped NRM
decay at higher temperatures is most likely due to a decrease in effective sizes of TM grains with a
corresponding increase in the efficiency of acquiring pTRMs. Noteworthy that heating powder specimens
to 525 °C increases the content of hematite up to 20-50 % but still at least a half of the material displays
spinel structure with low cell parameter 0.832-0.835 nm which points to amazingly strong thermal
stability of remnants of highly oxidized TM regions.
58
CHARACTERISTICS OF THE MAGNETIC SUSCEPTIBILITY OF SPIN
GLASSES
Belokon V.I., Chibiryak E.V, Trofimov A.N, Dyachenko O.I.
Far Eastern Federal University, Vladivostok
The long-term relaxation of the magnetic moment of spin glasses can be one of the reasons for the
formation of a viscous magnetization of rocks, so studying its reaction to the inclusion of a weak
magnetic field is of undoubted interest. In this article, the magnetic susceptibility and specific heat of spin
glasses are investigated in the Ising model approximation using the random interaction field method [1].
Using known approximations [2] for a two-sublattice magnet, we can write the following system of
equations:
1
1
1
1 1 1 011 2 012 1
1
1tanh
2
B
B
mM H M H M H h dH
B kT
,
2
2
2
2 2 2 022 1 021 2
2
1tanh
2
B
B
mM H M H M H h dH
B kT
,
(1)
where m1 and m2 are the magnetic moments per atom in the first and second sublattices, respectively, h is
the external field, H011 and H022 are the fields from the atoms of the nearest neighbors for the first and
second sublattices, H012 and H021 determine the interaction of the atoms of different sublattices, M1 and
М2 are the relative magnetization per atom for the first and second sublattices, k is Boltzmann constant, Т
is the temperature, B1 and B2 are dispersions in the distribution function of the random fields of exchange
interaction [1].
Further consideration is limited to equivalent sublattices with competing interactions, for which the
results of computer simulation are known [3]. In this case, the equations for the moments of the
distribution function are as follows:
2 2 2
0 1 2 1 21 , 2 1 ,H K z K z B K z K z (2)
where K1 is the positive exchange integral, K2 is the modulus of the negative exchange integral, ν is the
relative fraction of atoms with the negative exchange interaction, z is number of the nearest neighbors.
Magnetic ordering is possible under the condition 0 / 1H B and if H0>0 - this is ferromagnetism , H0<0-
this is antiferromagnetism, 0 / 1H B - this is spin glass state.
The following relations are obtained:
The magnetic susceptibility of the spin glass (m1 m2=1, k=1) is determined by means the following
formulas
0 0
0 0
1 1tanh tanh
, 0 , 0 .
1 tanh 1 tanh
B B
B T B TH and H
H B H B
B T B T
(3)
The magnetic susceptibility of an antiferromagnet:
2 230 0
2
3 230 0 0
2
1tanh tanh tanh
,
1 tanh tanh tanh
H MB B B
B T T TBT
H H MB B B
B T T TBT
(4)
if T<TN (TN is the Neel temperature) and ϰ is determined by means formula (3) for T>TN.
The temperature dependence of the heat capacity is qualitatively the same as the known results of [3].
59
Acknowledgments. This work was financially supported by the State Program of the Ministry of
Education and Science of the Russian Federation 3.7383.2017/8.9.
References
V. Belokon, K. Nefedev, Distribution function for random interaction fields in disordered magnets: Spin
and macrospin glass, Journal of Experimental and Theoretical Physics 93 (1) (2001) 136-142.
V. Belokon, V. Kapitan, O. Dyachenko, The combination of the random interaction fields' method and
the bethe-peierls method for studying two-sublattice magnets, Journal of Magnetism and Magnetic
Materials 401 (2016) 651-655.
G. Petrakovsky, Spin glasses, Soros Educational Journal 7 (9) (2001) 83-89.
FIRST MAGNETOSTRATIGRAPHIC DATA ON THE UPPER CAMBRIAN OF
THE KEY SECTION OF THE CHOPKO RIVER (NW SIBERIAN PLATFORM)
Chmerev V.S., Pavlov V.E., Rudko D.V.
The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS)
Sedimentary (mainly carbonate) rocks of Cambrian age outcropping along the valley of the Chopko river
(Northwestern Siberia, Norilsk region) represent one of the most important key sections of the Upper
Cambrian of the Siberian platform. From the bottom to the top, this section, which thickness is about
1400 m, is divided into two parts: Chopko Formation and Tukalanda Formation. During the field season
2018 we have carried out the sampling of the upper part of the Chopko Fm and the whole Tukulanda Fm
for magnetostratigraphic studies. The main purpose of our study is to obtain new information on the
geomagnetic reversal frequency at the end of the Cambrian on the eve of the Lower Ordovician
superchron of reversed polarity (Moyero superchron). In this report we present the results of laboratory
studies of the gathered collection and estimate the prospects of the section for obtaining of the detailed
record of the changes of geomagnetic polarity during Late Cambrian.
THE FIRST PALEOMAGNETIC AND PETROMAGNETIC DATA OF TAKYR
DEPOSITS IN WEST TURKMENISTAN
Elena Degtyareva
The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS)
During past few decades, petromagnetic methods have been proven as an effective tool for analyzing
problems related to the climate and environmental changes. The aim of this study is to investigate the
perspectivity of petromagnetic characteristics of sedimentary sequences for the paleoclimatic
reconstructions on the territory of Central Asia (in particular, Turkmenistan) during the last five
millennia. The most promising methodology for these purposes is to investigate the evolution of the
coercivity spectra and thermal demagnetization curves along the sedimentary sequences. The proximate
complement to this method is to study the evolution of the other petromagnetic parameters (e.g. different
types of the magnetic susceptibility) through the sequence. The object of the present study is represented
as a 5-m thick sequence of Takyr deposits dated from the late Holocene, situated in Danata region
60
(Karadag piedmont, Western Turkmenistan). The peculiar feature of this sequence is the thin lamination
(varvs), where each layer represents one year of sedimentation. The dating of the sequence is based on the
superposition of annual varvs. According the varv chronology, the sequence has been deposited for
approximately 5000 years. We will present the preliminary paleomagnetic results, obtained from the pilot
batch of samples. The analysis of the demagnetization curves revealed two ferromagnetic components.
We estimated the contribution of the paramagnetic, superparamagnetic and ferromagnetic components to
the entire signal through the sequence. The analysis of this contribution gives the possibility to investigate
material input changes and the autigenic minerals occurrence. Studying the magnetic components
susceptibility variations gave us the possibility to reconstruct the depositional conditions. We also made
correlation between the petromagnetic properties and varv chronology along the sequence. Preliminary
results of the the comparison between the petromagnetic data and the sequence chronology and lithology
helped us to make conclusions on paleoclimatic conditions during the sequence deposition.
THE SUBDUCTION ZONES EFFECT ON THE STRUCTURE OF THE
SMALL-SCALE CURRENTS AT CORE-MANTLE BOUNDARY
Demina I., Gorshkova N., Ivanov S., Merkuryev S.
St-Petersburg Filial of Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio wave
Propagation (SPbF IZMIRAN)
In this paper, we examine the relationship between a kinematic of the small-scale current systems near the
core-mantle boundary and high-speed anomalies of seismic waves in the lowest mantle associated with
subduction zones. The macro model of the main geomagnetic field sources was early constructed by the
authors. Along with west drifting sources two sources were obtained, whose trajectories have a complex
shape. One of them is geographically located near the western coast of Canada (Canadian source) and the
second one is located in the vicinity of Sumatra (Sumatran source) Both areas are related to subduction
zones. Besides, these areas are characterized by existence of extensive coherent regions with increased
velocities of seismic waves in the lowest mantle. For the comparative analysis we used the S362ANI and
SAW642 models of the seismic velocities heterogeneities and smoothed trajectories of Canadian and
Sumatran sources.
It was found that the Canadian source trajectory, obtained for period from 1900 year to recent time,
passes along a high-speed anomaly in the lowest mantle. Unfortunately, only in some earlier epochs we
were able to obtain the parameters of this source. And only certain points of the trajectory around 1600
we were able to add to trace the development of the source. Despite this, the results obtained suggest that
the substance of the liquid core, mixing with the matter of the lowest mantle, rises along the lower mantle
channel and promotes its further increase. Also the source trajectory reflects the shape of the small-scale
channel in the lowest mantle.
As for the Sumatra source, it is localized and moves in the thickness of the liquid core on the majority of
the time interval considered. However, the western drift is completely absent for this source. Moreover,
its trajectory is characterized by series of loops with rising and lowering. The trajectory almost
completely passes near the powerful high-speed anomaly in the lowest mantle.
It can be assumed that in this subduction zone the volume of oceanic crust, subducted into the mantle
many millions of years ago, turned out to be sufficient for penetration into the liquid core, forming the
complex shape restrictions for free circulation of the core liquid. As a result the vortex currents can be
formed and effect on the geomagnetic field variations.
61
INTERPRETATION OF MAGNETIC ANOMALIES IN CONDITIONS OF
PRESENCE OF RESIDUAL MAGNETIZATION AND OTHER
COMPLICATIONS
Konstantin M. Ermokhin
Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation of the Russian
Academy of Sciences St.-Petersburg Filial (SPbF IZMIRAN), St.-Petersburg, Mendeleev line 1.
Traditionally, when interpreting the data of magnetic survey measurements it is assumed that all objects
are magnetized on the modern field. All existing methods of solving the inverse problem are based on this
assumption. This assumption is forced, because it is impossible to reliably determine the presence of
residual magnetization a priori. In addition, the degree of ambiguity in the solution of the inverse problem
is increased many times. At the same time, the theory of paleomagnetism is based on the study of the
parameters of the residual magnetization of rocks and it is based on the theory of mobilism, prevailing in
modern Geology. The assumption of a general magnetization in the modern field and the data of
paleomagnetism are in direct contradiction requiring some sort of permission.
It is also believed that at a depth of 20-30 km there is no magnetism, because the rocks are melted there.
But at the transition point Curie iron, for example, as the second most common metal in the earth's crust,
goes into a state of paramagnetic, rather than demagnetized at all. Moreover, according to the generalized
Curie-Weiss formula: ( ) /( ) ,c cT C T T T T , where χ is the magnetic susceptibility, T is the
temperature, Tc is the Curie point, C>0 and γ>0 are constant for each specific substance (rock). It turns
out that at great depths there can be local moving areas with almost infinite χ (at cT T ), creating large
magnetic anomalies on The earth's surface. There are experiments confirming this position, in particular
for metals such as Ti, Zr, W, Mo.
These circumstances reduce the degree of reliability of the results of traditional methods of interpretation
of magnetic survey data.
One of the possible ways to resolve the existing contradictions in the interpretation of magnetic data
could be a method of analytical continuation of the magnetic field in the direction of sources. It allows to
determine their depth, configuration and relative distribution of magnetization in section regardless of the
direction of magnetization (which is not really known). This makes it possible to abandon any a priori
assumptions about the objects of study and get a more adequate idea of the sources of magnetic
anomalies.
MAGNETIC PROPERTIES OF SOILS FROM THE VOLGA-KAMA FOREST-
STEPPE
L.A. Fattakhova, L.R. Kosareva, A.A. Shinkarev
Department of Geophysics and Geoinformation Technologies, Kazan Federal University, Kazan,
Russia
We study the magnetic properties of virgin forest-steppe soils which formed on original vertical uniform
unconsolidated parent material. In this work, profile samples of virgin dark-gray forest light loamy soil
developed on a Permian (Kazanian stage) siltstone and virgin leached medium-thick fat light-loam
62
chernozem developed on the Quaternary deluvial loam were used. Both soils are characterized by
accumulative type of magnetic susceptibility and its components. The accumulative type refers to a
profile where the maximum accumulation of substances takes place at the surface with a gradual fall in
their content with depth. The calculation of frequency-dependent magnetic susceptibility (F-factor) shows
that in studied soils F-factor reflect changes in their ferromagnetic fraction. In the humus part of the soil
profile magnetic materials are present predominantly as fine mineral particles, and their content in the
<2.5 µm fraction decreases toward the soil-forming rock. Estimates of relative contributions of dia - /
paramagnetic, superparamagnetic, and ferromagnetic components obtained from the coercive spectra
shows that the increase in the magnetic susceptibility in organogenic horizons of forest-steppe soils is due
to the contribution of the ferromagnetic component.
The work is performed according to the Russian Government Program of Competitive Growth of Kazan
Federal University.
TECTONIC AND GEOLOGICAL RESTRICTIONS ON DEVELOPING APWP
FOR NORTH EURASIAN PLATE IN PERMIAN TIME
Fedyukin I.V.
The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences
Based on paleomagnetic data, analyzed possible scenarios of the relative position of the Siberian Platform
and the European Platform ( during Permian time and drifting at the stage of consolidation in the structure
of the supercontinent Pangea are considered. Modern paleomagnetic data allow for developing reliable
APWP for Siberian and European platform. Comparison of the Siberian and European APWPs shows that
since Mesozoic time the both platforms were part of the North Eurasian tectonic plate (North part of
Pangea supercontinent). The plate was located in close to the modern coordinates and drifted with
clockwise rotation. Since early Jurassic time, the eastern part of the Siberian platform reached the North
Pole. During the Jurassic period, the rotation was maintained and by the end of the period the plate
occupied a sublatitudinal position. For the Permian period (since early Permian time to P-T boundary),
the relative position of the Siberian and European platforms can be described by the rotation of the
Siberian block relative to the European block clockwise by 46° around the Euler pole, located in the area
of the Northern Land (Severnaya Zemlya archipelago).
Such a mechanism of interaction between Siberian and European platforms has determined the structural
figure of deformations within the folded systems of the Arctic and Central Asian fold belt that have
survived to the present day. Probably, the problem of space in the subconsolidated crust of Western
Siberia, caused by the convergence of Siberian and European platforms, was realized through the
constriction of the structures of the mobile belt to the north and south along the systems of shear zones.
The research was supported by grant of the Government of the Russian Federation No. 14.Z50.31.0017.
63
ANALOGUE OF THE NEDUBROVO ANOMALOUS REMANENCE IN THE
ZHUKOV RAVINE SECTION, RUSSIAN BASIN: THE EVIDENCE FOR
UNUSUAL BEHAVIOR OF GEOMAGNETIC FIELD BEFORE PERMIAN-
TRIASSIC BOUNDARY
Fetisova A.M.1,2
, Veselovskiy R.V.1,2
, Mamontov D.A.1
1 – Geological department, Lomonosov Moscow State University, Moscow, Russia
2 – Schmidt Institute of Physics of the Earth RAS, Moscow, Russia
The Nedubrovo member of the Moscow sedimentary basin was firstly described by (Lozovsky et al.,
2001) and still is the subject of continuing disputes due to the uncertainty of its age. Numerous
determinations of fauna and flora allow to suggest the age of the Nedubrovo deposits as Upper Permian
(Arefiev et al., 2016, Lozovsky et al., 2016) or Lower Triassic (Lozovsky et al., 2017). Any stratigraphic
analogues of the Nedubrovo member have not been known. We present the results of complex
paleomagnetic and rock magnetic studies of the upper Nedubrovo horizons, which are outcropped in the
lower stream of the Kichmenga River, and compare them with the paleomagnetic data from Upper
Permian red beds from the Zhukov Ravine outcrop (Gorokhovets settl.), which were re-studied by our
team in 2018. The most important result is that we find the horizon with anomalous paleomagnetic
direction in the Upper Permian layers of the Zhukov Ravine section, which paleomagnetic direction is
consistent with anomalous one from the Nedubrovo outcrop, located 450 km to the NE. So, we have
found additional evidence for the existence of a period of significant and prolonged deviation of the
Earth's magnetic field configuration from the Geocentric Axial Dipole (GAD) in the latest Permian. The
presence of anomalous paleomagnetic directions in the late Permian sedimentary and volcanic sections
within Eurasia can be used as a powerful tool for local and regional magnetostratigraphic correlations,
and also suggests the Upper Permian age of the Nedubrovo sediments.
This work was funded by the grants #15-05-06843, 18-05-00593, 17-05-01121 (RFBR), #14.Z50.31.0017
(The Russian Government), MD1116.2018.5.
64
RATE AND FREQUENCY OF EXTREME GEOMAGNETIC FIELD
INTENSITY VARIATIONS
Yves Gallet1, Stanislava Yutsis-Akimova
1,2, Alexandre Fournier
1, Agnès Genevey
3,
Marie Troyano1, Phil Livermore
4, Maxime Le Goff
1, Michel Fortin
5, Shahrmardan
Amirov6
1 Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154
CNRS, F-75005 Paris, France
2 Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
3 Sorbonne Universités, UPMC Univ. Paris 6, CNRS, UMR 8220, Laboratoire d’archéologie
moléculaire et structurale (LAMS), Paris, France
4 School of Earth & Environment, University of Leeds, Leeds, UK
5 Faculté des lettres et des sciences humaines, Département des sciences historiques, Université
Laval, Québec, Canada
6 Archeological Institute, Russian Academy of Sciences, Moscow, Russia
Rapid or extreme intensity variations in geomagnetic field are being attracted much interest within the
archeomagnetism and geomagnetism communities. They are the subject of numerous archeomagnetic
studies accompanied by the construction of archeo/geomagnetic field models. These studies follow the
suggestion of geomagnetic "spikes" at the beginning of the first millennium BC proposed from
archeointensity results obtained in the Near East. These events would be characterized by geomagnetic
field intensity peaks over durations of only a few decades. They would imply variation rates of several μT
per year, i.e. more than ten times the maximum rate of intensity variations known for the recent
geomagnetic field. Such rates cannot be explained in the context of our current understanding of core
dynamics, and their reliability is therefore a crucial issue for the geomagnetists. It seems likely that other
episodes marked by strong intensity variation rates have occurred over the past millennia. With the aim to
provide new constraints on both the amplitude and frequency of extreme geomagnetic variations, we
recently carried out several studies dealing with the field intensity variations in the Middle East during the
6th and 3rd millennium BC. Our results show that these two periods were characterized by several short-
lasting intensity peaks, but the associated variation rates (a few tenths of μT/year at most) remain much
smaller than the values proposed for geomagnetic spikes. Our studies therefore do not allow one to
confirm the reality of geomagnetic spikes. However, they highlight the fact that geomagnetic intensity
peaks occurring on a time scale of the order of a century, associated with intensity variation rates of
between ~ 0.05 μT/year and ~ 0.25 μT/an, constitute an essential element of the geomagnetic field secular
variation.
65
THE UPPER CRETACEOUS PALEOMAGNETIC INVESTIGATION OF
NORTHEAST OF WESTERN SIBERIA
Gnibidenko Z.N.1, Levicheva A.V.
1, Semakov N.N.
1, Marinov V.A.
2
1 - Trofimuk Institute of Petroleum Geology and Geophysics, Novosibirsk,
2 - OOO “Tyumen Oil Scientific Centre”, Tyumen
Results of paleomagnetic investigations of the Upper Cretaceous sediments penetrated by three boreholes
– Harampurskaya 106P, Novochaselka 5P and West-Chaselka 1P, stripped in the territory of the Ust’-
Eniseisk region (the northeast of Krasnoyarsk Krai, West Siberia) are presented for the first time. The
studied sediments are presented by Pokur, Kuznetsovo, Lowerchaselka, Upperchaselka and Tanama
formations. All listed formations have the paleontological characteristic (foraminifera, molluscs) and its
formed in the Cenomanian to Maastrichtian time interval. In total, 698 oriented cubic specimens for 230
stratigraphic levels were selected from the studied sediments. The component analysis of NRM has
allowed to allocate characteristic remanent magnetization (ChRM). The studied sediments are
characterized by normal and reverse polarity. For each borehole magnetostratigraphic sections have been
constructed. Based on comparison and coordination of magnetostratigraphic sections of boreholes with
each other the summary magnetostratigraphic section of the Upper Cretaceous of the Ust’-Eniseisk region
covering stratigraphic units from the Cenomanian to Maastrichtian. This magnetostratigraphic section is
compared with the world magnetochronological scale of Ogg [Ogg et al., 2016]. In Upperchaselka
formation two magnetozones of the reversal polarity RK2m1 и RK2сp2 with one horizon of normal
magnetization in the magnetozone RK2сp2 are allocated. These magnetozones are correlated with Chrons
C31r and C32n.1r of this scale. Lowerchaselka, Kuznetsovo and Pokur formations have found normal
polarity and make one long magnetozone of normal polarity NK2t-st2 compared with Chron C34 of
normal polarity [Ogg et al., 2016].
PALEOMAGNETISM OF PALEOZOIC ROCKS OF THE EASTERN SLOPE
OF THE SOUTH URALS
Golovanova I.V., Danukalov K.N., Kosarev A.M., Sal’manova R.Yu.
Institute of Geology - Subdivision of the Ufa Federal Research Centre of the Russian Academy of
Sciences
Paleomagnetic studies in the Devonian and Carboniferous rocks of the South Urals can serve as an
independent test of ideas about the collision of the Magnitogorsk island arc and the passive margin of the
continent of Lavrussia. Here we present new paleomagnetic data on rocks of Devonian and Lower
Carboniferous age of the western and central parts of the Magnitogorsk zone. These data allow us to
compare coeval paleolatitudes of the Magnitogorsk island arc and the eastern edge of the East European
continent and determine the mutual movement of two tectonic elements. The sections of Devonian and
Lower Carboniferous volcanic and volcanic-sedimentary rocks in the Magnitogorsk zone of the South
Urals were studied. Altogether more than 1500 oriented samples were tested and their stepwise thermal
demagnetization was carried out. Interpretable results obtained for 15 Lower and Middle Devonian and 8
Lower Carboniferous sections. The high-temperature component of the magnetization, sometimes bipolar,
is isolated in the samples of the basic effusives of most of the sections studied and in the jasper. This
66
remanence resides in magnetite and hematite and is likely primary as indicated by the fold test and
reversal test both for the Devonian and the Lower Carboniferous samples.
The results of paleomagnetic studies allow us to draw the following conclusions. The passive margin of
the continent of Lavrusia and the nearby Magnitogorsk arc had a near-equatorial location. The position of
the edge of the continent and the island arc was close to sublatitudinal.
The calculated paleomagnetic pole for the Lower - Middle Devonian is quite close to the coeval pole of
the paleocontinent Baltica (Laurussia), which indicates the probable position of the Magnitogorsk island
arc the fairly close to the continent, but not in touch with it. Paleomagnetic data on rocks of the Lower
Carboniferous age may indicate that in the Early Carboniferous the Magnitogorsk island arc experienced
a turn, collided with the continent and formed a single whole with it.
The research was performed under State Programme 0252-2017-0013.
PALEOMAGNETISM OF ORDOVICIAN-SILURIAN VOLCANIC ROCKS ON
THE WESTERN SLOPE OF THE SOUTH URALS
Golovanova I.V., Danukalov K.N., Sergeeva N.D., Sal’manova R.Yu., Khatapov S.S.
Institute of Geology - Subdivision of the Ufa Federal Research Centre of the Russian Academy of
Sciences
There are very few paleomagnetic data on the Ordovician and Silurian Periods both for the western slope
of the Urals that is the deformed eastern margin of Baltica and the East European Platform as a whole.
Reliable actual paleomagnetic data for the East European platform for the interval 458-432 Ma ago are
absent. Meanwhile, the magnetic pole wanders considerably during this time.
In recent years, U/Pb zircon dating of Paleozoic rocks has been obtained by studying the age of
magmatites in the Bashkir Meganticlinorium previously assigned to the Precambrian. As a result, a Late
Ordovician-Silurian magmatic complex has been established, all dating for which fit within a narrow
interval of 435-455 Ma. The first results of the paleomagnetic study of one of the dated objects on the
Ushat River showed good agreement with the calculated Baltica’s Apparent Polar Wander Paths (APWP)
in the interval 437-442 Ma.
Here we present new data on the study of Ordovician-Silurian volcanic rocks from four dated sections in
the frame of the Taratash massif (a total of 16 flows). All these rocks are characterized by a strong
magnetic signal. Permian remagnetization is almost absent in the samples under study.
With the aid of stepwise thermal demagnetization, a high-temperature remanence was successfully
isolated. This remanence resides in magnetite and hematite and is likely primary as indicated by the fold
test. According to our calculations, the paleomagnetic pole has the coordinates 25.4° N and 199.7° E
(25.4° S, 19.7° E), A95=6,1° showing a good agreement with calculated data on Baltica for 440 Ma.
It was shown earlier that paleomagnetic results on Paleozoic rocks from the westernmost zones of the
Ural fold belt reveal not local and regional rotation with respect to Baltica; hence the obtained result may
be valid for the paleocontinent Baltica as a whole for time 437-442 Ma.
We think that new data give a new Ordovician-Early Silurian paleomagnetic determination that can be
used to refine the Early Paleozoic part of the Baltica’s APWP and for paleoreconstructions.
This study was funded by grant 18-05-00631 from the Russian Foundation of Basic Research.
67
LABORATORY MODELING OF THELLIER-COE PALEOINTENSITY
DETERMINATIONS ON ROCKS BEARING TCRM
Gribov S.K.1, Shcherbakov V.P.
1,2,3, Aphinogenova N.A.
1, Smirnov M.A.
1
1 - Geophysical Observatory “Borok” IPE RAS, Borok, Russia
2 - Kazan Federal University, Kazan, Russia
3 - IPE RAS, Moscow, Russia
One of the threats to obtain incorrect paleointensity (PI) data is the risk to misidentify NRM as TRM
while in reality the studied rock carries CRM or TCRM. The danger is aggravating by the inability to
distinguish CRM (TCRM) from TRM by any known means including the Thellier procedure. It was
shown experimentally (Draeger et al., 2006; Gribov et al., 2017) that PI values determined from samples
carrying laboratory induced CRM underestimate PI about 2 times. But equally important kind of chemical
remanence, TCRM, created during slow cooling of igneous rocks due to oxidation of titanomagnetites
was not investigate. Here we report results of such studies performed on laboratory. TCRM was created
in a thermomagnetometer first by quick heating to 570 C following by slow cooling in air at rate of 1
C/hour in the presence of an external field of B = 50 μT. A complex magneto-mineralogical studies,
comprising electron microscopy and X-ray diffractometry, have shown that creation of TCRM is
associated with the formation of highly oxidized titanomaghemites and the magnetite due to their
exsolution. Simulation of the Thellier method on these samples revealed that the application of this
technique to samples carrying TCRM yields a magnetic field very closed to the true one giving the error
of determination not more than 6 %. This result radically differs on that of obtained for the CRM and
provides a good hope that contrary to the common fears, TCRM and TRM may be equivalent sources for
true paleomagnetic information.
The work was supported by the state assignment 0144-2014-00117 and the RFBR grant 17-05-00259.
PRELIMINARY COMPOSITE MAGNETOSTRATIGRAPHIC SECTION OF
THE VALANZHINIAN OF THE CRIMEAN MOUNTAINS
Grishchenko V.A., Guzhikov A.Yu., Manikin A.G.
Saratov State University, Saratov
Within the works on the construction of the magnetostratigraphic scheme of the Valanginian in Mountain
Crimea, there were analyzed the paleomagnetic and petromagnetic data on the oriented samples, taken
from 363 stratigraphic levels of 10 sections in SW Crimea. The studied sediments of Valanginian
constitute an unfavourable objects in paleomagnetic terms in view of several factors (landslide
deformations, hypergene changes, presence of condensed slice and other factors). Anyway, the analysis
and generalization of obtained materials let us conduct their magnetic-polar interpretation and propose the
first layout of free magnetostratigraphic section of Valanginian in Mountain Crimea.
The border interval of Berriasian-Valanginian is represented in the mountain Crimea by deep water clay
facies. Unfortunately it is hardly deformed by landslides in the studied sections in the territory of
Feodosia region (Zavodskaya balka, Sultanovka and mtn. Koklyuk). Anyway, magnetostratigraphic
results are obtained, at least, in the Zavodskaya Balka section, where there were received the
68
paleomagnetic data on the underlying Berriasian sediments exposed by quarry. These materials are
reliable and satisfy most part of criteria, including standard field tests that are required for the quality of
similar data. By comparing the paleomagnetic column of Zavodskaya Balka section with Geologic Time
Scale (2016), for the first time in the Eastern Crimea, it became possible to justify the level of the lower
boundary of Valanginian in the area of reverse polarity magnetozone – analogue of M14r chron.
In SW Crimea there were studied the sections of Lower Valanginian, represented mostly by shoaly littoral
sandstones. Magnetostratigraphic data on the each of these sections individually may be reasonably
doubted due to the numerous anomalous paleomagnetic directions and abundance of sedimentation
breaks. However similar paleomagnetic structure is steady traced in 7 sections (mtn. Dlinnaya, mtn.
Sheludivaya, mtn. Patil, mtn. Bolshoy Kermen, mtn. Selbuhra, mtn. Rezannaya), that gives much more
trust to the received data. Magnetozones, established in the lower Valanginian of SW Crimea we
presumably identify as analogues of M15-M12 chrons.
Another key section of upper Valanginian is situated in SW Crimea near the mtn. Rezanaya (v.
Verhorechye) that was earlier studied by O. Yampolskaya (2006). We’ve conducted the more detail
sampling of this section and measured the samples using the cryogenic magnetometer 2G-Enterprices
(IPE RAS, Moscow). New paleomagnetic data specify available definitions and raise their authenticity. In
the paleomagnetic column as a result of complex analysis of bio-, magnetostratigraphic and isotope data
we’ve established the analogues of chrons M12, M11A, M11, M10N.
The research was financially supported by the RFBR (project 18-35-00134 mol_a).
UPPER CRETACEOUS MAGNETOSTRATIGRAPHY OF LOWER VOLGA
REGION
Guzhikova A.A., Guzhikov A.Yu., Manikin A.G., Grishchenko V.A.
Saratov State University, Saratov
In the Lower and Middle Volga region there are situated the key sections of Upper Cretaceous, which
could decide many actual problems of stratigraphy if their paleomagnetic study would have been done.
However, paleomagnetic properties of Upper Cretaceous sediments as in Volga region as on a whole
Russian Plate were completely unstudied. One of the main causes of current situation is extremely low
value of natural remanent magnetization of the carbonate rocks of Upper Cretaceous that is often lower
than limit sensibility of measuring equipment.
New high susceptible equipment including cryogenic magnetometers (SQUID) that became available at
the present time made possible the appearance of new paleomagnetic data on Turonian-Maastrichtian of
Saratov and Volgograd right bank of Volga, that satisfy most part of criteria, required for the quality of
paleomagnetic materials. For example, according to the evaluation system, proposed by A.N. Khramov in
the Supplements to the stratigraphic code of Russia (2000), their authenticity index is 7 (of possible 8).
This estimation was given by such features like tying layer by layer of the samples to the sections,
conducting magneto-mineralogical and component analysis, positive result of inversion test, forming
composite paleomagnetic column on several overlapping sections and more.
To date we have magnetostratigraphic data on the samples more than 500 different levels from 12 key
sections of Turonian - Maastrichtian of Saratov and Volgograd right bank of Volga.
The data on Campanian-Maastrihtian have a good agreement with traditional veiws about paleomagnetic
structure of this stratigraphic interval in Geomagnetic Polarity Time Scale (GPTS). In the paleomagnetic
zonality of Volga region sections there are identified the analogues of all the magnetic chrons, covering
the interval of Campanian-Maastrichtian, except for late Maastrihtian short C30r and C29r, corresponding
to the border interval of Cretaceous-Paleogene. On the results of integrated (bio-, magnetostratigraphic
69
and isotope) studies we managed to trace the lower border of Maastrichtian from GSSP, situated in SE of
France, to the Russian Plate, specify the age of Campanian-Maastrichtian local stratigraphic units
(formations) and show the diachroneity of their borders.
In several sections of Turonian-Santonian of Volga region there was established a large reversal polarity
magnetozone that contradicts with the data of GPTS. At the present time we could not find the convincing
arguments in favor of remagnetization of rocks by aftersantonian geomagnetic field and, so, the
hypothesis of the presence of longstanding epoch (epochs) of reversal polarity in Turonian-Santonian has
the priority to existence.
ESTIMATION OF THE POSITION OF ARCH. NOVAYA ZEMLYA AT THE
PERMIAN TIME ACCORDING TO PALEOMAGNETIC DATA
Iosifidi A. G.1,2
1- All-Russia Petroleum Research Exploration Institute (VNIGRI), St. Petersburg, 191014 Russia
2- Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, St. Petersburg
Branch, St. Petersburg, 191023 Russia
Reconstruction of ancient sedimentation basins by the paleomagnetic method is important, both for
deciphering the history of their formation, and for the practice of prospecting for minerals. One of the
promising areas for the search for minerals is the Barents-Kara region. From the north it is bounded by
the Spitsbergen archipelago, the Franz Josef Land, the Severnay Zemya, and from the south by the
Eastern European platform with the Pechora plate included in it and the Siberian plate. In the center of the
region is the archipelago Novaya Zemlya. The existing paleomagnetic data for Paleozoic and Mesozoic
deposits of the Novaya Zemlya archipelago are few and do not always meet modern reliability
requirements. Nevertheless, according to the results of the first studies [Gurevich, Slautzitis, 1988], it was
concluded that in the early Triassic the lithosphere block, which includes Novaya Zemlya and Franz Josef
Land, located west of its present position with respect to the Russian platform and was rotate
approximately 20 degrees counter-clockwise. In our work, we present new data on the Permian sediments
of the southern island of the Novaya Zemlya archipelago from three sections (the Gusinaya Zemlya
Peninsula and in the Rogachev-Taininsky District: the Severo Taynay River and the Margantsevyi
Creek). The analysis of the data from the works [Gurevich, Slautzithis, 1984], [Abashev et al., 2017] and
the new paleomagnetic determinations obtained is carried out. The Permian structures of the southern
island of the Novaya Zemlya archipelago were laterally rotated clockwise by 28-34 degrees with respect
to the Russian Platform.
70
PALEOMAGNETIC STUDIES OF CARBONIFEROUS DEPOSITS OF THE
RUSSIAN PLATFORM
Iosifidi A. G.1,2
, Sergienko E. S.3, Salnaia N. V.
4, Otmas N. M.
1, Zuravlev A. V.
5,
Mikhailova V. A.1, Popov V. V.
1,3, Danilova A. V.
1
1- All-Russia Petroleum Research Exploration Institute (VNIGRI), St. Petersburg, 191014 Russia
2- Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, St. Petersburg
Branch, St. Petersburg, 191023 Russia
3- St. Petersburg State University, St. Petersburg, 199034 Russia
4- Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
5- Institute of Geology, Komi Science Center, Ural Branch of the Russian Academy of Sciences,
Syktyvkar, Russia
Paleomagnetic studies of the Carboniferous deposits of the Russian Platform were started since the fifties
of the last century. The quality of the available data does not always meet modern reliability criteria. In
this paper, we present the results of paleomagnetic studies of the Carboniferous deposits of the Russian
Platform, conducted in 2016-2018, which covers a time interval of 340 to 300 million years. During the
stepwise thermal demagnetization four NRM components are isolated: component A (a present viscous
component); the characteristic component C1 corresponding to the Carboniferous time, which in some
cases correlates with the data of other researchers (a positive agreement test, class B); characteristic
component P reflecting the Late Paleozoic remagnetization (mean Permian) and component C0, which
indicates the presence of large particles or their aggregates in red clay. The main feature of the obtained
data is the predominance of components of the natural remanent magnetization of the reverse polarity.
Only in one section (Lyubytinsky district, Novgorod region) the bipolar component C1 is distinguished
along the deposits of the Aleksin horizon of the Visean stage. The positions of the obtained
paleomagnetic poles (component C1) show the movement of the Russian platform to the north with a
clockwise rotation of 35 degrees and with a latitude offset of about 14 degrees. Comparison of the
average paleomagnetic pole of the component P (N = 7, Lat = 48o, Long = 156
o, A95 = 3
o) with the one-
age component P2 (N / n = 28/51, Lat = 47o, Long = 168
o, A95 = 4
o) on red clay from outcrops along the
river Kamа allows estimating the possible shallow of the inclination of 6 degrees.
The work was supported by the Russian Foundation for Basic Research under the project no. 16-05-
00603a.
71
EXPLORING THE INFLUENCE OF THE GEOMAGNETIC POLARITY TIME
SCALE ON RESULTS OF THE GEOCHRONOLOGICAL AND
GEOHISTORICAL ANALYSIS OF THE MARINE MAGNETIC ANOMALIES
S. A. Ivanov1 and S. A. Merkuryev
1,2
1 - Pushkov Institute of Terrestrial Magnetism of the Russian Academy of Sciences, St Petersburg
Filial. 1 Mendeleevskaya Liniya, St Petersburg 199034, Russia
2 - Saint Petersburg State University, Institute of Earth Sciences, Universitetskaya nab.,7-9, St.
Petersburg 199034, Russia
Since Vine and Matthews’ hypothesis, several tens of magnetic polarity time scales were constructed,
according to the studies of marine magnetic anomalies (MMA). The appearance of new scales is usually
associated with both the refinement of the scale structure and the use the methods of time scale
calibration.
On the basis of these scales, MMA have been identified in all the world's oceans, a digital age grid of the
ocean floor was created [Muller et all, 2008], and the global digital MMA identification data set was
incorporated into online downloadable repository [M. Seton et all, 2014]. From these MMA
identifications the spreading regime of the ocean floor can be ascertained and a plate kinematic model
calculated. Thus, for geochronological and kinematic interpretation of MMA the calculations use data of
the geomagnetic field inversions, and therefore the results of these calculations depend on the used scales.
We have conducted a study of how the choice of the scale affects the results of the geochronological and
geohistorical interpretation of MMA in the northwestern part of the Indian Ocean. For the analysis, 15
most well-known Cenozoic scales were selected, starting with the time scale of Heitzler et al. (1968) and
ending with the latest published scale of Gradstein et al. (2012). The study of the two periods of the scales
was conducted for times of C1-C5 and C23-C26 chronos because they correspond to steady-state regime
and the spreading rate was substantially did not change [Merkouriev, S., C. DeMets, 2006].
First, the identification of parts of the profile and segments of the given scale was carried out. For the
given spreading rate, a model field was calculated and the correlation coefficient of the section of the
observed profile and of various sections of the model profile was considered. Then this procedure was
repeated for a model profile constructed with a different spreading rates. The correspondence between the
section of the profile and the section of the scale was determined by the maximizations of the correlation
coefficient both by the position of the section of the scale and by the spreading rate.
The study revealed the following effects:
1. The age of identified anomalies, depending on the choice of scale, may differ by 10%, and for
younger anomalies (chrones C1-C5), more modern scales give a more ancient age, and for older
anomalies give a younger age what leads to the corresponding variations of the spreading rates.
The spread of ages for ancient anomalies is greater than for the young ones.
2. It is shown that at the stage of identification of anomalies, the magnitude of the correlation
coefficients depends on which scale was used in the simulation. In general, the use of more
modern scales provides a higher correlation coefficient between observed and model profiles.
However, the maximum correlation coefficients for ancient and young anomalies are not always
achieved for the same scale.
3. The scatter of differential linear spreading rates over the last 10 million years, calculated on the
basis of the kinematic rotation model of the Indian and Somali plates [Merkouriev, S., C.
DeMets, 2006], is smaller when using scales with astronomical age calibration.
72
THE AGGREGATION OF SUPERPARAMAGNETIC PARTICLES UNDER IN-
PHASE AND ANTIPHASE OSCILLATIONS OF THEIR MAGNETIC
MOMENTS
Karimov F.H.
Institute of earthquake engineering and seismology of the Academy of sciences of the Republic of
Tajikistan
Two superparamagnetic particles interacting under in-phase and antiphase thermoactivated total magnetic
moments oscillations are considered. In case of in-phase oscillations, both particles’ magnetic moments
rotate in the same directions, while under antiphase oscillations in the opposite ones including in-plane
and perpendicular plane of its polarizations. For simplicity, the particles are assumed to be spherical. The
dipolar interaction energy is about equal to the magnetocrystalline anisotropy one for the magnetite
particles at the normal physical conditions and so they both create principal energy barriers for the
magnetic moments. At this ideal respect the shape and surface anisotropies don’t play a role in the
aggregation. With antiphase oscillations of magnetic moments there is a permanent attraction between
particles. With in-phase vibrations the repulsive forces turn up doing the particles move away from each
other, when deflection angle of the magnetic moments of line, connecting the particles’ centers, ranges
within the interval from arccos √33
⁄ up tо 𝜋 − arccos √33
⁄ . Analysis of the standard equation for the
movement of a particle under the dipole magnetic forces leads to the following conclusions:
With in-phase oscillations of the magnetic moments of superparamagnetic particles the aggregation
permanently breaks and restores along with time. The degree of aggregation is determining by means of
nondimensional parameter 𝐶 = 𝐽2
𝜌𝜔2𝑟2⁄ , where 𝑟 is a particle’s radius, 𝐽 is particles’ magnetization, 𝜌
is their substance density, 𝜔 is the circular frequency of magnetic moments’ oscillations. 𝐶 is equal to 10
by the order of magnitude for the magnetite particles at 𝜔 = 109 Hz and 𝑟 = 10 nm. The run-away distance
between disaggregated 10 nm particles doesn’t exceed about 0.05 𝑟 and is of the same order of magnitude
for the 1 nm ones. For the frequency 108 Hz the tear off distance is longer. Tiny and light enough particles
with weak enough magnetization aggregate and disaggregate almost strictly following the dipolar
oscillations, but some heavy ones, due to the inertia, aggregate later. But in both cases the particles get
aggregation state by the beginning of the next oscillation cycle;
The probability for the realization of aggregated state with antiphase oscillations in
superparamagnetic particles is higher than for in-phase one, because of higher dipolar magnetic
interaction energy barrier in the last case;
Due to the energy barrier rise caused by dipolar magnetic attraction the relevant
superparamagnetic particles transform to stable quasi single domain ones and the probability for
realization of aggregated state also became higher than for disaggregated one;
At elevated temperatures, but below the Curie temperature, the oscillation frequency raises and
according to the parameter 𝐶 the aggregation probability falls down.
73
ROCK-MAGNETIC AND GRAIN SIZE DATA ON THE QUATERNARY
MULTI-LAYERED KEY SECTION TOLOGOY (BURYATIA, RUSSIA)
Kazansky A.Yu.1,2
, Matasova G.G.3, Shchetnikov A. A.
4, 5, 6, Filinov I. A.
4,5,6
1- Geological Department of Lomonosov Moscow State University, Moscow, Russia
2- Geological Institute of Russian Academy of Sciences, Moscow, Russia
3- Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of
Sciences, Novosibirsk, Russia
4- Irkutsk State University, Irkutsk, Russia
5- Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences, Russia
6- Irkutsk Scientific Centre, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
The multi-layered key section Tologoy is located on the Selenga River left bank, 15 km southwest of
Ulan-Ude city (51º45’ N, 107º29’ E), in the Western Trans-Baikal region. It holds a long record of
Quaternary sedimentation since Early Pleistocene through Holocene. The section is composed of 20 m
thick succession of silt, sandy silt and sand with fossil soil horizons. 200 samples for rock-magnetic and
grain size analysis were taken each 10 cm over the section.
Grain size results allowed to improve the field description of the section and to give its more detailed
subdivision, particularly two additional fossil soils were recognized in the upper and lower parts of the
section.
Magnetic fraction of the sediments is closely connected with silt granulometric fraction. Correlation
coefficients between silt fraction and concentration-sensitive rock-magnetic parameters exceed 0.55 in the
upper part of the section and 0.7 in its lower part. It means that magnetic grains are mostly of terrigenous
origin.
Variations of rock-magnetic parameters over the section clearly reflect its structure in accordance with so
called “Siberian mechanism”. Concentration-sensitive parameters (magnetic susceptibility, different types
of magnetization) have low values in fossil soils and enhanced values in surrounding silt and sand. The
fossil soils also contain more high coercivity minerals and superparamagnetic grains as well as
paramagnetic material. Magnetic grain size in fossil soils is smaller, however in the fossil soils from the
lower part of the section and proportion of SD grains in their assemblages is slightly higher than in the
upper part, thus indicating more warm and humid climatic conditions.
Anisotropy of magnetic susceptibility of the strata demonstrates a typical sedimentary texture; however,
sedimentation here occurred on the slope inclined to the west. The main direction of paleotransport of
sedimentary material was changing gradually in time from N-S to NE-SW.
This work was supported by the Russian Foundation for Basic Research (project no. 18-05-00215, 16-05-
00586) and Ministry of education and science of the Russian Federation (project no. 2017-220-06-1656).
74
MAGNETIC PROPERTIES OF BRICKS: SUPERPARAMAGNETISM AND
PRESENCE OF HIGH-COERCIVITY-LOW-UNBLOCKING-TEMPERATURE
MAGNETIC PHASE
P.V. Kharitonskii1, A. Kosterov
2, I.M. Berestnev
2, E.S. Sergienko
2
1 Saint-Petersburg State Electrotechnical University “LETI”
2 Saint-Petersburg State University
Archaeological ceramics is the most important material from which the information on the geomagnetic
field behavior during the last several millennia can be extracted. The magnetic mineralogy of bricks and
ceramics in general is commonly considered as quite simple and straightforward, main magnetic phases
being hematite and magnetite/maghemite. However, recently it was recognized [McIntosh et al., 2007,
2011] that a high-coercivity-low-unblocking-temperature (HCLT) magnetic phase is also present in many
ceramic samples, identified tentatively as ε-Fe2O3 [López-Sanchez et al., 2017].
Towards this end, we investigated a small collection of bricks from different regions of European Russia,
having ages from recent to mid-18th century. Magnetic measurements included room-temperature
hysteresis loops and backfield curves, and thermomagnetic analysis at high and low temperatures. To
specifically address the presence of ultrafine superparamagnetic particles, we measured the frequency-
dependent initial magnetic susceptibility at room temperature, and, for selected samples, also as a
function of temperature between 2 K and 300 K. Additionally, samples were analyzed using scanning
electron microscopy and X-ray diffraction.
According to the magnetic measurements, none of our samples contain stoichiometric magnetite though a
phase with Curie temperatures in the 500-600°C is omnipresent. We infer it to be an oxidized
magnetite/maghemite, possibly also cation-substituted. Curie temperatures which would correspond to
hematite were not detected. At the same time, inflection points around 200°C characteristic of a HCLT
phase [McIntosh et al., 2007, 2011] were observed in most samples. The presence of this phase is further
supported by room-temperature hysteresis loops which (i) do not saturate in the highest available field (2
T) and (ii) yield rather strong high-field magnetization which would require an unfeasibly large amount of
a hematite-like phase to explain it. Finally, in most samples we observe a strong frequency dependence of
susceptibility extending from ~ 20 K to room temperature and possibly above.
This study was partially supported by the RFBR grant No. 18-05-00626 and used the equipment of the
resource centers of the Science Park of St. Petersburg State University: Geomodel, Centre for Diagnostics
of Functional Materials for Medicine, Pharmacology and Nanoelectronics, and Centre for X-ray
Diffraction Studies.
75
PETROMAGNETIC LEGEND OF THE BASIS OF THE EASTERN BOARD OF
THE TUNGUS SYNECLISE (WORKING OPTION)
Alexander A. Kirguev1, Konstantin M. Konstantinov
1,2, Alexanderа E. Vasilyeva
3
1Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia,
Sakha Republic, Mirny, Chernychevskoe St., 16, Russia
2Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
3Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980,
Yakutsk, Lenin St., 39, Russia
In the process of its formation, the basites of the Tungus syneclise, due to the physico-geological laws of
formation, formed inside the bodies (sills, dikes, etc.) petromagnetic taxons (PMT), which are
characterized by certain statistical values of density and magnetic parameters. According to the nature of
their distribution, PMT are subdivided into petromagnetic groups (PMG) and petromagnetic
heterogenetics (PMHs). In its turn, PMT is composed of petromagnetic complexes (PMC), corresponding
to the magmatic phases of the introduction of basites. Three phases were distinguished in the scheme of
development of trap magmatism of the eastern side of the Tunguska syneclise: 1 - intrusive γβP2, 2 -
volcano-subvolcanic β0-γβP2-T1 and 3 - intrusive γβT1. PMT allow more securely zoning of the Yakut
diamondiferous province closed by the trap areas in order to develop a methodology for prospecting for
indigenous diamond deposits, as well as isolating structural and tubular types of anomalies over
kimberlite pipes based on gravimagnetic exploration materials.
On the basis of the geological legend, a petromagnetic legend was developed that makes it possible to
classify the basalts of the eastern side of the Tunguska syneclise along the introduction phases with a high
degree of probability. It is known that at the time of its formation, the traps of the first and second
introduction phases were magnetized positively (sub-consistent with the current field), and the third
phase-negatively.
The most informative magnetic parameters that reflect changes in the conditions of crystallization of
basites are magnetic susceptibility (æ), natural remanent magnetization (NRM) and Koenigsberger
coefficient (factor Q). On their basis, PMG are well distinguished as the taxa of traps, the magnetic
characteristics of which vary in space (differentiation, contamination, etc.) for homogeneous chemical,
petrographic, etc. parameters. Depending on this, the amount of PMG can be infinite. PMHs is a PMT of
traps, which magnetic characteristics vary in time. Nowadays, in Permo-Triassic basites are established
four genetic types of PMHs: the first type was formed due to magnetization by the reversal geomagnetic
field; The 2-nd type is due to the roasting of basites of early phase by introduction of a late Intrusive
phase; the 3-rd type - as a result of the effect of self-reversal of titanomagnetites; 4th type - due to
lightning strikes
PMHs completely and easier explain the presence in the one or another phase of the basilitic magmatism
of the eastern side of the Tunguska syneclise of vectors of the EOH opposite sign, than the previously
advanced petromagnetic legends. The distribution of the current magnetization vectors of Permotrias traps
of the eastern side of the Tunguska syneclise is subject to strict statistical regularities, by means of which
their components (intensity and direction) can be calculated. The established regularities will allow to
significantly improve the quality of physical and geological modeling of magnetic fields in the territories
of IV and V geotypes.
76
PETRO- AND PALEOMAGNETIC CHARACTERISTICS OF KIMBERLITES
AND BASITES IN THE KYUTINGDE GRABEN (NORTHEASTERN
SIBERIAN PLATFORM)
Innokentiy K. Konstantinov1, Konstantin M. Konstantinov
1,2, Mikhail D. Tomshin
3,
Dimitri P. Gladkochub1, Andrey A. Jakovlev
2, Alexandra E. Vasil’eva
3
1Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
2Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia,
Sakha Republic, Mirny, Chernychevskoe St., 16, Russia
3Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980,
Yakutsk, Lenin St., 39, Russia
The present study of the Kyutingde graben rocks is a logical continuation of investigations of the
geological structure and the development history of the northeastern Siberian platform (Gladkochub et al.,
2009; Wingate et al., 2009; Konstantinov et al., 2012). Magmatic activity in the area was controlled by
the NW-striking Molodo-Popigay fault zone, and had a repeated character. We have studied dolerite dikes
and sills of the Molodo-Udzha (PZ2mu) and Molodo (P2-T1ml) intrusive complexes as well as Middle
Mesozoic kimberlites of the Kuoika field (Velikan dike, Obnazhyonnaya and Ruslovaya pipes).
The study revealed significant differences in petrophysical parameters of the basites of the Molodo-Udzha
and Molodo intrusive complexes, kimberlites, and their host rocks. On the background of the host rocks,
all these magmatites are manifested by positive magnetic anomalies of different amplitude and form.
Paleomagnetic directions for the Devonian basites are divided into two clusters. One of them correlates
well with the data obtained for the Appaya Formation (Frasnian, 385-375 Ma) while the other is
characteristic of older times (470-460 Ma) and cannot be adequately explained in the context of epochs of
tectonomagmatic activation. Vectors of the characteristic natural remanent magnetization (NRM) for the
Permo-Triassic basites have positive polarity (N), those for the Obnazhyonnaya and Ruslovaya kimberlite
pipes have negative polarity (R), and for the Velikan dike variable polarity (NR). It is obvious that
formation of the studied kimberlites followed the emplacement of the Permo-Triassic basites, most likely
in Late Triassic-Middle Jurassic times (250-160 Ma).
References
Gladkochub, D.P., Stanevich, A.M. et al., 2009. The Mesoproterozoic Udzha Paleorift (Northern Siberian
Craton): New Data on Age of basites, Stratigraphy, and Microphytology. Doklady Earth Sciences, Vol.
425A, No.3, pp.371-377.
Konstantinov, K.M., Tomshin, M.D. et al., 2012. Paleomagnetic and petrogeochemical characteristics of
Early Mesozoic basites in the Udzha River basin (northeastern Siberian Platform). Lithosphere, No. 3, pp.
80-98 (in Russian).
Wingate, M. N.D., Pisarevsky, S.A. et al., 2009. Geochronology and paleomagnetism of mafic igneous
rocks in the Olenek Uplift, northern Siberia: Implications for Mesoproterozoic supercontinents and
paleogeography. Precambrian Research 170, pp. 256-266.
77
PALEOMAGNETIC CHARACTERISTICS OF DOLERITE DYKES OF THE
VILUY-MARKHA FAULT ZONE (YAKUT DIAMONDIFEROUS PROVINCE)
Konstantin M. Konstantinov1,2
, Shamil Z. Ibragimov3, Innokentiy K. Konstantinov
2,
Alexander A. Kirguev1, Mikhail D. Tomshin
4,
1Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia,
Sakha Republic, Mirny, Chernychevskoe St., 16, Russia
2Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
3Institute of Geology and Petroleum Technologies, Kazan (Volga Region) Federal University, Kazan,
420111, Kremlyovskaya St. 4/5, Russia
4Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980,
Yakutsk, Lenin St., 39, Russia
On the operating fields of «ALROSA» (PJSC) Mir and Nyurbinskaya of the Yakut Diamondiferous
Province (YDP) are carried out petro-and paleomagnetic studies of dolerites from the pre-kimberlite
dykes of a Viluy-Markha intrusive complex. Basic distinctions of dolerites of two fields are observed on
values of a magnetic susceptibility of æ, the natural remanent magnetization (NRM) and a factor of Q.
For dolerites of the pit Nyurbinsky factor Q=1.31 - is considerably higher in comparison with other mafic
intrusions of the middle Paleozoic Q<0.8 (Kravchinsky et al., 2002.). It can be considered as a
petromagnetic marker of mapping the pre-kimberlite dykes as a part of the Viluy-Markha fault zone.
Results of magnetic-mineralogical studies of dolerites demonstrate that their anisotropy of a magnetic
susceptibility corresponds to morphology of bodies - to «dykes» type, the main mineral which is
responsible for magnetization is titano-magnetite that is almost not oxidized (primary), and its domain
structure treats pseudo-one-domain area of ferromagnetic particles.
In the studied samples negative vectors of characteristic NRM which form two independent clusters in the
first quarter of the stereogram are established. On each of them the paleomagnetic pole which is
compared with the apparent polar wander path (APWP) of the Siberian platform is calculated.
Paleomagnetic data show that the emplacement of Mirniy and Nyurba dyke complexes happened at
different times: 380 Ma (late Devonian) and 420 Ma (late Silurian-early Devonian) consequently.
Perhaps, they belong to two different dyke swarms. The younger corresponds to eruption of Appaya suite
basalts (Frasnian, 375-385 million years) and well fit with an age of the kimberlites of Mir pipe which are
breaking through a dyke (Famennian, 360-375 million years). Paleomagnetic date of older dyke swarm
well coincides with poles the kimberlites of pipes Nyurbinskaya and Botuobinskaya that testifies to
insignificant time difference of their emplacement. The obtained data confirm existence in the YDP two
events of kimberlite eruption: late Silurian-early Devonian (S2-D1) and late Devonian-early Carboniferous
(D3-C1).
References
Kravchinsky V.A., Konstantinov K.M. et al., 2002. Paleomagnetism of East Siberian traps and
kimberlites: two new poles and paleogeographic reconstructions at about 360 and 250 Ma / Geophys. J.
Int. 48. pp. 1-33.
78
PALEOMAGNETISM OF DOLERITE DIKES OF THE CHARA-SINSK FAULT
ZONE (ALDAN BLOCK OF THE SIBERIAN PLATFORM)
Konstantin M. Konstantinov1,2
, Innokentiy K. Konstantinov2, Shamil Z. Ibragimov
3,
Mikhail D. Tomshin4, Andrey A. Jakovlev
1
1Geological Enterprise of Exploration, Public Joint Stock Company «ALROSA» 678174, Yakutia,
Sakha Republic, Mirny, Chernychevskoe St. 16, Russia
2Institute of the Earth’s Crust, Siberian Branch of RAS, 664033, Irkutsk, Lermontov St., 128, Russia
3Institute of Geology and Petroleum Technologies, Kazan (Volga Region) Federal University, Kazan,
420111, Kremlyovskaya St. 4/5, Russia
4Institute of the Diamond and Precious Metal Geology Institute, Siberian Branch of RAS, 677980,
Yakutsk, Lenin St., 39, Russia
Situated on the southern shoulder of the Vilyui paleorift system is an extensive dike belt controlled by the
Chara-Sinsk fault zone (CSFZ). The latter extends northeasterly for 750 km, ranging in width from 50 km
in the southwest to over 120 km in the northeast. Dike belts normally associate with the intrusive facies
basites manifested as dikes, sills and chonoliths intruding into Cambrian, Ordovician and, less frequently,
Silurian carbonate and argillo-carbonate deposits. The intrusions are characterized by weak intra-chamber
differentiation. A particular body normally contains one rock variety most often represented by prismatic
ophitic gabbro-dolerites.
The dolerite dikes were studied in the bank exposures of the Lena River and its tributaries (Chara,
Sinyaya, etc.). The age of the basites is estimated at 364-362 Ma. The dolerite and gabbro-dolerite
composition of the older dikes change into sub-alkaline quartz gabbro-dolerites, monzonite porphyries,
syenites, etc. in the younger dikes (Tomshin, 1990). Petromagnetic and magnetic-mineralogical data are
available for all of the studied dikes. Most suitable for paleomagnetic studies were dolerites from the
eastern side of the CSFZ.
The laboratory demagnetization experiments on dolerites made it possible to determine directions of
characteristic natural remanent magnetization (NRM) of which the nature can be interpreted as primary as
shown by burning and reversal tests. For the studied dikes (N=7), a preliminary paleomagnetic pole is
calculated, with the coordinates: latitude =15.6o, longitude =78.3
o, and confidence interval
dp/dm=9.1/13.2o. The pole is located to the west of the Middle Paleozoic poles, which supports the
hypothesis of the clockwise rotation of the Aldan block with respect to the Anabar-Angara one as a result
of opening of the Vilyui paleorift in the eastern Siberian platform (Pavlov et al., 2008; Tomshin,
Konstantinov, 2005).
References
Tomshin, M.D., Koroleva, O.V., 1990. Composite dykes of the Vilyisk paleorift system, Siberian
platform, Yakutia / Mafic dykes and emplacement mechanisms / Rotteerdam. Brockfield, pp. 535-540.
Tomshin, M.D., Konstantinov, K.M., 2005. Basic dike belts of the Vilyui paleorift (Siberian platform) /
Fifth International Dyke Conference IDC 5, Rovaniemi, Finland, p. 51.
Pavlov, V., Bachtadse V., and Mikhailov, V., 2008. New Middle Cambrian and Middle Ordovician
palaeomagnetic data from Siberia: Llandelian magnetostratigraphy and relative rotation between the
Aldan and Anabar-Angara blocks // Earth and Planetary Science Letters, V. 276 (3-4), p. 229-242.
79
THE MAGNETIC PROPERTIES OF LAKE TURGOYAK SEDIMENTS
(CHELYABINSK REGION, RUSSIA)
L. Kosareva 1, D. Nurgaliev
1, P. Krylov
1, D. Kuzina
1, V. Antonenko
1, A. Yusupova
1,
V. Vorob’ev 2, V. Evtygin
2
1 – Institute of Geology and Petroleum Technologies, Kazan Federal University, Russia
2 – Interdisciplinary center for analytical microscopy, Kazan Federal University, Russia
In this work we perform results of magneto-mineralogical investigations of Lake Turgoyak sediments
(Chelyabinsk Oblast, Russia (55°09′N, 60°04′E)). Before sampling on the lake were conducted
seismoacoustic investigations for studying the sediments stratification. Total 5 cores with the lenght
between 4 to 6 meters were obtained. The magnetic susceptibility, NRM, hysteresis parameters and
induced magnetization versus temperature, TEM and SEM microscopy were carried out to determine
samples magnetic mineralogy. C14 dating was made for 10 samples.
NRM values vary within 0.134 – 4.05·mA/m, magnetic susceptibility 0.35 – 18.3510-5
SI. According
thermomagnetic diagrams sediments can be devided into 4 groups by depth: 0 – 1,42 m, 1,44 – 2,80 m,
2,82 – 3,80 m, 3.82 – 5,40 m. The Day-Dunlop diagram obtained from hysteresis parameters allows one
to draw conclusions about the presence in the sediments of a mixture of MD, SD (probably of biogenic
origin), PSD and possibly very fine SP particles. On the basis of petromagnetic properties of sediments
made conclusions of different stages of sedimentation in lake and changes in paleoclimate of this region
during Holocene and Upper Pleistocene.
This work was funded by the subsidy 5.3174.2017/4.6 allocated to Kazan Federal University for the
state assignment in the sphere of scientific activities and RFBR according to the research project 17-
05-01246.
HIGH-FIELD HYSTERESIS AND LOW-TEMPERATURE MAGNETIC
PROPERTIES OF HEMATITE- AND GOETHITE-BEARING SEDIMENTS
A. Kosterov1, E. Sergienko
1, A. Iosifidi
2,3, S. Yanson
1
1Saint-Petersburg State University
2 All-Russia Petroleum Research Exploration Institute (VNIGRI)
3 Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, St. Petersburg Branch
Continental sedimentary rocks and particularly red beds often contain magnetically hard mineral phases
such as hematite and goethite. In this case, magnetic hysteresis loops measured in moderate (< 2 T) fields
can serve but a qualitative criterion for the presence of these minerals. We therefore measured room
temperature hysteresis loops in a 7 T field and DC backfield demagnetization curves in fields up to 3 T
using a MPMS 3 instrument. These were complemented by thermomagnetic analysis at low and high
temperatures, microscopic observations, and X-ray diffraction study. Sediments from different regions of
the East European platform, mostly of Carboniferous age were used for this study.
80
High-field magnetic hysteresis loops alone appear not sufficient to definitely discriminate goethite from
hematite, though there is, expectedly, a tendency that increasing goethite content leads to magnetic
hardening, sometimes to the extreme, coercive force reaching 1 T and coercivity of remanence 1.7 T. At
the same time, combining these with the low-temperature magnetic measurements provides a better
insight into the magnetic mineralogy of sediments. Still, acquiring the reference data on well
characterized goethite and hematite samples is highly desirable.
This research has been partly supported by RFBR, grant No. 16-05-00603.
PALEOMAGNETISM OF PHANEROZOIC GEOLOGICAL COMPLEXES OF
MONGOLIA AND TUVA
D.V. Kovalenko
Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS (IGEM RAS)
Analysis of the pre-folded close to the primary magnetization showed:
1. The Caledonian block moved independently of the Siberian craton from Ordovician to Devonian, and
was located to the North of the Siberian continent (Fig.1).
2. In Devon there was a tectonic combination of the Caledonian block and Siberia (Fig.1). This event was
associated deformation rocks, granitoid and mantle magmatism.
3. The Caledonian block's strata rotated in a horizontal plane relative to Siberia, possibly due to the
transpressive type of collision.
4. In the late Carboniferous-Permian paleolatitudes Caledonian block significantly different from the
Siberian paleolatitudes. Perhaps this difference is due to the formation of the Mongolian-Okhotsk ocean.
Analysis post-folded magnetization showed:
1. In early Phanerozoic rocks of Mongolia and Tuva are allocated to the secondary component of
magnetization of normal and reverse polarity.
2. Components of the magnetization of the normal polarity associated with the Mesozoic remagnetization.
Components of reverse polarity, apparently, was formed in late Carboniferous-Permian in the period
superchron reverse polarity.
3. The analysis of the distribution of the reverse polarity magnetization components in the Mongolian
structure allows for zoning. The regions of Mongolia with minor post-Permian deformations of the rocks,
with complex post-Permian deformations and large blocks rotated around the horizontal axis are
distinguished (Kovalenko, 2017).
References
Kovalenko D. V. Chernov, E. E. Paleomagnetism of the Carboniferous-Permian magmatic complexes of
the southern part of Mongolia. Physics of The Earth. 2008, No. 5, p. 81-96
Kovalenko D. V. Paleomagnetism of early Paleozoic geological complexes of Mongolia. Physics of the
Earth. 2017. No. 3. p. 88-106.
Pavlov, V. E., Paleomagnetism of the Siberian platform. Abstract on competition of a scientific degree
doctor of physics and mathematics sciences. Moscow. 2015.
Bachtadse V., Pavlov V.E., Kazansky A.Y. et al. Siluro-Devonian paleomagnetic results from the Tuva
Terrane (southern Siberia, Russia)' implications for the paleogeography of Siberia // J. Geophys. Res.
2000. 105 (B6). P. 13,509-13,518
81
Besse, J., Courtillot, V., 2002. Apparent and true polar wander and the geometry of the geomagnetic field
over the last 200 Myr. J. Geophys. Res. 107 (B11), 6–31.
Van Hinsbergen D., Straathof G.B., Kuiper K.F., Cunningham W.D., Wijbrans J. No vertical axis rotation
during neogen transpressional orogeny in the NE Goby Altai: coinciding Mongolian and Eurasian early
cretaceous apparent polar paths // Geophys. J. Int., 2008, N173, p.105-126.
Fig.1. Paleolatitudes calculated from the paleomagnetic poles of Siberia (1) (Pavlov, 2016; Besse and
Courtillot, 2003) and the Caledonian Central Asia block (2) (Kovalenko, 2017; Kovalenko, in print;
Bachtadse et al., 2000; Kovalenko, Chernov, 2008; Van Hinsbergen, 2008).
RHYTHMS OF THE PALEOINTENSITY CHANGES WITH
CHARACTERISTIC TIMES 5 AND 1 MA
A.Yu. Kurazhkovskii, N.A.Kurazhkovskaya, B.I.Klain
Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian
Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
[email protected]; [email protected]; [email protected]
Significant gaps in the information on variations in the geomagnetic field intensity exist. For example,
until recently there were no paleomagnetic data, which allowed us to study variations of the
paleointensity with characteristic times of 1‒10 million years. We have carried out a generalization of the
fragmentary data of the Jurassic - Paleogene paleointensity obtained by the sedimentary rocks of the
Russian plate and adjacent territories. As a result, curve of the behavior of the geomagnetic field intensity
at the Jurassic - Paleogene interval (167-20 Ma) was obtained. Spectral analysis of this curve made it
possible to distinguish variations in the paleointensity with characteristic times of 5 and 1 Ma.
Comparison of the paleointensity variations with cycles of changes of the global sea level (cycles of
transgression ‒ regression or T‒R cycles) showed that these processes are interrelated. The T‒R cycles
data are taken from the Geologic Time Scale 2008. The paleointensity variations and changes of the
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global sea level with the same characteristic times occurred. In addition, a correlation relationship
between these processes was found. The increase in the amplitude of the paleointensity variations was
mainly due to the regressions of the global sea. Thus, the detected form of the connection between such
non-periodic processes as T‒R cycles and the paleointensity variations testifies that they are a reflection
of a single planetary process.
RESULTS OF MAGNETIC AND PALEOMAGNETIC INVESTIGATIONS OF
BABYI KAMEN’ SECTION, KEMEROVO REGION
D. Kuzina1, I. Gilmetdinov
1, R. Aupov
1, Yu. Balabanov
1, L. Kosareva
1, S. Zorina
1, V.
Silantiev1, V. Davydov
1, 2
1 – Institute of Geology and Petroleum Technologies, Kazan Federal University, Russia
2 – Permian Research Institute, Boise State University, USA.
In paper described investigations of the reference Permian-Triassic succession exposed in the Babyi
Kamen’ section in the left bank of the Tom’ River, Kemerovo region, Russia (54°23.079’N,
087°32.105’E). The samples collected within the Permian – Triassic transition. The thickness of
investigated interval is about 197 meters, we collected 77 oriented samples.
Magnetic susceptibility, hysteresis parameters, NRM measurements are carried out to determine changes
in magnetic mineralogy and sedimentation settings (or environments). For studying mineralogy were used
thermomagnetic analysis and petrographic analysis. It is shown that magnetite and hematite are the main
carriers of magnetization in the studied rocks. The pyrite content in the samples is very low according to
petrographic analyses and mapping Fe and S in the polished sections.
Thermomagnetic demagnetization have been made for all collection and have been measured with a
Cryogenic (SQUID) magnetometer 2G Enterprises (USA) located in a nonmagnetic room in the
Laboratory of the Main Geomagnetic Field and Petromagnetism of the IPE RAS, Moscow. Some samples
heated up to 680 °C depending on magnetization loss.
Changes in polarity of magnetic field are also detected. Along the succession magnetic pole changes
several times. According to magneto-mineralogical and lithological data some of the changes detected in
the lower part of the section depend on environmental conditions of sedimentation.
This work was funded by the subsidy 5.2192.2017/4.6 allocated to Kazan Federal University for the
state assignment in the sphere of scientific activities.
EARTH’s CRATER MAGNETIC ANOMALIES: NUMERICAL MODELING
OF SIMPLE CRATERS
M. Yu. Kuzmicheva
Institute of Geospheres Dynamics RAS
Numerical simulations are quite successful reproducing the crater morphology, but it was not yet widely
possible to model the crater negative anomaly.
83
As known a crater-forming impact alters the magnetization of the crust by way of excavation and mixing
of target material, by thermal demagnetization (and following re-magnetization if possible), by shock
demagnetization [1,2].
Heated in the impact, magnetic minerals in the crust cool below their Curie temperatures and acquire a
thermo-remnant magnetization (TRM) with a magnitude proportional to the strength of the ambient
magnetic field. Magnetic materials can be magnetized in an external magnetic field through shock
remnant magnetization (SRM). Existing magnetization can be reduced or erased if the minerals are
shocked in an ambient field too weak to induce a sufficient SRM. Post-impact hydrothermal system can
lead to further TRM and/or the acquisition of chemical remnant magnetization (CRM).
Generally, craters are characterized by circular magnetic low and short-wavelength intense anomalies
produced by impact melt sheets and/or suevite deposits. Transient and final crater diameter dimensions
are critical for estimations of energy released in impacts. Magnetic survey data show that disruption
cavity size can be inferred from magnetic anomaly character [3].
Due to plate tectonics the present geomagnetic field at the crater location differs of this one at epoch
when the primary crust was created, as well as of the field of the impact time. These differences exhibit in
twist of cavity and melt dipoles.
In presented work three-dimensional magnetostatic calculations of crustal magnetic field of simple craters
have been performed.
Magnetic properties of rocks in simulations were determined according [4].
After-impact magnetic anomalies associated with a magnetic cavity, with a melt sheet have been
simulated, a relation of a magnetic low and crater transient diameter was determined.
References: 1. Artemieva N. et al. (2005) GRL, 32, L222041 .2. Ugalde H. A. et al. (2005) Geological
Society of America Special Papers, 384, p. 25-42. 3. Pilkington M. and Grieve R. (1992) Reviews of
Geophysics, 30, p. 161-181. 4. Plado J. et al. (1999). Geological Society of America. Special paper 339:
p. 229-239.
ANISOTROPY OF MAGNETIC SUSCEPTIBILITY IN THE PERMIAN-
TRIASSIC INTRUSIONS FROM THE NORTHWESTERN SIBERIAN
PLATFORM: IMPLICATIONS FOR THE MAGMA TRANSPORT PATTERNS
Latyshev A.V.1,2
, Ulyahina P.S.2, Krivolutskaya N.A.
3
1 – Lomonosov Moscow State University, Geological Faculty
2 – Schmidt Institute of the Physics of the Earth, Moscow
3 – Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow
The Siberian Traps LIP is considered to be the most voluminous region of intraplate magmatic activity in
Phanerozoic. Despite the continuous investigation, the detailed reconstructions of the magma transport
patterns during the Siberian Traps emplacement are scarce. According to the most popular model, the
plume head was located beneath the northwestern Siberian platform, in the Norilsk region. Recent studies
show that the lateral magma transport via the system of large and extent shallow sills was the important
feature of magmatic activity. In our previous work, we obtained the similar pattern based on the detailed
study of the anisotropy of magnetic susceptibility (AMS) in large sills of the Angara-Taseeva basin.
Here we present the results of the detailed investigation of AMS in the intrusions from the Norilsk and
Kulumbe districts (northwestern Siberian platform). These areas are located near the supposed center of
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LIP and inherit the Precambrian Norilsk-Igarka paleorift zone. For the reconstruction of the magma flow
direction we used the intrusions with the N-type of magnetic fabric, when the minimal axis K3 of AMS
ellipsoid is orthogonal to the intrusion contact. In this case, the lineation of the maximal axis K1 was
interpreted as the magma flow direction. The NW–SE magnetic lineation is the most common both in
Norilsk and Kulumbe sill-like intrusions. Thus, magnetic lineation is almost normal to the regional fault
zones of the NE strike, namely Norilsk-Kharaelakh and Imangda-Letninskiy faults. We suggest that
during the Siberian Traps emplacement magma ascended through the weakened zones, and moved
laterally from them in the shallow crust levels. Our scheme is consistent with the widespread idea about
the magma-feeding role of the Norilsk-Kharaelakh fault. Thus, this pattern of magma flow transport
controlled by the long-lived faults system is quite different from the fan-like distribution of thick sills
dominating the magma flow in the Angara-Taseeva basin.
This work was funded by RFBR projects 16-35-60114, 17-05-01121, 18-05-70094.
PALEOPROTEROZOIC TRENDS OF REMAGNETIZATION FOR THE
KARELIAN CRATON: MYTH OR REALITY
Lubnina N.V., Tarasov N.A., Zakharov V.S.
M.V. Lomonosov Moscow State University, Faculty of Geology
Traditionally, during more than 20th-year paleomagnetic studies of Archean and Early Paleoproterozoic
complexes of the Karelian craton (Fennoscandia), the stable component of the northwestern directions
with moderate-steep downward inclinations is observed in the mid- and sometimes in the high
temperature/coercivity intervals. It is commonly referred to as 'the Svecofennian remagnetization’ or
overprint and dated as ~1.8 Ga.
At the same time, in different parts of the Karelian craton, mean directions of these secondary
components vary from each other and are dispersed, forming regular trends. These trends correlates
within the accretion Svecofennian or collisional Lapland-Kola orogens, and also the Belomorian mobile
belt. Usually they dated as 1.80–1.70 Ga, 1.95–1.90 Ga and 1.95–1.85 Ga respectively. However, in the
border areas of these orogens clearly identify the trend of remagnetization is not always possible.
Another important aspect of the research is to establish a correlation between remagnetization processes
and composition of the rocks. Probably varies of early and late secondary components is caused not only
with protolithic composition but also with different transformations of the rocks including whose fluid
saturation and fracturing. In other words, natural trends are not a consistent rejuvenation / ancientness of
the remagnetization within a whole orogen associated with the orientation of collision or accretion, but
only the result of uneven changes (remagnetization) of different composition rocks.
Moreover, for the Karelian craton, the position of different age Precambrian paleomagnetic poles often
coincides with each other or with the poles of Precambrian or Phanerozoic remagnetization several times.
At that, for all these poles, the primary origin of the high-temperature components is proved based on the
positive paleomagnetic reliability tests (mainly contact test). It is planned to discuss whether such
coincidences are evidence of the stable position of the Karelian craton in a particular part of the globe, or
whether there is a result of a one-time Phanerozoic (?) remagnetization that is not reflected in
paleomagnetic reliability tests.
This is a contribution to the project RSF 18-05-00170.
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KEY EARLY PALEOPROTEOROZOIC 2.45 GA PALEOMAGNETIC POLE
FOR THE KARELIAN CRATON: FURTHER PALEOMAGNETIC EVIDENCE
Lubnina N.V., Tarasov N.A.
M.V. Lomonosov Moscow State University, Faculty of Geology
We present a new paleomagnetic data from the Early Paleoproterozoic layered gabbronorite intrusions
and mafic dykes and Archean host rocks within two terranes of the Karelian Craton, eastern
Fennoscandian Shield. Early Paleorproterozoic Burakovka and Kivakka layered gabbronorite intrusions
have been collected at Vodlozero and Central Karelian terranes respectively. Three groups of dykes have
been collected within Pyaozero area of Central Karelian terrane: NEtrending ca. 2.45 Ga gabbronorite
and diorite dykes, NW-trending ca. 2.4 Ga dolerite dykes (Stepanova et al. 2014). We also sampled
Sariolian (ca 2.3 Ga) conglomerates containing pebbles both Early Paleozoic gabbronorites and
NeoArchean granites at Vodlozero terrane.
All studied samples from the Early Paleoprotrozoic layered intrusions and mafic dykes carried two stable
components. Most typical is component of intermediate down to the NNW, corresponds to the
Svecofennian remagnetisation (Mertanen et al. 1999). Component of SE intermediate down direction
yielding a paleomagnetic pole 2.45 Ga based on a positive baked contact test is interpreted to represent
the primary magnetization.
In the Sariolian conglomerates two remanence components were isolated in both in the gabbronorite and
granite pebbles. Stable mid-temperature components were removed in fields up to 20-40mT, and in
temperatures up to 540°C, after which scattered component were disclosed in high fields/temperatures.
Mid temperature component demonstrate northwestern directions with moderate downward inclinations,
close to the mid-temperature/coercivity components in mafic dykes and correspond to the Svecofennian
age remagnetization (negative conglomerate test). The high-temperature component isolated in both
gabbronorites and granites has a chaotic distribution on the sphere. The high-temperature/coercivity
component isolated in both gabbronorites and granites has a chaotic distribution on the sphere (positive
conglomerate test). This only shows the partial remagnetization of rocks in Svecofennian time (ca 1.8
Ga), while the high temperature component has a primary origin.
We propose a new Early Paleoproterozoic paleogeography at 2.45 Ga for the Karelia and Superior craton.
This is a contribution to projects RFBR 17-05-01270.
EXPERIMENTAL MODELING OF CHEMICAL MAGNETIZATION IN
OCEANIC BASALTS AND ITS PROPERTIES
Maksimochkin V.I., Grachev R.A., Tselebrovskiy A.N.
Lomonosov Moscow State University, the Faculty of Physics
During chemical transformations of minerals in the Earth's magnetic field, chemical remanent
magnetization (CRM) can be formed, which interferes with the solution of paleomagnetic problems. The
study of the properties of an artificially created CRM shows that there are conflicting data on the
separation of CRM and TRM in rocks [Maksimochkin et al., 2015; Gribov et al., 2017].
To develop criteria for the recognition of CRM in NRM, an experimental simulation of CRM on the
basalts samples of the Red Sea P72-2 and P72-4 and the study of its properties were carried out.
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According to electron microscopy and thermomagnetic analysis, the magnetic mineral of these basalts is
titanomagnetite with a magnetite consentration of 44.7% and 50.1% and Curie temperatures Tc=222±5°C
and 258±10°C, respectively. The grains of the titanomagnetite of the dendritic structure in the initial state
are homogeneous, the composition is close to the stoichiometric, the domain structure according to [Day
et al., 1977] corresponds to the pseudo-single-domain state.
Studies of samples annealed at temperatures Tan=290–535°C for 10 hours made it possible to distinguish
two processes of transformation of the initial titanomagnetite. The first process was observed at annealing
temperatures of 290–410 °C. It was characterized by an increase in the magnetic susceptibility and
saturation magnetization by 1.5–1.6 times, an increase by 13–14% of the remanent saturation
magnetization and a 10–15 % decrease in the magnetic stiffness, and also the inhomogeneity phase state,
which was probably due to the heterogeneity of the oxidation of grains of different sizes.
Annealing of the samples at 350 °C showed that saturation magnetization reached a maximum value after
holding for 40.5 hours. With increasing dwell time the contribution to the saturation magnetization of the
magnetic phase with a lower Curie temperature decreases. After annealing for t=40.5–110 hours, the
thermomagnetic analysis showed the presence of one magnetic phase with Tc=490–510 °C. A distinctive
feature of this process of transformation of titanomagnetite is its reversibility: heating of samples in an
argon medium up to 600 °C led to homogenization of oxidized titanomagnetite.
It is shown that an increase of the annealing temperature to T=460–535 °C, as well as an increase of
annealing time up to 350 hours at T=350 °C, leads to changes in the magnetic properties of
titanomagnetite, characteristic of oxy-decomposition. The restoration of the initial state of titanomagnetite
after heating the samples to 600 °C in argon was not carried out in this case.
It was found that CRM, measured at room temperature, increases with the annealing time by a law close
to exponential, and reaches saturation at t=40 hours. The ratio of the partial thermoremanent
magnetization (PTRM) formed in the temperature range from Tc to the annealing temperature decreases
from 1.3–1.4 for t=4.5 hours to 0.93 for t=110 hours.
Studies have shown that the properties of CRM and PTRM (Tc–Tan) approach each other with increasing
oxidation state. With a high degree of oxidation of titanomagnetite, CRM can be identified as TRM. An
indicator that the NRM in basalts in this case is CRM can be a significant decrease in the Curie
temperature of the samples after heating them in an argon medium to 600 °C.
In the middle stage of single-phase oxidation, the chemical and PTRM at T>Tan have practically identical
spectra of blocking temperatures and differ significantly at T<Tan. Obviously, in this case, CRM and
TRM in basalts can be recognized.
DETERMINATION OF PALEOINTENSITY OF GEOMAGNETIC FIELD ON
THE VOLCANOES LAVAS OF KAMCHATKA
V.I. Maksimochkin1), Yu.V. Sleptsova1)
, A.N. Nekrasov2)
1-Faculty of Physics Lomonosov Moscow State University
2-Institute of Experimental Mineralogy RAS
[email protected], [email protected]
Five samples of lavas of volcanoes of Kamchatka were investigated: 3 samples from the Avachinsky
volcano and 1 sample from the Gorely volcano - no more than 8000 years old, 1 - from the lava flow of
the Tolbachik volcano eruption in 2012.
Thermomagnetic analysis carried out on the dependence of the magnetization in the field of 0.24T and the
initial magnetic susceptibility on temperature showed that the titaniferous magnetite with the Curie
temperature Tc=540÷580°C is the mineral responsible for the magnetic properties of the Avachinsky
87
volcano samples. The investigation of the grains of ore minerals in electron and magnetic-force
microscopes revealed the presence of signs of high-temperature oxidation of titanomagnetite. The Curie
temperature of the samples from Gorely and Tolbachik volcanoes was Tc=250-310°C.
The paleointensity value Hdr=56µT, determined from the NRM of sample from the Tolbachik volcano
using the Telier-Coe procedures, was quite close to the value of the modern magnetic field in the region
of this volcano (НIGRF=53µT) according to the IGRF-12 model. It demonstrates the reliability of the
methodology we used to determine the paleointensity from the remanent magnetization of igneous rocks.
Age of the lava flow from the volcano Avachinsky was not known. The paleointensity values Hdr=50±4,
55±4, 58±6, determined from the samples from this volcano, were also quite close to the current value of
НIGRF =52µT for the location of this volcano. It is concluded that the age of the investigated lava flow
does not exceed 200 years.
For the sample from the Gorely volcano, the value Hdr=69±6µT and the calculated value of
VADM=10±0.9*1022
А*m2 indicate that the investigated rock refers to the outpouring of lava that
occurred 3-4 thousand years ago, which is in good agreement with the literature data on paleosecular
variations of the geomagnetic field.
The sample from Tolbachik volcano was not oriented. Investigating two samples from the Avachinsky
volcano we managed to obtain quite close values of the coordinates of the paleomagnetic pole 67N 142E
and 77N 133E. The limited data obtained did not allow to make a more unambiguous conclusion about
the coordinates of the paleomagnetic pole. The measured values of declination and inclination of the
remanent magnetization of one of the Avachinsky volcano samples indicate that the NRM was formed
when the lava flow moved.
INTERRELATIONS BETWEEN THE GRANULOMETRIC COMPOSITION,
MAGNETIC PROPERTIES AND GEOCHEMICAL INDICATORS IN THE
SUBAERIAL DEPOSITS OF THE ARCHAEOLOGICAL SITE "TUYANA"
(TUNKA DEPRESSION, BAIKAL REGION, RUSSIA)
Matasova G.G.1, Shchetnikov A. A.
2,3,4, Kazansky A.Yu.
5,6, Filinov I. A.
2,3,4
1- Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of
Sciences, Novosibirsk, Russia
2- Irkutsk State University, Irkutsk, Russia
3- Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences, Russia
4- Irkutsk Scientific Centre, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
5- Geological Department of Lomonosov Moscow State University, Moscow, Russia
6- Geological Institute of Russian Academy of Sciences, Moscow, Russia
The Tuyana section (51º42'N, 102º41'E) is located at foothills of Khamar Daban ridge, on the right bank
of the Irkut river. A unique multi-layer archaeological site of the Upper Paleolithic age was discovered
here in 2011. We present the analysis of correlation between granulometric composition, content of
oxides of various elements, geochemical indicators of climate and rock-magnetic characteristics.
The granulometric, chemical composition and rock-magnetic properties of sedimentary rocks are
influenced by the same factors: the chemical composition and genesis of rocks in the source, the type and
88
degree of weathering, the distance and the mode of transport, the post-sedimentation processes of
reworking of material in the sedimentation environment. Those transformations are resulted from
different climatic and physicochemical conditions of sedimentation.
In general, sand fractions on the one hand, are correlated with concentration-dependent magnetic
characteristics, on the other hand, with SiO2, Na2O, and in the lower part of the section, are additionally
correlated with MgO and K2O. The content of coarse silt fraction is almost constant all over the section,
but in its upper part it is connected with Na2O and CaO, while in the lower part with SiO2, MgO and K2O.
A small amount of magnetically hard minerals was recognized in the coarse silt fraction. Fine silt fraction
is closely related to Fe2O3 and PPP all over the section. In the upper part of the section the fine silt
fraction correlates with Al2O3 and Corg, in the middle part - with MgO, P2O5 and K2O and in the lower
part - with CaO, TiO2, MnO and Corg. The highest content of paramagnetic minerals contributing up to
33% to the total magnetism of the deposits is connected with silt fraction. Fine-grained fractions, clay and
mud, are correlated with LOI and Corg throughout the section, and additionally with Al2O3 and with
P2O5, K2O, CaO, TiO2 and MnO in the upper and middle. Fine-grained fractions contain OD and SPM
magnetic grains of authigenic origin. Climatic petrochemical indexes differently correlate with
granulometric fractions and magnetic characteristics, depending on the constituent oxides. The closest
correlations with rock-magnetic parameters demonstrate the following petrochemical modules: AM, NM,
NAM, ASM, K2O/Al2O3, (Fe+MnO)/Al2O3 and (Al2O3+Na2O+K2O).
This work was supported by the Russian Foundation for Basic Research (project no. 16-05-00586) and
Ministry of education and science of the Russian Federation (project no. 2017-220-06-1656).
PRELIMINARY ESTIMATION OF THE NON-DIPOLE PART OF THE
GEOMAGNETIC FIELD IN THE QUATERNARY PERIOD BASED ON THE
INVESTIGATION OF MARINE MAGNETIC ANOMALIES ON THE
CARLSBERG RIDGE
Merkuriev S.A.1,2
, Demina I.M.1, Ivanov S.A.
1
1 - Marine Geomagnetic Investigation Laboratory, SPbF IZMIRAN, St.Petersburg,Russia
2 - Institute of Earth Sciences St.Petersburg State University, St.Petersburg, Russia
One of the main principles of paleomagnetology, on which paleotectonic interpretation of paleomagnetic
data is based, is the hypothesis of a geocentric axial dipole, i.e., the time-averaged geomagnetic field is
well approximated by the field of a central axial dipole located in the center of the Earth and oriented
along its rotation axis. However, as more detailed studies have shown, the time-averaged field is largely
asymmetric and long-term deviations in the field geometry from the field of a geocentric axial dipole are
observed. A convenient method to study these effects is exploring of the inclination anomaly [Cox, 1975],
defined as the difference between the observed inclination and geocentric dipole inclination.
Marine magnetic anomalies are the records of the history of geomagnetic field reversals. In addition, the
shape of the magnetic anomalies depends on the effective inclinations of the ambient magnetic field and
the remanent magnetization vectors, and can be numerically expressed by the skewness (asymmetry)
parameter (theta). The paleomagnetic analysis of marine magnetic anomalies is based on the
determination of the parameter , which is usually performed by inverse phase filtration using the fast
Fourier transform for different shift parameters [Schouten, 1972; Schouten and McCamy, 1972].
Knowing values of allows us to find the remanent inclination and makes it possible to estimate the
contribution of the averaged non-dipole field.
89
We investigated several dozens of magnetic profiles crossing the axis of the Carlsberg ridge near the
equator which cover the axial anomaly (Crone C1n, the Brunhes normal polarity chron) and the adjacent
anomalies 2 (Olduvai C2n subchron of the Matuyama chron). A study of the anomalies along the axis of
the ridge showed that its shape varies significantly from profile to profile, which leads to a change in the
magnitude of the anomalous inclination.
The dispersion of the parameter for profiles located within the same segment, where the change in the
inclination can be neglected, is apparently related to the influence of the bottom relief and its
asymmetrical structure, reflecting the influence of tectonic irregularities both transversally and along the
ridge axis. In order to reduce the dispersion within each spreading segment, an algorithm for constructing
the averaged profile was used, for which the magnitude of the inclination anomaly was determined, which
made it possible to get more reliable .
The observed general increase in the inclination anomaly with decreasing latitude, testifies to the
predominance of the contribution of the quadrupole component (quadrupole sources) to the averaged non-
dipole field in comparison with the octupole field [Merrill and McElhinn, 1977].
Our estimates of the inclination anomaly are close to the estimates obtained from previous paleomagnetic
investigations of sediments in the Indian ocean[Schneider and Kent, 1988] and magnetic anomaly profiles
from the Galapagos Ridge [Schneider, 1988].
PRELIMINARY MAGNETIC INVESTIGATIONS OF LAKE BOLSHOE
MIASSOVO SEDIMENTS (CHELYABINSK REGION, RUSSIA)
D. Nurgaliev, D. Kuzina, P. Krylov, L Kosareva, V. Antonenko, P. Yasonov, A.
Yusupova
Institute of Geology and Petroleum Technologies, Kazan Federal University, Russia
During summer field trip was studied lake Bolshoe Miassovo, Chelyabinsk region, Russia (55°09.3’N,
060°17.1’E). The origin of the lake is tectonic. Lake sediments composition are small grained sands, silty
sand and black silt. Seismoacoustic investigations were carried out for choose the best places for coring
with continuous sedimentation and avoid gas saturated sediments. Overall 10 km of seismoacoustic
profiles obtained.
Long cores (up to 5 meters) were collected with using special hydraulic corer; short cores (up to 0.5 m)
sampled by gravity corer (UWITEC). Measurements of magnetic susceptibility (MS), hysteresis
parameters and thermomagnetic analysis were carried out to determine changes in magnetic mineralogy
and sedimentation conditions. Measurements were made in the paleomagnetic laboratory of Kazan
University. Thermomagnetic curves measured on Curie express balance, coercitive parameters on J-
coercivity spectrometer and magnetic susceptibility on multi-function kappabridge MFK1-FA (AGICO).
Changes in magnetic susceptibility in first 4.5 meters are not significant, which tells us about stable
conditions of sedimentation, below 4.5 meters there is rapid growth of MS.
This work was funded by the Russian Science Foundation under grant 18-17-00251.
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METHODOLOGY FOR LOW FLYING AEROMAGNETIC SERVICE WITH
THE USE OF UAV
Parshin A.V.1, Tsirel V.S.
2, Rzhevskaya A.K.
3
1 – SibGIS LLC, Vinogradov Institute of Geochemistry SB RAS, Irkutsk, National Reseach Technical
University, Irkutsk, Russia.
2 – Geologorazvedka JSC, Saint-Petersburg, Russia
3 – Fedorovsky Institute VIMS, Moscow, Russia
[email protected], [email protected], [email protected]
1. The idea to use unmanned aviation vehicles (UAV) for aeromagnetic surveys first was put forward first
in Australia and Russia in 1995. At present there exist four most successful groups which use this
method: in Irkutsk (headed by A.V. Parshin); in Saint Petersburg a group of companies “Geoscan”,(
headed by A.E. Semenov) and NPP “Radar MMC” (headed by V.G. Ancev, scientific consultant V.S.
Tsirel); in Novosibirsk INGG SB RAS headed by the director of the Institute M.I. Epov.
2. On the basis of their experience a document “Recommendations for low flying aeromagnetic surveys
with the use of UAV” was issued on the initiative of VIMS (Moscow). The “Recommendations” were
first discussed and later approved by “Rosnedra”. The minutes states that the new method is “… the most
rational one in geological prospecting”. So the new method is officially approved.
3. The “Recommendations” treat on the main problems (the most important ones from the point of view
of the authors) which are crucial for the adoption of the method. These are, namely, role and place of low
height aeromagnetic surveys in the structure of geological prospecting methods; enumeration of existing
complexes for low height aeromagnetic surveys. They give a list of survey scales; evaluation of the
measurement grid density; classification of surveys according to measurement precision (which
introduces a new criterion – precision surveys with the error less than 1 nT, role of the wrong placement
of measurement system (as a whole) in the standard error. Special parts are devoted to magnetic
variations role in working out a time system for the whole of used apparatus; experience measurements
on the plot; provision of topography-geodetic data for a particular flight.
4. The main idea is as follows: the “Recommendations” are, in fact, the only official document
supplementing the existing and regulating “Instruction on magnetic measurements” (Leningrad, “Nedra”,
1981, 263 p.). Creation of a new geophysical method makes it possible to change the order of geological
prospection stages in the nearest future.
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PALEOMAGNETISM OF THE UDZHA AND OLENEK UPLIFTS,
NORTHERN SIBERIA
Pasenko A.M.1, Malyshev S.V.
2
1 – The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow,
123242, Russia
2 – Institute of Earth Sciences, St. Petersburg State University, 7/9 University Nab., St. Petersburg,
199034, Russia
In spite of the fact, that during the last two decades some number of new paleomagnetic poles, more or
less meeting the modern standards of quality [Van der Voo, 1993], have been obtained for
Neoproterozoic of Siberia [Metelkin et al., 2016, 2010, Pavlov et al., 2015], the problem of the
Precambrian segment of the apparent polar wander path (APWP) for Siberia, rests still to be far from its
solution.
The latter, obviously, hampers the elaboration of Precambrian paleogeographic reconstructions, solution
of numerous other important tasks of the Earth Sciences.
The Late Precambrian key section of the Udzha Uplift seemed to be one of the most promising object to
elaborate the Neoproterozoic segment of APWP of the Siberian platform. Until recently, the rocks
composing this section have been considered to be of the Mesoproterozoic, Neoproterozoic and Vendian
age.
As a result of isotope studies in recent years, the age of formations of the Udzha Uplift has been
significantly increased [Gladkochub et al., 2009]. In particular, age of the Udzha Fm, which forms the
uppermost part of the Udzha riphean sequence is considered currently to be Mesoproterosoic. On the base
of our new paleomagnetic data this formation has been formed about the same time as the Khaypakh Fm
from the Olenek Uplift (NE Siberia), whose Mesoproterozoic age has been established earlier from
independent isotopic data [Zaitseva et al., 2017].
During last several years we have carried out the paleomagnetic studies of Late Precambrian rocks of the
Udzha Uplift including the Mesoproterozoic Udzha and Unguokhtakh formations as well as intrusions
representing two Mesoproterozoic magmatic events.
As a result of these studies the series of new Mesoproterozoic Siberian paleomagnetic poles has been
obtained. These paleomagnetic poles significantly complement the Mesoproterozoic segment of APWP of
the Siberian Platform.
The research was supported by grant of the Russian Ministry of Education and Science
14.Z50.31.0017.
92
METALLIC IRON IN BASALTIC LAVA RIVER FROM MALY YENISEI
(TUVA, RUSSIA): THE RESULTS OF THERMOMAGNETIC STUDY
Pechersky D.M.1, Kazansky A.Yu.
2, 3, Kozlovskiy A.M.
4, Kuzina D.M.
5, Markov G.P.
1
1 Schmidt Institute of Physics of the Earth RAS, Moscow, Russia
2 Geological Department of Lomonosov Moscow State University, Moscow, Russia
3 Geological Institute RAS, Moscow, Russia
4 Institute of Geology of ore deposits, petrography, Mineralogy and Geochemistry RAS,
Moscow, Russia
5 Kazan (Volga Region) Federal University, Kazan, Russia
We present thermomagnetic results on 6 lava flows from Maly Yenisei lava river (51.4 N, 91.4 E) in Tuva
region, Russia. The study was carried out in IPE RAS Moscow and Kazan University, Kazan.
Titanomagnetite with Curie points 100-120 C° was found as a main magnetic mineral in basalt of lava
river. Titanomagnetite is partly undergone heterophase oxidation up to magnetite in some samples. Iron
concentration in basalt is rather low and varies from 0 to 0.210-3
%. It should be noted that samples where
titanomagnetite is completely oxidized to magnetite the native iron is also absent due to the intensive
oxidation. Due to Curie points >760°C the iron in Maly Yenisei basalt is close to pure iron similarly all
the other terrestrial and lunar objects. The Curie points of 775 ° C and above in Maly Yenisei most likely
are due to a small admixture of cobalt in the iron.
Metallic iron particles must sink down inside liquid basaltic lava flow, so the iron concentration should
increase from top of the flow towards its bottom. Such clear tendency in downwards increase od Fe
concentration is observed in flows 1, 3, 5, while in flows 4, 6 it is perturbed and completely absent in
flow 2. The perturbations in Fe concentration most likely are caused by turbulent motions inside the flow
and low content of metallic iron. However, the rates of downward increase of Fe concentration in flows 1,
3, 5 are very close.
Despite wide variation of native iron concentration in different types of basaltic lava (Maly Yenisei lava
river, lava river from East Sayan, ocean floor basalts and Siberian traps) the size of the iron particles is
practically the same in all cases (similar histograms of iron particle distributions with modes 10–20 µm).
This can be explained only by one determining factor - the gravity of the Earth. Therefore, according to
the histogram of the size of iron particles, you can try to restore the magnitude of gravity, more precisely -
the acceleration of gravity, and hence the mass of the planet.
93
THE AVERAGE SIZE OF IRON PARTICLES VS. THE AGES OF LUNAR
BASALTS
D.M. Pechersky, G.P. Markov
Schmidt Institute of Physics of the Earth RAS, Moscow, Russia
Тhe micro-photographs of thin sections of lunar basalt brought to Earth by American spacecraft "Apollo
11-17", was measured the grain size of iron in lunar basalts, with absolute radioisotope Dating. As a
result, as seen in Fig. 1, an obvious dependence of the average size of such grains on the age of basalts
was found, namely, in the time interval from 3.9 to 3.2 billion years ago. Only two samples deviate from
this dependence. The average grain size increased by about 1.6 times (Fig.1), which may indicate, in
particular, a significant decrease of the acceleration of gravity on the Moon for the same period of time.
Fig. 1. Dependence of the average grain size of "iron" D (µm) in lunar basalts vs. the age of basalts.
Hollow diamonds - photo of thin section in transmitted light; filled diamonds in the reflected light.
Since the dependence of the grain size on the age of the basalts is, at least for the moon, global in nature,
the decrease in the lunar acceleration of gravity can be associated either with an increase in the size of the
moon, or with a decrease in its mass, or with both, together. It is impossible to exclude also such, the most
courageous, the most nontrivial and the most improbable option as change in time of a gravitational
constant.
94
PETROMAGNETIC AND MICROPROBE STUDIES OF PEAT DEPOSITS
(PRELIMINARY RESULTS)
Peskov A.Yu.1, Chakov V.V.
2, Klimin M.A.
2, Krutikova V.О.
1, Zakharchenko Е.N.
2,
Arkhipov М.V.1, Didenko А.N.
1,3
1 Kosygin Institute of Tectonics and Geophysics, Far Eastern Branch, Russian Academy of Sciences,
Khabarovsk
2Institute of Water and Ecology Problems, Far Eastern Branch, Russian Academy of Sciences,
Khabarovsk
3 Pacific National University, Khabarovsk
Preliminary results of petromagnetic and microprobe studies of peat samples from the stratified section
located on the marshy watershed between the Khor and Kia rivers (Khabarovsk krai) are presented.
The section is represented by woody grass dark brown peat. Marsh formation took place early in the
boreal period about 9000 years ago (radiocarbon analysis – 8890±95 years). The programme of
continuous sampling along the 190-cm-thick section included collection of 95 oriented samples. The
initial magnetic susceptibility (ϰ) was measured by a Kappa-Bridge MFK-1FA magnetic susceptibility
meter (sensitivity 2E-8 SI units). Microprobe studies were performed using a scanning electron
microscope VEGA3 LMH fitted with energy dispersive X-ray spectrometer X-Max80.
In the course of petromagnetic studies, 3 horizons characterized by an enhanced initial magnetic
susceptibility were established: 0-10 cm horizon (mean – 2.13E-06 SI units); 52-56 cm horizon (1.71E-06
SI units); and 176-190 cm horizon (1.44E-05 SI units). The mean ϰ value for the entire section is 2.30E-
08 SI units.
Microprobe studies showed that magnetic minerals in samples from the established intervals are clastic
particles of titanomagnetite and hemoilmenite series. Particles vary in size from 2 to 200 μm. Magnetite
globules from 6 to 14 μm in size (presumably of space origin?) are recognized in the 52-56 cm and 176-
190 cm horizons. In the 0-10 cm and 52-56 cm horizons, spherical forms of carbon of unknown origin
measuring from 2.53 to 2.81 μm are found.
Thus, most probably particles in the 52-56 cm horizon are from outer space. Anthropogenic sources can
account for elevated ϰ values in the 0-10 cm horizon as a result of initial development of the peat bog.
The confinement of the 176-190 cm horizon to the contact zone between the overlying peat and the
underlying clay minerals does not allow a definitive conclusion to be made as to the reason of enhanced
magnetic susceptibility in it.
The study was carried out with the financial support of project No. 112/2018D.
95
PALEOMAGNETISM OF THE PIONERSKAYA FORMATION;
CONTRIBUTION TO THE GEODYNAMIC MODEL OF THE SIKHOTE-ALIN
OROGENIC BELT
Peskov А.Yu.1, Arkhipov M.V.
1, Kudymov A.V.
1, Didenko A.N.
1, 2
1 Kosygin Institute of Tectonics and Geophysics, Far Eastern Branch, Russian Academy of Science,
Khabarovsk
2 Pacific National University, Khabarovsk
The study focused on the Berriasian-Valanginian sandstones of the Pionerskaya Formation (54.09ºN,
140.05°E). Structurally, these rocks belong to the Zhuravlevka-Amur terrane (Khanchuk, 2006, and
others), also known as the Amur terrane (Zyabrev, 2011, and others), of the Sikhote-Alin orogenic belt,
where it borders on the Mongol-Okhotsk orogenic belt. There are various tectonic zoning maps of, as well
as geodynamic models for evolution of the Mongol-Okhotsk and Sikhote-Alin orogenic belts, which
differ appreciably (Parfenov et al., 1999, Khanchuk, 2006, Golozubov, 2006, and others). One of the main
reasons for this is the almost total absence of paleomagnetic data making it possible to quantify the
kinematics of the motion of terranes that make up the orogenic belts.
Paleomagnetic studies (AF demagnetization using a 2G Enterprises SQUID magnetometer 755-R) gave a
pre-folding (Ks/Kg=6.4) component of magnetization. The average value of natural remanent
magnetization (NRM) of the samples studied is 1.4E-03 A/m and magnetic susceptibility (ϰ) is 1.37E-04
SI. The average anisotropy of initial magnetic susceptibility (AMS) is 2.1%. No dependence for AMS and
km is found suggesting either the absence or minor influence of secondary processes on the magnetic
fabrics in sandstones. Considering the AMS data, calculation of inclination shallowing according to
(Bradbury, 2005) yielded ≈7 °. The following coordinates of the ancient component of magnetization
were used to calculate the paleomagnetic pole: Decs=305.5°, Incs=34.9°, Ks=11.6, a95s=10° (statistics by
samples – N=20). Coordinates of the paleomagnetic pole were: Plat=36.0°, Plong=32.0, dp=6.6°,
dm=11.5. The results of the study on the Berriasian-Valanginian sandstones of the Pionerskaya Formation
in the northern Sikhote-Alin orogenic belt indicate that they formed at the latitude of 19.2º±6.6ºN
meaning that later they moved more than 3 500 km northward along the Eurasian margin.
This study was supported by the Russian Science Foundation (project no. 16-17-00015).
MAGNETIC PROPERTIES OF SEDIMENTARY ROCKS FROM
PIONERSKAYA AND GORINSKAYA FORMATIONS (JUNCTION ZONE
BETWEEN THE SIKHOTE-ALIN AND MONGOL-OKHOTSK OROGENIC
BELTS)
Peskov A.Yu.
Kosygin Institute of Tectonics and Geophysics, Far Eastern Branch, Russian Academy of Sciences,
Khabarovsk
The junction zone between the two orogenic belts in question is represented by Upper Triassic, Lower-
Middle Jurassic turbidites of the Ulban terrane and Cretaceous rocks of the Zhuravlevka-Amur turbidite
basin. Sandstones of the Gorinskaya and Pionerskaya formations of the Komsomolskaya Group collected
96
in exposed outcrops of Sakhalin Bay were studied. Structurally, these rocks belong to the Zhuravlevka-
Amur terrane. The Gorinsky Formation is dominated by sandstones (1100-1300 m); siltstones and their
flyschoid interbedding are rare. Its age determined from Buchia-bearing parts is restricted to the
Berriasian. Based on Buchia, the overlying Pionerskaya Formation (900-1430 m) is assigned to the
Berriasian-Valanginian (Kaidalov et al., 2009).
Studies have found that magnetic properties of sandstones from the Pionerskaya and Gorinskaya
formations differ appreciably. Mean values of natural remanent magnetization (NRM) differ by more than
two orders of magnitude: 1.4E-03 A/m (Pionerskaya Fm) and 3.31E-01 A/m (Gorinskaya Fm). Mean
susceptibility (ϰ) values of studied specimens of rocks from the Pionerskaya and Gorinskaya formations
are 1.37E-04 SI and 2.98E-04 SI units. Hysteresis parameters were also studied. The average ratios of the
hysteresis loop parameters for sandstones of the Pionerskaya Formation are: Irs/Is=0.003; Hcr/Hc=13.2.
Data points of rock specimens from the Pionerskaya Formation fall in the multi-domain (MD) particle
field on the modified Day’s plot (Dunlop, 2002). Sandstones of the Gorinsky Formation show higher
magnetic rigidity than rocks of the Pionerskaya Formation. Their data points plot within the pseudo-single
domain (PSD) field - the average values of hysteresis parameters ratios are: Irs/Is=0.14; Hcr/Hc=1.8.
The results obtained can be used in paleomagnetic studies, and also as a petrophysical criterion for
differentiating rocks during geological surveys.
The reported study was funded by RFBR (project no. 18-35-00048).
IDENTIFICATION OF MAGNETIC CHRONS BY COMPONENTS OF
MARINE BAND ANOMALIES
A.A.Petrova, Yu.A.Kopytenko
SPbF IZMIRAN, St-Petersburg, Russia
It is presented the component model of the Earth's magnetic field (EMF) developed by SPbF IZMIRAN
and its application for the identification of sea band alternating anomalies of components. It is considered
in order to clarify the reconstruction of tectonic plates, study the nature of changes in the components of
the EMF vector for the periods of EMF inversion during the formation of the seabed and study the
structure of the Earth's crust of the oceans. The component model of EMF is constructed from the results
of vector surveys and values of components calculated from measurements of the absolute vector of the
magnetic field induction near the Earth's surface. For the water areas of the North Atlantic and North-
West Pacific, models of sea linear anomalies of horizontal H and vertical Z components have been
constructed that provide the additional information for reconstructions of the formation of the oceanic
crust and the space-time displacements of tectonic plates.
97
ARHEOMAGNETIC STUDIES OF NEOLITHIC CERAMICS OF VEKSA
ARCHEOLOGICAL SITE (CONTINUATION)
Pilipenko O.V., Nachasova I.E., Markov G.P.
Schmidt Institute of Physics of the Earth RAS, Moscow, Russia
This work is a continuation of arheomagnetic studies of ceramics of archaeological complex Veksa in
order to obtain data about the geomagnetic field intensity in the Neolithic in the center of the Russian
Plain. The archeological complex Veksa is located about 20 km north-east of Vologda town (59.2o N,
39.9o E). The thickness of the cultural layers is about 50 m. 41 samples of ceramics were investigated.
Burned materials are fragments of pottery, whose color varies from light brown to dark brown. The age of
fragments of pottery was determined from C14
method [Nedomolkina, 2004]. Laboratory studies were
carried out using the modified double heating Tellier method [Thellier, Thellier, 1959; Coe, 1978] with
the control of possible changes in the ability of the sample to acquire a thermal remanent magnetization
by measuring the so-called pTRM check-points and pTRM tail-checks. We used for paleointensity
estimations only that points, when difference between tail-check and NRM was less than or equal 10%
and when difference between check-point and pTRM was less than or equal 10 %. As a result of the
studies data about the change of the geomagnetic field intensity recorded in the fragments of ceramics of
the archeological complex Veksa in the ~6200-2000 yr BC were obtained. The geomagnetic field
intensity in this time interval varies in the range of 20-65 μT and reached the highest values in the last
quarter of the V millennium B.C. The obtained data are in good agreement with the data obtained in
archaeological monument Sakhtysh.
This work was supported by the State Task of IPE RAS, RFBR (project no. 16-05-00378) and by the
Government of the Russian Federation (project no.14.Z50.31.0017).
References
Coe R.S. Geomagnetic paleointensity from radiocarbonated flows on Hawaii and the question of the
Pacific nondipole low // J. Geophys. Res. 1978. V. 83. P. 1740-1756.
Nedomolkina N.G. Neolithic complexes of the settlements of Veksa and Veksa 3 of the upper Sukhona
basin and their chronology // Problems of chronology and ethno-cultural interactions in the Neolithic
Eurasia. S.-P. 2004. V.2. P.265-279.
Thellier E., Thellier O. Sur l’intensité du champ magnéttique terrestre dans le passé historique et
géologique // Ann. Geophys. 1959. V. 15. Pp. 285-378.
98
NEOPROTEROZOIC GLACIAL DEPOSITS OF SIBERIA: THE PROS AND
CONS OF SNOWBALL EARTH HYPOTHESIS
Andrey Shatsillo1, Dmitriy Rudko
1, Sergey Rudko
2,3, Irina Latysheva
2, Nikolay
Kuznetsov2
1Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences
2Geological Institute, Russian Academy of Sciences
3Institute of Precambrian geology and geochronology, Russian Academy of Sciences
Lots of paleomagnetic data shows a low-latitude position of ancient platforms during Neoproterozoic
glaciations. In terms of the "Snowball Earth" hypothesis it means, that during this time Earth was totally
covered by ice few times. Theoretical calculation shows inevitable closure of polar ice-caps after they
reach near 300 latitudes in response to the positive feedback loop between thermal balance and albedo of
planet. However, there are no paleomagnetic data showing a high-latitude position for some continent at
this time. It can be explained by absence of continental blocks in high latitudes, or by development of
glaciations only in low latitudes. The latter is developed in G. Williams' "anti-Snowball" works and can
be explained by the dramatic change of the Earth's obliquity angle.
In Neoproterozoic sedimentary sequences of Siberia few glacial horizons are known, and their origin is
believed to be related with global glaciations. For two of them, we obtained paleomagnetic data indicating
the low-latitude position of the Siberian platform during glaciation. Particularly calculated paleolatitude
for overlapped by tillites Vandadyk fm. is ~ 90. Paleolatitude for Nichatka fm. containing glacial deposits
is ~ 00. Such results are “pros” for “Snowball Earth” hypothesis from one hand. From another hand the
results from Nichatka fm. are obtained in deposits resembled modern varves (seasonal-controlled
periglacial deposits). We argue this type of varves cannot be formed nor in equatorial areas, nor under
global-glaciation conditions. Therefore, the obtained data finds no explanation in terms of “Snowball
Earth” hypothesis and may indicate inconsistency of Geocentric Axial Dipole model for Neoproterozoic
geomagnetic field.
Sedimentological studies are supported by the RSF grant 18-77-00059 and paleomagnetic researches are
supported by grant 17-05-00021 from the Russian Foundation for Basic Research.
CYCLOSTRATIGRAPHIC ANALYSIS OF LOPATA FORMATION (NE OF
ENISEY RIDGE, WESTERN SIBERIAN PLATFORM): MORE ON
HYPERACTIVITY OF GEOMAGNETIC FIELD IN THE LATE
PRECAMBRIAN
Dmitriy Rudko1, Sergey Rudko
2, Andrey Shatsillo
1, Nikolay Kuznetsov
2
1 Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences
2 Geological Institute, Russian Academy of Sciences
Recently geomagnetic field hyperactivity has been suggested for the Terminal Ediacaran and its impact
on the Cambrian explosion of Life has been supposed [Meert et al., 2016]. The suggestion of
99
hyperactivity is based on the unusually high amount of magnetic polarity zones recorded in some late
Ediacaran rocks of Baltica and Siberia. However, quantitative estimates of geomagnetic field reversal
frequency have not yet been presented. In Siberia, an anomalous magnetostratigraphic record was
detected in the Lopata Fm. redbeds (Yenisei Ridge). Here 58 zones of magnetic polarity were recorded in
a 60 m sedimentary sequence.
To determine the frequency of magnetic field reversal, the accumulation time of the Lopata Fm. deposits
were studied using sedimentological and cyclostratigraphic approaches. The depositional settings of the
Lopata Fm. were interpreted as analogues of the wadi channels in modern deserts, which can provide
sedimentation rates as low as 0.2 m/1000 years. To estimate the duration of the formation of the sequence
examined by the cyclostratigraphic method, magnetic susceptibility (MS) was measured along a section
with a step of 0.2 m in the field. According to sedimentological estimates, such measurement frequency
should be enough to recognize precession, obliquity and eccentricity astronomic cycles possibly affecting
the magnetic characteristic of the rock.
The multi-taper spectral analysis of measured MS variations shows a number of peaks on the
periodogram which correspond to significant periods of 29.3, 7.1, 1.8, 1.3, 1.0, 0.8 m. Their ratios are
very similar, and compared with those for orbital cycles of long and short eccentricity, obliquity and
precession (405.6, 94.9, 27.6-36.2, 15.5-22.0 ky) [Berger et al., 1994; Waltham, 2015]. Based on this
assumption the 57 inversions of geomagnetic field inversions recorded at Lopata Fm., happened during
1.2 My, suggesting an ultra-high frequency of magnetic field reversal in the Late Ediacaran, which has no
analogues in the Phanerozoic eon.
Research supported by Program of the Presidium of RAS 0135-2018-0050 and by grant 17-05-00021
from the Russian Foundation for Basic Research.
BERYLLIUM AND RELATIVE PALEOINTENSITY SIGNALS
DURING THE LAST GEOMAGNETIC REVERSAL
Tatiana Savranskaia1, Jean-Pierre Valet
1, Laure Meynadier
1, Franck Bassinot
2, Quentin
Simon3, Didier Bourlès
3, Nicolas Thouveny
3
1 - Institut de Physique du Globe de Paris, Université Paris Diderot, Sorbonne Paris-Cité, UMR
7154 CNRS, 1 rue Jussieu, 75238 Paris Cedex 05, France
2 - Laboratoire des Sciences du Climat et de l’Environnement (CEA-CNRS-UVSQ), Domaine du
CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
3 - Aix-Marseille Université, CNRS, IRD, Coll France, CEREGE UM34, Technopôle de
l’Environnement Arbois-Méditerranée, BP80, 13545 Aix en Provence, France.
Record of relative Paleointensity (RPI) and production rate of cosmogenic beryllium (10
Be) in marine
sediments are both primarily controlled by the evolution of the geomagnetic field, and therefore should
show identical variations. However, both indicators depend on complex processes within the sediment,
which can bias their relationship with field intensity. The ultimate goal of the present study is to
determine which factors can affect the records and subsequently to assess their reliability. To meet this
objective we focus on the interval surrounding the last reversal recorded in five sedimentary records from
the Indian, West Pacific and North Atlantic oceans. We took advantage of the large changes in beryllium
production (given by the 10
Be/9Be ratio, subsequently referred as Be-ratio) during this period to check for
the consistency of the Be-ratios at the five sites. We scrutinized whether similar Be-ratios were recorded
at all sites and found that neither the amplitudes nor the total amounts of Be-ratio were consistent between
sites. Various factors linked to bioturbation, lithology and digenesis can be responsible for these
100
differences. Mixing of particles by bioturbation was estimated in three cores from the distribution of
Australasian microtektite fragments that were found at the same position below the last geomagnetic
reversal. Previous studies pointed out the role of carbonates on Be adsorption by sediment particles. Here
the sensitivity of the Be-ratio to the lithology is confirmed by its linear relationship with non-carbonate
fraction, but this effect is not large enough to account for the differences in Be production between sites
during the reversal. Finally, we compared the RPI and Be-ratio variations during the period surrounding
the reversal. The most similar RPI and Be-ratios records were found in two west Pacific Ocean cores, but
with out-of-phase signals, resulting from post-depositional remagnetization. We speculate that smearing
of RPI signal removed the short-term amplitude variations, which may have improved the similarity
between the two signals.
APPLYING THE MAGNETIC FORCE MICROSCOPY TO EVALUATE THE
MAGNETIC STATES IN ROCKS
E.S. Sergienko1, S.Yu. Yanson
1, I.A. Vasilyeva
1, M.S. Lozhkin
1, A. Kosterov
1,
P.V. Kharitonskii2
1Saint-Petersburg State University
2Saint-Petersburg State Electrotechnical University “LETI”
The method of magnetic force microscopy (MFM) is widely used in both fundamental and applied
research of magnetic materials. This is one of the most promising tools for visualizing stray magnetic
fields and their distribution over the surface of a material. In particular, MFM is used in the development
of the magnetic recording materials and optimization of recording regimes of magnetic heads allowing
the super-dense information recording, and to study the structure and properties of alloys, nanoparticles,
nanocomposite materials, and thin films. MFM is also widely applied in biophysical and biomedical
research
Petrophysics is another rapidly developing field of MFM application. Potentially, it allows to observe, in
situ, the domain structure and magnetization reversal processes in magnetic minerals [cf. Haag et al.,
Geophys. Res. Lett., 20, 675 (1993); Prévot et al., Phys. Earth Planet. Inter., 126 , 75 (2001); Frandsen et
al., Phys. Earth Planet. Inter., 141, 121 (2004); Shaar and Feinberg, Geochem., Geophys., Geosyst., 14,
407 (2013]. To this end, we investigated several types of rocks and minerals with constrasting magnetic
properties, aiming to establish general patterns of mapping the distribution of magnetic fields stemming
from the cantilever interaction with the sample. Among the studied samples were quartz, flint, magnetite,
hematite, pyrite and chalcopyrite, basalts and impact melts: irghizites from the Zhamanshin astrobleme,
and tagamites from the Jänisjärvi astrobleme. We found that MFM not only allows to differentiate
ferrimagnetic minerals from non-ferrimagnetic, but also to distinguish particular magnetic states (e.g.
multidomain from single-domain), detect chemically heterophase magnetic grains, and the presence of
superparamagnetic particles. However, in the latter case, the post-processing of the MFM data (correction
for the relief, filtering, and signal transformation) is of the crucial importance.
This study was partially supported by the RFBR grant No. 18-05-00626 and used the equipment of the
resource centers of the Science Park of St. Petersburg State University: Nanophotonics, Geomodel,
Resource Center for Microscopy and Microanalysis.
101
NEW 1.86 GA PALEOINTENSITY DATA FROM THE KOLA PENINSULA
INTRUSIONS, NE FENNOSCANDIA
Shcherbakova V.V.1, Veselovskiy R.V.
2,3, Shcherbakov V.P.
1, Zhidkov G.V.
1, Smirnov
M.A.1
1GO “Borok” of Institute of Physics of the Earth, RAS, Borok, Russia
2Institute of Physics of the Earth, RAS, Moscow, Russia
3 Lomonosov Moscow State University, Moscow, Russia
[email protected]; [email protected]
The Precambrian period occupies ≈ 85% of the Earth’s geological history and accommodates all the main
formation stages of the Earth as a planet, including the emergence of its magnetic field. Variations in the
time-averaged geomagnetic dipole moment have the potential to inform us about the long-term
development of the geodynamo and its response to mantle forcing and the thermal evolution of the core.
But the determinations of intensity of the magnetic field during this period are sparse and of limited
reliability. A detailed palaeomagnetic study, the palaeointensity determinations Banc and comprehensive
investigation of magnetic properties have been performed with the Kola Peninsula poikilo-ophitic sill
rocks of the age 1860±4 Ma (according to U-Pb ID-TIMS analysis on baddeleyite grains). The electron
microscopic images of thin sections and X-ray diffractograms were performed too. Palaeomagnetic
directions calculated after stepwise thermal demagnetization of sills are Danc=352°.4, Janc=56°.8. Rocks
demonstrate thermally stable successive curves Msi(T) with clearly pronounced near-magnetite Tc.
According to the thermomagnetic criterion, high-temperature pTRMs show typical SD-PSD behavior
while low-temperature pTRMs demonstrate PSD-MD characteristics. Some correction for DS of samples
was made for Banc data obtained. Palaeointensity determinations by the Thellier-Coe (with the check-
points procedure) and Wilson methods were carried out with rocks from 6 sites. Reliable Banc values
give generally low palaeofield (less 10 µT) with corresponding VDM values in the range (1.2-2.4)x10^22
Am^2. As seen from the World paleointensity database http://wwwbrk.adm.yar.ru/palmag/index_e.html,
the Paleo- and Mesoproterozoic periods (2.5–1Ga) are marked with a noticeably low paleofield intensity
with mean VDM = 3.2x10^22 Am^2. Note that this low value led to the formulation of the Proterozoic
dipole low hypothesize (Biggin et al., 2009) and our new data support the hypothesize.
The work was funded by the grants of RFFI 16-05-00446, of RSCF 16-17-10260 and by the grant of
President of Russian Federation MD1116.2018.5.
102
PARADOXES IN THE LATITUDE DISTRIBUTION OF THE GEOMAGNETIC
FIELD VECTOR IN THE BRUNHES CHRON
Shcherbakov, V.P.1,2,3
, Khokhlov, A.V.2,4
, Sycheva, N.K.1
1Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian Academy
of Sciences
2Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences
3Kazan Federal University
4Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of
Sciences
A statistical estimation of the correspondence of empirical data on paleointensity and paleoinclination for
the Brunhes chron to the hypothesizes of the Central Axial Dipole (GAD) and the Giant Gaussian Process
(GGP) is performed. The estimation is based on a computer simulation of data corresponding to the
specified statistical characteristics of the gaussian coefficients of the spherical expansion of the
geomagnetic field. The estimates performed have shown that according to the Kolmogorov-Smirnov and
Anderson-Darling tests, the GAD hypothesis in its canonical form should be rejected. The extension of
GAD to GGP with nonzero time-averaged quadrupole and octupole terms restores the agreement between
the empirical data on paleointensity and GGP model. The same is true for the paleoinclination data, but
the problem is that these two models are mutually exclusive since their parameters do not agree with each
other. Namely, testing of paleoinclination data by the GGP model showed the need for the introduction
only relatively small corrections to the purely dipole geomagnetic field. At the same time, the requirement
of statistical correspondence of the paleointensity data to the GGP model revealed a necessity to include
to introduce a high quadrupole contribution (1/3 of the dipole coefficient value). The most likely cause of
such the contradiction may be artifacts associated with erroneous of paleointensity determinations, but
even with this interpretation, the question of reasons for the existence of such the strong latitudinal
dependence of the virtual axial dipole (VADM) intensity fixed by the empirical data remains unresolved.
The work was supported by the state assignment 0144-2014-00117 and the Ministry of Education
(contract No. 14.Z50.31.0017).
CHECKING THE DIMENSIONS OF COULOMB'S LAW FOR STATIONARY
MAGNETIC FIELD AND THE DETERMINATION OF THE DISTANCES TO
THE ELEMENTARY SOURCES IN MAGNETOMETRY
Sorokin A.G.
Federal State Budgetary Institution VIMS
Presented are the major complicating factors at measurements of force of magnetic interaction in Ch.
Coulomb's experiments in 1785 - 1789. The most significant of them is marked by the effect of the
displacement of the position of the magnetic masses due to the influence of the opposite ends of the
magnets. The verification of dimensions included in the formula of the Coulomb's magnetostatic law, in
103
which the force of interaction depends inversely on the distance to the sources in the second degree,
revealed inaccuracies.
Based on the results obtained, it is stated that the force of interaction of magnetic poles is inversely
proportional to the distance in the fourth degree. An expression is given for the absolute value of the
strength of the total magnetic field vector, in which the field is inversely proportional to the distance in
the third degree.
Carried out the check of solutions of the inverse problem for simple magnetically disturbing bodies
(horizontal and vertical material line, point source) in software packages by different methods of singular
points, the most accurate of which confirm the submitted statements about the degrees of distances with
high accuracy.
ANALYTIC SCALING LAWS IN PLANETARY DYNAMO MODELS
Starchenko S.V.
IZMIRAN, Kaluzhskoe hwy 4, Troitsk, Moscow, 108840 Russia
Numerical models of planetary MHD dynamos have led to many advances in the last twenty years. However,
the accessible parameter space of these models is somewhat limited due to computational constraints. A
number of numerically based scaling laws have been proposed, but it has been difficult to reliably confirm
them from the simulation data alone. Since these scaling laws have to be used to extend the numerical models
into the planetary parameter regime, getting correct scalings is an important issue. Here possible balances
between the relevant terms in the dynamo equations are considered, and a number of different known and new
analytic scaling laws are proposed. Some of these laws are compatible with the famous Christensen-Aubert
(2006) scaling for the magnetic field strength. Plausible estimates of the typical values of the important
quantities in the Earth’s core and other Terrestrial planets are made, and the extent to which the various scaling
laws are consistent with these estimates is discussed.
The current millennium started with cheerful blossom of numerical Earth’s/planetary MHD dynamo-like first
principal models that were originated by the pioneering work of Glatzmaier and Roberts (1995). Despite
tremendous remoteness of the key models’ parameters from the real dynamos, those models were able to
reproduce some observable geodynamo / planetary / stars’ features and even to access to the real objects via
the scaling laws. Those laws were first based on inviscid limit. In contrast, King and Buffett (2013)
demonstrated prevailing viscous control for all the explored models. This paper supplements their numerical
estimations by analytic magnetic/energy estimations and formulates the conditions for such viscous regime to
exist, while the major goal of this paper is to find the true diffusion-free scaling for the convective MHD
dynamos in the Terrestrial planets. Unfortunately, as Cheng and Aurnou (2016) showed it, the available
numerical models are principally not able to produce such diffusion-free scaling laws. Thus, because of the
limited range of parameter space in which dynamos can be found, several different proposed scaling laws give
reasonable fits to the numerical simulation data. The problem is that the numerical models cannot discriminate
between a numbers of plausible, but different, scaling laws, while analytic models could hopefully be able to
do this at least to some extent. I am trying to do it in the frame of somewhat standard one initially unknown
dimension scale (one-scale) scaling (Starchenko and Jones 2002, Christensen 2010) and my (Starchenko 2014)
two-scale scaling that is sufficiently improved.
The section 2 of this paper is devoted to the known and my new integral conditions those are useful for the
further formulations of the searching scaling laws via the simplest possible balances. In the section 3, I explore
viscosity dependent and independent planetary dynamo scaling in the frame of classical one-scale scaling. The
major section 4 is devoted to my modified two-scale scaling that results in two sets of scaling laws with
moderate and strong domination of magnetic energy over kinetic one. In the final section 5, I draw conclusions
and discuss applicability limits of my and others scaling laws.
References
104
Cheng, J.S., Aurnou, J.M., 2016. Tests of diffusion-free scaling behaviors in numerical dynamo datasets. Earth
and Planetary Science Letters, 436, 121–129.
Christensen, U.R., Aubert, J., 2006. Scaling properties of convection-driven dynamos in rotating spherical
shells and application to planetary magnetic fields. Geophys. J. Int., 166, 97–114.
Christensen, U.R., 2010. Dynamo Scaling Laws and Applications to the Planets. Space Sci Rev., 152, 565-590.
Glatzmaier, G.A., Roberts P.H., 1995. A three-dimensional convective dynamo solution with rotating and
finitely conducting inner core and mantle. Phys. Earth Planet. Int., 91(1–3), 63–75.
King, E.M., Buffett, B.A., 2013. Flow speeds and length scales in geodynamo models: The role of viscosity.
Earth Planet. Sci. Lett., 371, 156–162.
Starchenko, S.V., 2014. Analytic base of geodynamo-like scaling laws in the planets, geomagnetic
periodicities and inversions. Geomagnetism and Aeronomy, 54(6), 694-701.
Starchenko, S.V., Jones, C.A., 2002. Typical velocities and magnetic field strengths in planetary interiors.
Icarus, 157, 426–435.
VARIATIONS OF ENERGY AND POWER FOR A POTENTIAL
GEOMAGNETIC FIELD SINCE 1840
S.V. Starchenko and S.V. Yakovleva
Pushkov Institute of terrestrial magnetism, ionosphere and radio wave propagation, Kaluzhskoe Hwy
4, Troitsk, Moscow, 108840 Russia
[email protected]; [email protected]
Probably for the first time, independent on spherical radius spatial-spectral components of energy and
power of the potential part of the main geomagnetic field were determined and investigated. The energy is
obtained by integrating its known radial density from the Earth’s core to infinity, and power is a time
derivative of energy.
Based on three well-known observational models of the geomagnetic field, the total and spectral
variations of energy and power have been analyzed from 1840 to 2020. The total energy (~ 6∙1018
J) and
power (~ 108 W) are determined by the sum of odd harmonics: dipole n = 1, octupole n = 3, etc. The
dipole dominates and its energy is close to the entire energy of the field symmetric with respect to the
rotation axis. The energy variations are ~ 10% and are similar for all models except for the "splash" of the
IGRF model in 1945-1950. A comparative spectral analysis showed that the "splash" is concentrated in n
= 9 and 10, and the variations of the other harmonics are similar in all models. In this case, n = 3
dominates over n = 2. The decrease is fixed for n = 3 to n = 8, and then the dominance of n = 9 over n = 8
and n = 10. The average powers close to zero at n > 1 indicate an almost periodic behavior of the non-
dipole field, and the significant power variations indicate a strong non-linearity of the geodynamo. The
results of the work are consistent with modern geodynamo-like models.
Such a significant IGRF "splash", which can have a nonlinear geodynamo nature, is a real challenge.
Alternatively, this may be some artificial shortcoming of the IGRF model. One more reason is the fact
that two other "quiet" models were exposed to excessive smoothing. In any case, this feature, discovered
by us, earns the close attention of the world's geomagnetic and dynamo community.
105
RECONSTRUCTION OF JURASSIC SEDIMENTARY ENVIRONMENTS
USING ROCK-MAGNETIC DATA IN THE MIKHAYLOVTSEMENT
REFERENCE SECTION (RYAZAN REGION, RUSSIA)
Stepanov I.A.1, Kazansky A.Yu.
1,2, Kosareva L.R.
3, Rogov M.A.
2, Tesakova E.M.
1,2,
Shchepetova E.V.2
1- Geological Department of Lomonosov Moscow State University, Moscow, Russia
2- Geological Institute of Russian Academy of Sciences, Moscow, Russia
3- Kazan (Volga Region) Federal University, Kazan, Russia
The Mikhaylovtsement reference section (54°12'43.0"N 38°56'13.0"E) is located in the quarry where
about 20 m of Jurassic mudstones, clays, silstones and sands are exposed. Abundant ammonites and
microfossils occurred throughout the section enable to identify the age of the succession as Early
Callovian–Early Oxfordian. The purpose of the study is to reconstruct sedimentary environments and
their evolution during this time interval on the base of rock magnetic data, and to compare them with
lithofacies, micropalaeontological and paleoecological data. We used magnetic hysteresis with
decomposition of coercive spectra as a main magnetic method. Thermomagnetic analysis Js(T) was used
for determination of magnetic minerals.
The main result of the study is rock-magnetic model that is proposed for reconstruction of sedimentation
history of Mikhaylovtsement succession during the Early Callovian – Early Oxfordian. The model
includes 7 rock-magnetic zones corresponding to different sedimentary environments and gives the base
for the following conclusions:
1) The origin of ferromagnetic fraction in the studied sediments is mostly biogenic. It is represented by
single-domain greigite originated from magnetotactic bacteria.
2) Regularities in alternation of rock-magnetic zones over the section allow to determine the boundaries
of transgression-regression (T/R) events. Three T/P events corresponding to rock-magnetic zones 3-5 are
fully confirmed by ostracod analysis. Additionally 2 independent T/P events are recognized in rock
magnetic zones 6 and 7 only by ostracod data.
3) On the base of appearance of coarse-grained magnetite and increase of paramagnetic content (not
associated with Fe-sulfides and carbonates) the intervals of intensive terrigenous input were recognized.
4) The primary variations in the organic matter content have been recognized due to irregular increasing
of pyrite concentration in the sediments.
Those conclusions not only coincides with the modern viewpoints on the evolution of the sedimentary
environment in the Mikhaylovtsement reference section but also provide the additional information
especially in determination of magnetic minerals, their sizes and genesis.
This study has been supported by the RFBR, project no. 18-05-00501 (TEM) has been carried out
following the plans of the scientific research of the Geological Institute of RAS, project no 0135-2018-
0051 (SEV) and according to the Russian Government Program of Competitive Growth of Kazan Federal
University (LRK).
106
СOMPUTER MODELING OF THELLIER AND WILSON METHODS ON SD
GRAINS CARRYING TRM AND CRM
Sycheva, N.K.1, Shcherbakov, V.P.
1,2
1 Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian
Academy of Sciences
2 Kazan Federal University
The Haig’s mechanism of CRM acquisition when CRM is acquired as a result of growth of ferrimagnetic
grains in an external field B at a constant temperature TCRM is considered. The computer simulation was
performed by the Monte Carlo method taking into account the magnetostatic interactions between the
grains. The initial particle size was set in the interval 33-37 nm (TCRM = 400° C) and 44-47 nm (TCRM =
500 ° C) so that on laboratory time scales these particles were superparamagnetic. The final sizes of the
blocked particles ranged from 40 to 90 nm. The resulting CRM + pTRM was "thermally demagnetized"
when the ensemble was "heated" to TC = 585° C. The formation and "thermodemagnetization" of TRM
were carried out with a similar scheme. Each Arai-Nagata diagram display extended close to straight line
segment by which it is possible to determine the "paleointensity" but its value always turns out to be 2-3
times lower than the true field used in the course of modeling. The same underestimation was also
observed for the Wilson’s diagrams. Similar results were obtained for noninteracting grains so the
presence of interaction cannot be the cause of the similarity of the blocking temperature spectra. The
work was supported by the state assignment 0144-2014-00117 and the RFBR grant 17-05-00259.
STRUCTURAL TRANSFORMATIONS OF TITANOMAGNETITE IN
NATURAL BASALTS OF THE RED SEA DURING OXIDATION
Tselebrovskiy A. N., Maksimochkin V. I., Grachev R. A.
Lomonosov Moscow State University, the Faculty of Physics
Paleomagnetic studies are based on an analysis of the primary, or thermo-resistant, magnetization of
rocks. The problem of separating the thermic and chemical components of magnetization has not been
solved yet. An erroneous interpretation of the nature of magnetization can significantly affect the results
of determining the paleointensity.
In this work, samples of basalts from the rift zone of the Red Sea, with an average content of ulvospinel
of 52 % and a Curie temperature of 260 °C, were annealed during 4.5–110 hours, at a temperature of
350 °C. Then SEM, TEM and XRD studies were conducted on the obtained states to determine the
structure and changes in the elemental composition in grains of titanomagnetite.
It has been established that with an increase in the annealing time up to 110 hours, the lattice parameter
decreases from 8.455 Å to 8.417 Å. At the same time, the Curie temperature rises from 260 °C to 490 °C.
This behavior is typical for single-phase oxidation. Deviations from the cubic structure were found in the
sample with the maximum annealing time. The sample with the longest annealing time was then held in
an atmosphere of pure argon (99.99%) for 40 minutes at 610 °C. After this exposure, TEM showed an
increase in the lattice parameter to the initial value and a return to the cubic structure. At the same time
the Curie temperature fell from 490 °C to 265 °C. On the investigated grains of titanomagnetite less than
107
10 micrometers in size, TEM and STEM showed no structural or elemental inhomogeneities, which also
indicates a single-phase oxidation process.
The results of the work show that annealing basalts in air at a temperature of 350 °C leads to a single-
phase oxidation of titanomagnetite. Subsequent heating to 610 °C in argon atmosphere promotes its
reduction.
This work was supported by the RFBR (project 16-05-00144).
MORPHOLOGY AND COMPOSITION OF FOSSIL COSMIC DUST FROM
VARIOUS SOURCES
Tselmovich V.A.1, Kuzina D.M.
2, Nourgaliev D.K.
2, Garin E.V.
3. Philippov D.A.
3
1Borok Geophysical Observatory IPE RAS, Borok, bldg. 142, Borok 152742, Nekouz district,
Yaroslavl reg., RF
2Kazan Federal University, ul. Kremlevskaya 18, Kazan, 420008, RF
3Institute for Biology of Inland Waters named after I.D. Papanin RAS, 109, Borok, Nekouz District,
Yaroslavl Reg., 152742, RF
Using a microprobe, the morphology and composition of the magnetic component of cosmic dust (CD) of
various origins were studied. CD constantly arrives on the Earth and accumulates in various environments
(peats, sedimentary rocks, etc). Extraction of CD were made by using neodymium magnet. However, with
the particles of our interest were extracted particles of volcanic and anthropogenic origin. They differ in
size, morphology and composition. The correct identification of particles depends on the capabilities of
the microprobe and the art of the operator and has a stochastic nature. It is important to have a set of
criteria to reliably identify the CD. Such criteria have been developed. To identify the features and
differences of CD from various locations, a spatial slice consisting of 4 sampling points and a time slice
were considered. The time slice presented by different age-dated specimen from the sediments of the lake
Pleshcheyevo with age from 556 to 6071 BC.
The spatial section was represented by peat from flat marshes from the Myshkin and Nekouzsky districts
of the Yaroslavl Region, peat from the Tunguska space body (background peat horizons) fall site, from a
peat borehole in the Kabardino-Balkarian Republic (sphagnum marsh, 1764 m ASL).
It was shown that the common features of CD are: 1) Mt balls with a detrital structure formed during
meteorites entering to the Earth’s atmosphere; 2) Mt micrometeorites with a well-crystallized surface; 3)
particles of pure native Fe with a size from 1 μm to 500 μm; 4) native metals (Zn, Ni, Cu, W, etc.); alloys
and intermetallides (FeNi, FeCr, FeAl, FeW, CuZn, etc.). In this case, particles larger than 50 μm had
signs of melting as a result of heating in the Earth's atmosphere during a fall. Particles smaller than 50 μm
reach the Earth's surface without heating. It is noted that the ratio of the amount of CD and terrigenous
substance in flat peat is higher than in peat selected in the mountains.
The peculiarities of the composition of CD can be attributed to a different ratio of the amount of pure Fe
and intermetallides, as well as a set of intermetallic compounds, specific for each analyzed point of
selection. In some samples, the presence of nanodiamonds and carbonaceous microspheres was noted.
The study showed spatial and temporal homogeneity in the composition of the CD flux arriving on Earth
in the Holocene. The catastrophic layers were not considered.
Supported by AAAA-A17-117040610183-6 and RFBR, 16-05-00703a.
108
THE POSSIBILITY OF DETERMINING THE AGE OF THE NORASHEN
SECTION OF LAKE SEVAN
A.A. Vardanyan, R.Y. Stakhovskaya
Institute of Physics of the Earth, Russian Academy of Science, Moscow
Complex magnetostratigraphic and magnetochronological studies of the Holocene sediments of the Sevan
basin were carried out at the mouth of the Argichi river near the South- Western shore of Sevan lake. The
most interesting section is located 3.5 km from the village of Lchashen (near the village Norashen) in the
recess of the highway, in the study of which was found buried under lake sediments ancient Norashen
settlement.
Lake sediments here are leaned against young andesite-basalts under the canopy. The apparent thickness
is 4.5 km. The structure of deposits indicates a two-fold rise in the level of Lake Sevan. The first, the
most ancient transgression, is recorded in the sediments of the interval 3.0 – 4.5 m. It was separated by
very short-term regression or temporary retreat of lake waters, expressed by swamp soil of 3.60- 3.70 m
interval. The time of completion of this transgression was determined by the shells of mollusks from a
depth of 3m. Limnaea stagnalis (L.), L. (Radix) ovata (Drap.), planorbis (L.), Gyraulus laevis (Alder),
pisidium casertanum (Poli), Succinea obionga (Drap) have been studied by the radiocarbon method,
which showed the figure of 6270 ± 110 (MGU -215) at a depth of 3 m.
The second transgression is reflected in precipitation of the range 0.50 -1.50. Clam shells from a depth of
approximately 1 m: Limnaea stagnalis (L), L. (Radix suricularia (L.)), Valvata Piscinalis (Mull) Planorbis
planorbis (L.), Pisidium casertanum (Poli), Succinea putris (L). Their age by C14
at a depth of about 1 m
is 2090 ± 70 (MGU -244).
Thus, for more than 4,000 years between these two transgressions, the waters of Lake Sevan stood at a
lower level. The cultural horizon of the interval 1.50 -2.95 m shows that during this time on this stretch of
coast twice settled people - in the III Millennium and in the middle of the II Millennium. The break in the
settlement lasted at least 500 years. Available data suggest that over the past 5,000 years people have
lived on the shore of lake Sevan.
Early bronze, that is, the culture of the III Millennium BC, in the Norashen section is expressed in three
layers, the thickness of which is about 1.45 m. The lower building layer has a dark gray color, sometimes
black, contains layers of ash. In the upper part of the lake sediments at a depth of 2.95 m mounted floor of
pebbles of volcanic origin, which is smeared with clay on top. The layer contains a large number of bones
of small and large cattle, bones of a dog and a horse, reptiles, amphibians, fish, bones of birds, usual stone
and bone tools, playing circles and a large number of black-absorbed ceramics. There are shells of
freshwater and terrestrial mollusks. Above the lower layer is the middle layer of brown color with
thickness of 25-30 cm, the floor is also mounted with small pebbles and top smeared with clay, rich in
ceramics and animal bones.
The floor of the top layer consists of two layers: the lower layer has a dark olive greenish color, and the
upper - light. Shards of black-flattened ceramics and animal bones were found in the layer. Traces of fires
were also found. The thickness of layer is 30 cm.
The late bronze age is characterized here by a layer of light brown with a grayish tinge in the thickness of
20-25 cm, which is located above the upper construction layer of the III Millennium with a break in
sedimentation is about 500 years old (due to a decrease in the level of lake Sevan). A small amount of
ceramic debris found in the layer enables this layer to be pre-dated to the middle of the II Millennium.
Thus, archaeological and radiocarbon data make it possible to accurately determine the age of the
Norashen section, which gives the right to consider it quite favorable for the study of the paleovecal
variations on the Holocene sediments.
109
ESTIMATION OF SUITABILITY OF SEDIMENTS OF THE SECTION OF
DZKNAGNET RIVER FOR STUDYING THE FINE STRUCTURE OF
GEOMAGNETIC FIELD
A.A. Vardanyan, R.Y. Stakhovskaya
Institute of Physics of the Earth, Russian Academy of Science, Moscow
Sedimentary rocks both marine and lake are very suitable for paleomagnetic inquiries because
sedimentation in water bodies is the most uniform and continuous process, the least susceptible to
disturbances of all known in geology processes. With this purpose we chose the Dzknagnet section,
sediments of which, as previous studies showed, are very suitable for paleomagnetic inquiries.
The Dzknagnet section is located on the left bank of the Dzknagnet River, in the site where the river
drains into Sevan Lake. Samples for dating were taken at a depth of about 2 m from the sand layer with
great amounts of well-conserved mollusk shell and wood. The С14
dating yields for this depth the age of
940 ± 220 (on shells) and 1010 ± 250 years (on wood). The behavior of the magnetic parameters suggest
that ferromagnetic fraction in sediments is not modified, which is evidenced by similarity in the curves
Irs(T), Is(T). The sharp distinction of the average values of J and D in the lower section is believed to be
related to the tectonic history of the region.
The Zijderveld curves taken from two-thirds of the collection samples showed the presence of three
components that appeared at the corresponding temperatures of (1) - 250С, (2) -350
С and (3)-500
С.
The components are likely to be associated with (1) – titanomagnetite, (2) – titanomaghemite and (3) –
magnetite. The component analysis is made difficult by the fact that at temperatures on the order of 200С
not only the magnetization of the first component Tc, but also the viscous magnetization will be removed.
Judging from a great scatter of results in determining this component, an essential fraction of the viscous
magnetization is not natural, but of laboratory origin. Clearly this component cannot be used for studying
secular variations.
Variations by archaeomagnetic data are resolved with an accuracy of ±10%.As it easy to see geomagnetic
variations revealed in the Dzknagnet section and those from archaeomagnetic data differ from each other
within the errors of their determinations.
Comparison of the results obtained from our study of sediments in the Dzknagnet section to
archaeomagnetic data for the same time interval and in the same region showed that the paleomagnetic
record gives correct representation of geomagnetic field variations. This permits us to assess with the
credence the data of secular variations from paleomagnetic studies that due to continuity of data series
offer a certain advantage over the archaeomagnetic method.
At the sedimentation rate of 26 years/level the found variations have the periods 169±26, 230±26,
380±26, 660±26, 910±26 years.
The 180, 360, 600 and 900 year periods are known from both direct and archaeomagnetic observations,
the 230-year variation exhibiting only in the scalar parameters may be related to climatic changes and no
suppositions exist to the 280-year variations.
110
FOUR INDEPENDENT ISOTOPIC GEOCHROMETERS IN
PALEOPROTEROZOIC DOLERITES FROM THE KOLA PENINSULA AS
THE BASIS FOR THE NEW ~1.86 GA FENNOSCANDIAN KEY
PALEOMAGNETIC POLE
Veselovskiy R.V.1,2,3
, Samsonov A.V.3, Stepanova A.V.
4, Sal’nikova E.B.
5, Larionova
Yu.O.3, Travin A.V.
6, Arzamastsev A.A.
5, Egorova S.V.
4, Erofeeva K.G.
3, Stifeeva
M.V.5, Esenkov A.A.
1, Chistyakova A.V.
1
1 – Geological department, Lomonosov Moscow State University, Moscow, Russia
2 – Schmidt Institute of Physics of the Earth RAS, Moscow, Russia
3 – Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry RAS, Moscow,
Russia
4 – Institute of Geology, Karelian Research Centre RAS, Petrozavodsk, Russia
5 – Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences, Saint
Petersburg, Russia
6 – Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Sciences,
Novosibirsk, Russia
We present the results of detailed paleomagnetic studies of Proterozoic dolerite sills exposed within the
Murmansk block of the Fennoscandian Shield for more than 200 km of the coastline of the Barents Sea.
The paleomagnetic pole, which we consider as the new key pole for Fennoscandia, is calculated from the
mean direction of the ChRM in 15 sites, representing at least 8 independent intrusive bodies. The backed
contact test was undefined in all cases due to weak magnetization of the host rocks, mostly granites and
gneisses. Because the ChRM has only one polarity, we couldn't use the reversal test. Thus, in order to
determine the time of the ChRM’s acquisition, we used four independent methods of the isotope dating.
Complex studies of U-Pb, Sm-Nd, Rb-Sr and Ar/Ar (biotite) methods were carried out for a thick (about
30 m) sill. The U-Pb method on baddeleyite gave a concordant age of about 1.86 Ga; estimates of the
isotope age, obtained by other methods, are consistent with this date. The obtained data indicate pretty the
same time of the closuring of four radiogenic isotope systems in different magmatic minerals of the
Paleoproterozoic (1860 million years) dolerite sills on the Murmansk craton. The present study is a rare
example, when the timing of magnetization is surely proved in the absence of the possibility of applying
field tests or if their result is not determined.
This work was funded by the grants #16-17-10260 (RSF), #14.Z50.31.0017 The Russian Government),
MD1116.2018.5.
111
ROCK MAGNETISM AND PALEOMAGNETISM OF THE EDIACARAN
SEDIMENTS OF THE YENISEI RIDGE VOROGOVKA SERIES
E.V. Vinogradov, D.V. Metelkin, V.V. Abashev
Novosibirsk State University, Novosibirsk
Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk
The dynamics and time of the separation of Siberia from the structures of Rodinia remains one of the
most controversial issues in the reconstruction of the geological history of the Siberian Platform.
Paleomagnetic data are very important in resolving existing contradictions under the condition of a well-
founded and detailed paleomagnetic study of the Neoproterozoic geological complexes of Siberia. Such
complexes are located on the framing of the Siberian craton, forming, in the main, sedimentary
sequences.
The paper gives new paleomagnetic data from the Vorogovka Series on the Western margin of the
Siberian Platform. The Vorogovka Series is a complex of carbonate-terrigenous sedimentary rocks,
preserved in small graben-synclinal structures in the northwest of the Yenisei Ridge. The recent data
indicate that the age of sedimentation within the Vorogovka Basin is less than 585 Ma. Bottom-up in the
stratigraphic sequence, the Vorogovka Series is divided into the Severnaya Rechka, the Mutnina and the
Sukhaya Rechka Formations.
There are at least 3 regular components of the magnetization in the rocks of the Vorogovka Series. The
stable part, probably of an orientational origin, is found only in the rocks of the Sukhaya Rechka
Formations, is primary and corresponds to the magnetic field that existed during sedimentation. The
remaining regular components are metachronous and reflect the different stages of the Paleozoic
geological history of the northwest of the Yenisei Ridge.
Using the Halls method, the directions of high-coercive component for Sukhaya Rechka Formation were
established. The paleomagnetic pole is located at Plat=-29.3°; Plon=41°; with 95% confidence radius
B95=2.1°. The site-means of high-coercive component have the best clustering in stratigraphic
coordinates. The maximum K-statistics (Kmax=699) is achieved at 109.8% of unfolding, thus, the fold
test shows that the acquired magnetization is pre-folded. In accordance with this definition, the
paleogeographic position of the Vorogovka Basin at the time of formation of the studied rocks should
correspond to the equatorial latitudes of the southern hemisphere (PL =-8.1°).
The work was supported by the Ministry of Education and Science of the RF (project No.
5.2324.2017/4.6) and the RFBR (project No. 15-05-01428).
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DATE OF TRM OF GRANITE BATHOLITH: IS IT POSSIBLE?
Vodovozov V.Yu.1,2
, Zakharov V.S.1, Zverev A.R.
1,2, Travin A.V.
3
1 – Lomonosov Moscow State University, Faculty of Geology
2 – Geological Institute RAS
3 – Institute of Geology and Mineralogy SB RAS
The time gap between crystallization and the formation of TRM in large intrusions can reach great values.
Probably the only way to directly determine the age of TRM is to date using isotope data on various
minerals (the thermochronology method). Mathematical modeling of the cooling rate makes it possible to
simplify the research. In a similar way was in the study of the Early Proterozoic granites of the Kodar
complex in the south of the Siberian craton. Granite batholiths lie in the Olekma block of the Aldan
Shield. We studied for paleomagnetic analysis 769 samples from 5 massifs – At-Bastakh, Hani, Kemen,
Ikabi and Kodar. Everywhere there were rocks suitable for obtaining a paleomagnetic poles. Primary
nature of the high-temperature components of the NRM is confirmed by positive reversal test and
coincidence of directions in the remote intrusions. Paleomagnetic pole Plat = -21.9 Plong = 101.8 A95
= 8.2 is obtained by averaging the poles of 5 massifs.
Biotites and feldspats were sampled from the granites of At-Bastakh for 40
Ar/39
Ar investigations. A total
of 12 spectra were obtained: the apparent ages of biotites lie within a narrow interval, 1837-1859 Ma, and
the age of the feldspats were strongly rejuvenated. Taking into account the U/Pb zircon age of 1873+/-3
Ma (Larin et al, 2000), we obtained an interval of about 20 Ma between crystallization of the rock and
cooling down to 300 degrees. Such a value is difficult to obtain with the help of mathematical modeling.
Preliminary mathematical modeling showed that at "instantaneous" intrusion the time gap between the
closing temperatures of the isotope systems of zircon and biotite does not exceed 1 million years. The
most likely explanation for the discrepancy is the time-stretched intrusion, because all massifs have a
two- or three-phase structure.
The study was supported by the RFBR, grant No. 17-05-01132.
CORRECTION FOR A WEAK RESIDUAL MAGNETIC FIELD IN THE
FURNACE DURING THE PALEOINTENSITY DETERMINATION BY
THELLIER-COE METHOD
Zhidkov G.V.
Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian Academy
of Sciences
It is assumed that during a paleointensity determination by Thellier-Coe method one of the double
heating-cooling cycles in a furnace shall occur in absence of a magnetic field, i.e. at zero field. However,
in practice there exists residual magnetic field vector F0 = F0x, F0y, F0z. In the thermomagnetometers
and the electric furnaces of the Borok geophysical observatory this field is estimated at 1 μT. This is
reflected in the Arai diagram in that the NRM value doesn’t disappear to zero with temperature T
increasing. At the same time the NRM components pass by the origin in the Zijderveld diagram and go
toward the F0. Consequently, it produces an error in the Thellier-Coe paleointensity determinations of the
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order intensity of F0. Here it is proposed a correction algorithm to remove this error based on the
following equations.
(1) After first heating to temperature T1 the magnetization vector M1of the sample:
M1 = NRM(Tc,T1)+pTRM(T1,T0,F0)
(2) Accordingly, after second heating to T1 the magnetization vector M2of the sample:
M2 = NRM(Tc,T1)+pTRM(T1,T0,F0)+ pTRM(T1,T0,FL), where FL is the laboratory field.
(3) pTRM(T1,T0,FL) = M2(T1) – M1(T1)
(4) If F0 components (F0x, F0y, F0z) are known then the components of pTRM(T1,T0,F0) are:
pTRM (T1,T0, F0x) = F0x * pTRM (T1,T0,FL) / FL
pTRM (T1,T0, F0y) = F0y * pTRM (T1,T0,FL) / FL
pTRM (T1,T0, F0z) = F0z * pTRM (T1,T0,FL) / FL
(5) From (1) and (4): NRM(Tc,T1) = M1(T1) – pTRM(T1,T0,F0)
The algorithm was successfully applied during the paleointensity determinations in GO Borok. This work
was supported by RFBR grant 16-05-00446.
PALEOMAGNETISM OF THE EARLY PROTEROZOIC BASITE
COMPLEXES OF THE OLEKMA BLOCK OF THE SOUTH OF THE
SIBERIAN CRATON
Zverev A.R.1,2
, Vodovozov V.Yu.1,2
1 – Lomonosov Moscow State University, Faculty of Geology
2 – Geological Institute RAS
This paper presents the results of the paleomagnetism study of the Tsina gabbroids (U/Pb age for zircons
1867+/-3 Ma), Kuranakh (U/Pb age for zircons 1863+/-9 Ma) and Doross (U/Pb age for baddeleyite 1752
Ma) complexes. The work purpose is to obtain paleomagnetic poles for studying the structure formation
of the Siberian craton’s south at the Early Proterozoic end.
Samples of Tsina complex’s gabbroids were selected in the petrotype - Tsina massif and 7 intrusive
bodies. The pole of the Tsina complex is calculated by averaging the two paleomagnetic poles - the Tsina
massif and other intrusive bodies: Plat = -18.3o Plong = 93.1
o A95 = 10.5
o. Diabases of the Kuranakh
complex were selected in 4 intrusive bodies. High-temperature NRM components, antipodal to the
components of the Tsina complex, are distinguished here. It was possible to obtain a positive contact test
for the Kuranakh complex. Paleomagnetic pole of the Kuranakh complex: Plat = -22.7o Plong = 102.3
o
dp/dm = 5.6/10.9. Gabbroids of the Doross complex are selected from 8 intrusive bodies. Many samples
have a large NRM value. The average directions of the sites are placed on the stereogram practically
chaotically, there is only one cluster of 3 sites. The pole calculated by this direction: Plat = -30o Plong =
79.3o dp/dm = 2.5/4.9.
The poles of the Tsina and Kuranakh gabbroids practically coincide with the same-aged poles of the
Olekminsky block and the Baikal ridge, which indicates the consolidation of the craton south by 1870
Ma. The pole of the Doross gabbroids differs from the one-age poles of the Baikal ridge, further research
is required to explain this difference.
The study was supported by the RFBR, grant No. 17-05-01132.
114
115
SECTION S. SEISMOLOGY
Conveners - Prof. T.B. Yanovskaya, Prof. V.N. Troyan
Seismology and phenomena in the Earth's interior and in the near-Earth space
related to earthquakes including:
Theory of seismic wave propagation
Earth's structure from seismic data
Global and regional seismicity and earthquakes sources
Phenomena related to earhquakes: Electromagnetic anomalies, Seismic
noise, Earthquake precusors, Slow tectonic movements
Methods for seismic data processing
Methods of seismic prospecting
TECTONIC PLATES MICROMOTIONS CAUSED BY THE CHANDLER
WOBBLE
Blagoveshchenskaya Elena
SPbF Izmiran, St.Petersburg, Russia
The problem of the correlation of the global dynamic phenomenon "Chandler wobble" with the local
dynamics in different parts of the Earth's crust and lithosphere is wide of the solution. In this paper the
trail to examine this problem using variation in the monotonous secular process of seismotectonic
deformation in the restricted geospace volumes (GSV) around the uniform seismoactive regions is made.
Some ideas, concepts of the plate tectonics model and its global map are used.
The Euler or Chandler wobble is free rotation mode of the Earth. Its driver is the deep mantle- the most
hard and most massive Earth's layer, whose large inertia tensor value is able to keep up Chandler's
specific rotation of the Earth for a long time. In the geocentric coordinate system where daily rotation is
absent, Chandler wobble occurs to be the main (very slow) rotation of the Earth (as the whole) around the
current equatorial axis. We denote this angular rotation velocity vector as E14(t), using "14" as a symbol
of the Chandler's phenomenon. The pole of E14(t), EP14(t) moves along the equator eastward(s)
passing its 360o in about 14 months (430 days). Chandler wobble influence on the array of numerous
seismic events in the GSV (during long time, 1965-1990) we determine by the function EP14gsv which
indicates the most typical position EP14(t) the when the earthquakes used to occur.
We investigated numerous GSVs and discovered that for many of them it is possible to determine
EP14gsv. Large GSVs around mid-ocean ridges in the southern latitudes (2 - 55)S in the Atlantic Ocean,
in the Western Indian Ocean and in the Pacific Ocean have reliable EP14gsv parameters, and they prove
to be different. This fact indicates that Chandlers wobble influence indeed has some space factor.
EP14gsv examples around the West African tectonic plate (with deep Archean roots) indicate, that this
equatorial plate is drawing into Chandler's rotation most effective if the EP14(t) is not far from the plate's
116
center of inertia. For these examples and examples for GSVs in Tibet, Himalaya or Zagros as regions of
collision and for other GSVs some comparisons with the classic tectonic plate motions were made.
Seismic data (1965-1990, M=2-6) were taken from USGS catalog (http://earthquake.usgs.gov).
Astronomic data were taken from (Kotlyar and Kim, 1994).
SHORT-TERM PRECURSORS OF EARTHQUAKES
Dovbnya B.V.
Borok Geophysical Observatory of IPhE RAS, Yaroslavl Region, Russia
According to magnetic measurements at two mid-latitude observatories, the Borok Geophysical
Observatory (58.1 ° N, 38.2 ° E) and the Geophysical Observatory College (64.9 ° N, 212.0 ° E), low-
frequency (0 to 5 Hz) electromagnetic signals tied to earthquakes in time and not correlated with other
geophysical phenomena were detected. The timing of the signal relative the time of the earthquake ranged
from tens of seconds to the first units of minutes with a statistical significance p = 0.87. Signals from
remote earthquakes were observed in Borok and College in the form of either single or paired impulses
(less often as a series of pulses). In 70% of the total number (about 400) they were observed before the
earthquake. The lead time was 1 to 5 minutes. Precursors were recorded before the devastating
earthquakes in Japan, China, Romania, before earthquakes in Turkey and other seismically active regions.
A remarkable property of the precursor repeatability was found in the character of the described
seismoelectromagnetic activity. If the main earthquake was preceded by an ULF electromagnetic pulse,
then repeated seismic events in the same region (aftershocks), also can be preceded by anticipatory
signals. In this case, the type of emission (single or paired pulses) remains unchanged for the entire series
of aftershocks.
The physics of precursors is far from obvious. It is clear that each of these signals is one of the
manifestations of processes that occur before earthquakes, and in one way or another, are connected with
it. Usually, induction and piezomagnetic mechanisms are considered as a possible cause of generation of
seismoelectromagnetic signals. The riddle is the appearance of two or more consecutive pulses, as a
manifestation, apparently, of similar processes in the terrestrial interior. Perhaps the explanation should
be sought within the framework of the Reid model, in which an earthquake is associated with the
destruction of cohesion on the boundary of two adjacent plates [Reid H.F. The California earthquake of
April 18 1906. Vol. 2. The Mechanics of the earthquake. The Carnegie Inst. Washington, 1910]. The
sharp compression of rocks, preceding their destruction, will lead to the generation of an electromagnetic
pulse due to piezomagnetic mechanism. An alternative is a series of two or more pulses with a non-
uniform structure of interblock cohesion.
The results of the analysis can find application in the search and development of methods for forecasting
earthquakes in seismic regions. The repeatability of electromagnetic precursors of repeated earthquakes
gives the principal possibility of prompt notification (in a few minutes) of another earthquake.
The work was carried out with the financial support of Programs No. 7 and No. 28 of the Presidium of the
Russian Academy of Sciences and RFBR projects 16-05-00056 and 16-05-00631 and State order No.
0144-2014-00116.
117
NEW DATA ABOUT LOW MAGNITUDE SEISMICITY OF THE GAKKEL
RIDGE ON THE DATA OF CONTINUOUS REGIONAL MONITORING
Fedorenko I.V.
N. Laverov Federal Center for Integrated Arctic Research, Arkhangelsk, Russia
The Gakkel Ridge is the ultraslow spreading ridge situated in the Arctic region between Eurasian and
North-American lithospheric plates. Its spreading rate decreases from 12.8 in the west to 6.5 mm/y in the
east. According to geological and geophysical properties it is divided on three segments: the Western
Volcanic Zone (WVZ, 7°W¨C3°E), the Sparsely Magmatic Zone (SMZ, 3°E¨C29°E) and the Eastern
Volcanic Zone (EVZ, 29°E¨C128°E).
Since 2011 several seismic observation points were set on the arctic islands, such as the Franz Joseph
Land (ZFI, OMEGA) and the Severnaya Zemlya Archipelago (SVZ). This translates to representative ML
magnitude was decreased from 3.6 to 2.8. The SVZ seismic station is main contributed in monitoring of
the Eastern Volcanic Zone.
Regional monitoring process is led using the NOES travel-time curve and mainly polar stations situated
on the islands. Error ellipses were calculated for the range of earthquakes located during it. Events of the
WVZ and the SMZ with ML>3 have lager location errors than produced by teleseismic ISC location. But
in the EVZ values are comparable owing to SVZ seismic station. Most of earthquakes with ML<3 can be
located only on base of three or four stations. The NOES travel-time curve is now the best for its location
despite of large errors.
Spectral-temporal analysis was made for the earthquakes registered in the period
01.12.2011¨C01.02.2015. The lower border f1 of events energy maximum is constant and equals about 2
Hz. The upper border f2 is different. As a result, earthquakes with various f2 values are registered in all
zones. The WVZ has most low-frequency events which is consistent with its structure. The SMZ has wide
range of f2 values. But most of all events are registered with maximum energy in range of 220 Hz. The
EVZ also has a wide band of f2 values despite of presence of many volcanic centers.
Spatio-temporal analysis was also made for the period 2011¨C2017. Single-link cluster analysis was the
first used method. By this technique 4 seismic swarms were found in the WVZ and EVZ. The second
used algorithm was created by Molchan and Dmitrieva and realized in the program of V.B. Smirnov for
detection of aftershock sequences. As a result, no aftershock sequences were found.
Thus opening of new seismic observation points large contributed in seismic monitoring of the Gakkel
Ridge. But next improvement of observation system is need.
This work was made with partial support of RFBR grant 18-05-70018.
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SEISMICITY AND CRUSTAL STRUCTURE OF THE SOUTHERN CRIMEA
AND ADJACENT NORTHERN BLACK SEA FROM LOCAL SEISMIC
TOMOGRAPHY
Gobarenko V.1, Yegorova T.
2
1 Institute of Seismology and Geodynamics, Vernadskii Crimean Federal University, Crimea,
Simferopol, prosp. akad. Vernadskogo 4, 295007 Russia
2 Institute of Geophysics, National Academy of Sciences of Ukraine, Kiev, Pr. Palladina 32, 03680
Ukraine
[email protected], [email protected]
The Greater Caucasus and the Crimea Mountains constitute a fold-and-thrust belt that formed at the
southern margin of Eurasia as a result of Cenozoic collision between Eurasia and the Africa–
ArabianPlate. The Main Caucasus Thrust (MCT), which marks the southern boundary of the Greater
Caucasus orogen, can be traced westward along the northern margin of the Black Sea and southern
Crimea and coincides with a zone of seismicity called the Crimea Seismic Zone (CSZ). The CSZ is
characterized by earthquakes of M=3-5 with foci in the crust and uppermost mantle with abundant weak
seismi
regional compression and transpression within the continental margin at the transition from continental
crust to the “sub-oceanic” crust of the Black Sea.
Weak seismicity was used to recover the velocity structure of the crust of southern Crimea Peninsula and
adjacent northern Black Sea employing local seismic tomographic techniques. Events were recorded
during 1970–2013 by nine stations on the Crimea peninsula (Crimea Seismic Network; CSN) and by one
station (Anapa) on the Caucasus coast of the eastern Black Sea. Data for the tomographic inversion were
relocated for the P- and S-wave arrivals at all permanent stations of CSN. Earthquake relocation was done
via error minimisation starting with a 1-D reference velocity model based on seismic surveys (active and
passive) in the study area.
The new local tomographic results document significant P- and S-wave velocity heterogeneities in the
depth range 10-30 km. Stable solutions have been obtained for depths of 15, 20 and 25 km. A distinctive
feature of the crust of southern Crimea is its clear division on two domains: a western domain (Crimean
Mountains) and an eastern one (Kerch-Taman zone). They are separated by a linear low-velocity zone of
~N-S strike (in the area between Sudak and Feodosiya) interpreted as a zone of crustal weakness that has
been repeatedly reactivated. It could possibly be related to a collinear Proterozoic N-S trending fault zone
in the Ukrainian Shield and/or a normal fault zone related to Early Cretaceous rifting and opening of the
East Black Sea Basin.
Interpretation of velocity anomalies suggests a complex 3-D crustal geometry that involved a change of
underthrusting polarity in the western Crimea Mountains crust compared to eastern Crimea. This may be
a reflection of structural inheritance and reactivation during compression of the same deeper structures
that earlier controlled formation of the mid-Black Sea Ridge during Black Sea extension.
119
APPLICATION OF THE RECEIVER FUNCTION TECHNIQUE IN AREAS
WITH A LOW-VELOCITY NEAR-SURFACE LAYER
Goev A.G.1, Kosarev G.L.
2, Sanina I.A.
1
1 Institute of Geosphere Dynamics RAS, Moscow
2 Schmidt Institute of Physics of the Earth RAS, Moscow
Low-velocity layers, or a zone of low velocities, are present almost at any point of the Earth's surface. It
can be water, soil, ice, sedimentary layers of various nature, a destroyed bedrock, and perhaps something
else not mentioned in this list. In our case, this can be a solid or loose or even semi-liquid rock with a
velocity of P waves less than 4 -5 km / s. The depths of the relatively low velocities zone could vary first
meters up to 10-20 km. The horizontal extent of the zone of low velocities is also important. It must be
greater than or equal to the size of the first Fresnel zone when calculating the distance from the
observation point. The receiver function method is used in those modifications where the velocity section
of the low velocity zone or the velocity section of the earth's crust is determined, or the velocity section of
the earth's crust plus the upper mantle to depths of about 300 km.
The Eastern European Craton (EEC), and in particular the Moscow Syneclise, is an example of the almost
ubiquitous spread of the near-surface zone of low velocities, or the sedimentary layer, separated from the
crustal rocks of the Earth as a rule by a sharp boundary. An example of a region where, at most
observation points, is no low-velocity zone, significant for the receiver function techniques is the Baltic
Shield. The receiver functions obtained at the observation points with the low-velocity zone differ
significantly from the receiver functions obtained at points where there is no sedimentary layer. The most
noticeable feature in the waveform of the receiver function obtained in the low-velocity zone is the large
amplitude of the converted PS wave from the sediment boundary-the foundation. In the Moscow
Syneclise, the amplitude of this wave is twice that in comparison with the hypothetical situation of the
absence of a sedimentary layer in this region. The record is an increase in the amplitude of a similar wave
four times in Calcutta, located on a very powerful and low-speed sedimentary layer. Another important
obstacle arises is interference between the single multiple wave P-Moho boundary-S and two or three-
fold P2S and 2PS waves. This interference makes it almost impossible to visually determine a first
multiple wave from the Moho boundary on the receiver function and greatly complicates the process of
inversion of the receiver function in the velocity section.
Given research goes in details of the formation of the receiver function from separate converted and
multiple waves for the simplest models of the medium and analyzes the ways of overcoming the
difficulties arising by the interference of single and multiple converted waves. Examples of inversion of
receiver functions to velocity sections are given.
This work was supported by the RFBR grant 17-05-01099.
120
HIGH-SENSITIVITY SENSOR FOR CORRECTION OF INSTRUMENTAL
THERMAL NOISE OF SEISMIC DEVICES
Gravirov V.V. 1, 2
, Kislov K.V. 1
, Likhodeev D.V.2
1 Institute of Earthquake Prediction Theory and Mathematical Geophysics of the Russian Academy
of Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow 117997, Russia, Tel.:
+7 (495) 333-4513
2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS),
http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56.
One of the main noise-causing factors in long-period seismometry is temperature fluctuations of
mechanical elements of devices, as well as temperature oscillations in their interior space. To reduce such
noise it is possible to apply adaptive filtering of seismic signal with a support on elements temperature
registration. However, to date, this way it was not possible to achieve significant results since there were
no systems capable of recording temperature changes with sufficient accuracy. The developed high-
sensitivity thermal sensor is capable of simultaneously monitoring the temperature at several of the most
important points of any seismic device with an accuracy of about 0.005 degrees Celsius.
PEMSDAS - PORTABLE EXPANDABLE MODULAR SEISMIC DATA
ACQUISITION SYSTEM
Gravirov V.V. 1, 2
, Kislov K.V. 1, Sobisevich A.L.
2, Sobisevich L.E.
2
1 Institute of Earthquake Prediction Theory and Mathematical Geophysics of the Russian Academy
of Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow 117997, Russia, Tel.:
+7 (495) 333-4513
2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS),
http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56.
One of the problems of seismic data registration is the need to provide a huge input dynamic range. We
have developed a new small-size low-power data acquisition system based on a 24-bit analog-to-digital
converter. The system does not require permanent connection to a PC and has a low cost. It is built on a
modular-block principle that allows ones to flexibly change as the number of completely independent
input data channels used and the type/model of the controller in accordance with the requirements of tasks
being solved. A variant of constructing data acquisition system functioning on the base of a Raspberry Pi
3 microcomputer will be present as one of the possible configurations. This system will be especially
useful for working as part of mobile seismic stations.
121
ATLAS OF THE AFTERSHOCKS: TO THE 150th ANNIVERSARY OF
FUSAKICHI OMORI
Guglielmi A.V.1, Zotov O.D.2, Zavyalov A.D.1
1 Institute of Physics of the Earth, RAS, Moscow, Russia
2 Borok Geophysical Observatory of Institute of Physics of the Earth, RAS, Borok Yaroslavl, Russia
Our work is devoted to the memory of the outstanding Japanese scientist. In 1896, Fusakichi Omori
discovered the law of the aftershocks evolution that bears his name. We propose a new approach to
processing and analyzing the flow of aftershocks after the main shock of a strong earthquake. It is based
on the nonlinear differential equation of aftershocks, which has the form of a shortened Riccati equation.
The coefficient s in front of the quadratic term of the aftershock equation has the meaning of the
deactivation factor of the earthquake source after the formation of the main discontinuity. For s = const,
the aftershocks equation is completely equivalent to the hyperbolic law of Omori. A hypothesis has been
put forward that the known deviations of the frequency of aftershocks from the hyperbolic law are due to
the nonstationarity of the earthquake source after the formation of a main discontinuity in the continuity
of rocks. The relaxation model of the source in which the deactivation coefficient s(t) depends on time is
proposed. By using aftershocks equation, we posed and solved the inverse problem of physics of the
earthquake source. This allowed us to determine the deactivation factor s(t) by using the observation of
the frequency of aftershocks. We compiled the atlas of aftershocks after a series of strong earthquakes.
The atlas contains a description of the parameters, the original sequence of aftershocks, and the function
s(t) for each event. The analysis of the atlas showed a rich variety of the evolution forms of the
earthquake source after the main shock. Our work was partially supported by the Program 28 of the
Presidium of RAS, and RFBR project 18-05-00096.
NEW MACROSEISMIC MANIFESTATIONS OF EARTHQUAKES IN THE
VRANCH AREA ON THE TERRITORY OF UKRAINE
Ilyenko V.A., Kushnir A.N.
Institute of Geophysics by S.I.Subbotin name, National Academy of Science of Ukraine, Kiev
In abstract the macro-seismic impact of seismic-active Vrancea Zone (Romania) on territory of Ukraine,
on example of earthquake that occurred on September 23, 2016 at 23.11 GMT with magnitude of 5.6, is
described. Location of seismic event is characterized by following geographic coordinates - 45.71°N,
26.59°E, and was located at distance of 8 km from Nerezhu commune that belongs to Vrancea county.
A considerable part of the Ukrainian territory is under influence of the earthquakes, which take place in
the Vrancea zone in Romania (area of the joint between the Eastern and Southern Carpathians). Focuses
of the earthquakes, which are capable to become the reason of macroseismic manifestations on the
territory of Ukraine, are located in the mantle at depths ranging from 80 to 190 km. Maximum
magnitudes of earthquakes in this zone reached 7.6 points.
At analyzing of quantity of earthquake in Vrancea zone in period of years 2000 - 2014, their cycle change
with period of three years can be traced, except for years 2011-2012, when decrease of events quantity
was not observed. In years 2000-2003 the quantity of earthquakes constantly increased, at this their peak
122
occurred in 2002. In general, since year 2000 at territory of Romania occurred approximately 13
earthquakes with magnitude of 5 and more.
Due to the fact that one of the last earthquakes of September 23 was noticeable at a large part of Ukraine,
for description and documentation purposes of its macro-seismic manifestations the questioning was
conducted in accordance to SCS B.1.1-12:2014 of Ukraine. By means of Google form service the
electronic questionnaire was created and distributed among respondents on territory of Ukraine, Romania
and Moldova. In result of questioning 634 filled questionnaires from more than 35 cities and villages
were received.
In result of questioning and further processing of questioning results, two zones that are characterized by
macroseismic manifestations of earthquake and correspond to five and four points by MSK-64 scale were
distinguished.
SOME REMARKS ON THE SEISMOMETRIC EXPERIMENTS TAKING INTO
ACCOUNT THE THICKNESS OF THE FROZEN LAYER SOIL
Kislov K.V.1, Gravirov V.V.
1, 2
1 Institute of Earthquake Prediction Theory and Mathematical Geophysics of the Russian Academy
of Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow, 117997, Russia, Tel.:
+7 (495) 333-4513
2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS),
http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56.
Methodical studies of seismic wave propagation in shallow seismology remain relevant, since the
accuracy of the observations depends on the correct interpretation of the data. The frozen soil layer
thickness monitoring is necessary for many scientific objectives and applications. The soil frost level
affects the accuracy of seismoacoustic methods in mining, seismoacoustic logging, engineering-
geological surveys used for study the structure of geological formations, coal-seam fractures, assessment
of the geological environment stress state, and shallow tomography. While the effect of soil temperature
on the velocity of seismic waves has been investigated quite fully, the issue of waves attenuation
depending on the thickness of the frozen layer remains a problem. The electrical properties of frozen soils
have not been sufficiently measured yet.
Hence, there is a need for creation of a measuring system, which, depending on the tasks will be able to
produce different data set satisfying the necessary accuracy in the vertical, with the necessary discreteness
in time, remotely and automaticaly. The ELFREEZMETER - electronic freezemeter has been developed
for studying of influence of the frozen soil layer thickness on a seismic signal.
But when ones working with almost any new system, naturally there are methodical difficulties, so we
present some considerations on the representativeness of freezemeter data when they use in seismological
experiments.
123
ON THE QUESTION OF THE ROTATIONAL SEISMOLOGY
Kislov K.V.1, Gravirov V.V.
1, 2
1 Institute of Earthquake Prediction Theory and Mathematical Geophysics Russian Academy of
Science (IEPT RAS), http://www.mitp.ru, Profsoyuznaya str. 84/32, Moscow, 117997, Russia, Tel.:
+7 (495) 333-4513
2 The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS),
http://www.ifz.ru, B. Gruzinskaya,10, Moscow, 123242, Russia, Tel.: +7 (499) 766-26-56.
No one has no doubt now the existence of rotational components of motion during an earthquake. It is a
fact that interest in this potentially new field for seismology has risen during the last years. However,
often even seismologists have questions: What does rotational seismology mean, what is magic for, what
hardware it has, what it can give now and what can it achieve? Are measurements of rotational ground
motions useful for seismology? Here we have decided to answer these questions concisely.
Both the near-field and teleseismic rotational motions must be broken down and treated separately. It is
caused not only weakening of movements at distance, and, consequently, the difference of
instrumentation. To understand strong ground motions we must deploy extensive seismic instrumentation
along active faults. Teleseismic registration so far also open more questions and create more difficulties
than it purported to solve.
SEISMICITY IN THE AREA OF NORTH SEA ROUTE
Konechnaya Y.V.1, Fedorenko I.V.
2
1 – United Geophysical Survey, Russian Academy of Sciences, Obninsk, Kaluga oblast, 249030,
Russia
2 – N. Laverov Federal Center for Integrated Arctic Research, Arkhangelsk, 163000, Russia
The North Sea Route (NSR) is an important transport route for Russia, whose security is the highest
priority. A complex of observations is carried out on the territory such as meteorological and
hydrological. Seismological data are not included in this system yet, although regional earthquakes and
ice scrubs can significantly alter the spatial dynamics of the ice cover.
At present time, gas and gas-condensate as well as oil and oil-condensate fields are discovered on the
territory of the Barents and Kara Seas. In total, 58% of undiscovered reserves and 43 of 61 large fields are
located in the Russian Arctic sector. In connection with the increase in hydrocarbon production, cargo
transportation along the NSR is also developing. It is recognised that the area of the Northern Sea
transport route in the Western part of the Russian Arctic is aseismic. According to data from international
services within period 2000-2017, in the European sector of the Arctic about 9,300 earthquakes have been
registered, some of which occur in the area of the NSR.
We note an increase of seismic study in the area of the NSR after the opening of the seismic observation
point on the Severnaya Zemlya archipelago in November 2016. More than 400 regional earthquakes and
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16 local events were recorded during the first year of operation. The value of the local magnitude of
earthquakes is in the range from 1.2 to 4.9.
A feature of the Arctic seas is their long freezing and the formation of a huge ice cover. The maximum ice
thickness is created in the area of the Severnaya Zemlya archipelago, in particular in the Vilkitski Strait
through which passes NSR. It is significant that this area is characterized by modern seismicity.
Earthquakes (both natural and caused by anthropogenic activities) can affect ice formation, and the
formation of glaciers that prevent navigation results in the disruption of coastal pipelines.
Currently, the representative level for Arkhangelsk seismic network for the given region is M=2.7. Weak
seismic events allow us to expand our understanding of tectonic processes, which is very important for
the Arctic regions, which are fragmentarily investigated, even to the point that even seismic zoning of
different scales, there are "white spots", especially for shelf areas.
This work was carried out by support of the Grant of the Young Scientists of Pomorie No. 05-2018-03a
and partially by the Russian Foundation for basic research ( 18-35-00021).
POSSIBLE SHORT-TERM IONOSPHERIC PRECURSORS OF STRONG
CRUSTAL EARTHQUAKES
Korsunova L. P.1, Legenka A. D.
1, Hegai V. V.
1
1-Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Russian
Academy of Sciences (IZMIRAN), Troitsk, Moscow, Russia
We have studied changes in the ionosphere prior to crustal earthquakes with magnitudes of М ≥ 6.5 based
on the data from the ground-based stations of vertical ionospheric sounding in Japan for the period 1968–
2004 (32 cases). The data are analyzed based on hourly measurements of the virtual height and frequency
parameters of the sporadic E layer and critical frequency of the regular F2 layer over the course of three
days prior to the earthquakes provided that strong geomagnetic disturbances are absent. In the studied
intervals of time before all earthquakes, anomalous changes were discovered both in the frequency
parameters of the Es and F2 ionospheric layers and in the virtual height of the sporadic E layer. The
changes were observed on the same day at stations spaced apart by several hundred kilometers. A high
degree of correlation is found between the lead-time of these ionospheric anomalies preceding the seismic
impact and the magnitude of the subsequent earthquakes. It is concluded that such ionospheric
disturbances can be short-term ionospheric precursors of earthquakes.
HETEROGENEITIES OF THE EARTH'S INNER CORE BOUNDARY FROM
DIFFERENTIAL MEASUREMENTS OF PKIKP AND PCP SEISMIC PHASES
Dmitry Krasnoshchekov, Vladimir Ovtchinnikov
Institute of Dynamics of Geospheres, Russian Academy of Sciences, Russia 119334 Moscow Leninsky
pr. 38 korp.
The Earth's crystalline inner core (IC) solidifies from the liquid Fe alloy of the outer core (OC), which
releases latent heat and light elements sustaining the geodynamo. Variability in solidification regime at
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the inner core boundary (ICB) may result in compositional and thermal multi-scale mosaic of the IC
surface and dissimilarity of its hemispheres. Both the mosaic and hemisphericity are poorly constrained,
not least due to a lack of available sampling by short-period reflected waves. Measured amplitude ratio of
seismic phases of PKiKP and PcP reflected, respectively, off the inner and outer boundary of the liquid
core, yields direct estimate of the ICB density jump. This parameter is capable of constraining the inner–
outer core compositional difference and latent energy release, but is not well known (0.2–1.2 g/cub. cm),
and its distribution is obscure. Travel time measurements of PKiKP and PcP waveforms can be useful in
terms of getting an insight into fine structure of ICB and its topography. We analyse a new representative
sample of pre-critical PKiKP/PcP differential travel times and amplitude ratios that probe the core’s spots
under Southeastern Asia and South America. We observe a statistically significant systematic bias
between the measurements collected in western and eastern hemispheres, and carefully examine its origin.
Separating the effects of core-mantle boundary and ICB on the measured differentials is particularly
challenging and we note that a whole class of physically valid models involving D’’ heterogeneities and
lateral variation in lower mantle attenuation can be employed to account for the observed hemisphericity.
However, we find that variance in PKiKP-PcP differential travel times measured above the epicentral
distance of 16 degrees is essentially due to mantle heterogeneities. Analysis of data below this distance
indicates the ICB density jump under Southeastern Asia can be about 0.3 g/cub. cm, which is three times
as small as under South America where also the thickness of the above liquid core can be by 1-3 km in
excess of the one in the East. The findings preclude neither IC hemispherical asymmetry (whereby
crystallization dominates in the West and melting in the East) nor patchy IC surface, but provide an
improved and robust estimate of the ICB density jump in two probed locations.
RADIAL ANISOTROPY OF THE EUROPEAN UPPER MANTLE FROM
RECORDS OF EARTHQUAKES AND SEISMIC NOISE
E.L.Lyskova, T.Yu.Koroleva, T.B.Yanovskaya
St. Petersburg State University
Radial anisotropy of the upper part of the Earth results in impossibility to satisfy dispersion curves of
Rayleigh and Love waves by a unique S-wave velocity-depth curve. Rayleigh wave dispersion curves
correspond to SV-wave velocities, whereas Love wave curves are responsible for SH velocities.
Anisotropy coefficient is defined as a relative difference between SH and SV velocities. Analysis of
Rayleigh and Love wave dispersion curves along oceanic paths has shown that in the oceanic upper
mantle Vsh>Vsv up to ~200 km. This inference was obtained easily because the oceanic crust and upper
mantle are almost homogeneous laterally. However the data on anisotropy under continental regions are
rather discrepant due to considerable lateral heterogeneity of the continental crust and upper mantle. To
estimate the anisotropy coefficient under continents it is necessary to apply the tomographic inversion
separately to Love and Rayleigh wave dispersion curves, and to compare the corresponding S-wave
velocity-depth curves in the same points. However, this approach leads to considerable errors, because
velocity values obtained from the tomography are not local: they are averaged over rather spacious areas
that are usually different for Love and Rayleigh waves.
To overcome this drawback we applied surface wave tomography directly to anisotropy coefficient for
each wave path rather than to dispersion curves separately. The dispersion curves are determined in the
period range 10–100 s from records of earthquakes and from cross-correlation functions of seismic noise
between pairs of seismological stations. For each path the dispersion curves of Rayleigh and Love waves
are inverted to the SV and SH velocity-depth curves. Then path anisotropy coefficients are estimated
from these curves as averaged in several depth intervals: in the crust and in three 30–km intervals in the
upper mantle.
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Finally tomographic inversion was applied to the path anisotropy coefficients in the selected depth
intervals. The most reliable results were obtained for the two upper layers in the mantle. It was found that
in central Europe the anisotropy coefficient is close to zero and maybe even slightly negative, whereas at
the periphery of the study area (Baltic, Mediterranean, Black sea) it is positive and close to that for the
oceanic regions (3–4%).
This study was supported by the RFBR research grant No. 17–05–00522.
SOFTWARE SERVICE «SEISMOLOGY ONLINE»
Mikhailova Yana1, Morozov Alexey
2
FSIoS FRCCSoA RAoS
1 [email protected], 2 [email protected]
“Online Seismology” Software was developed and applied for the assessment of seismic hazards of
Arctic archipelagoes of Svalbard, Franz Josef Land and Novaya Zemlya.
Online Seismology software is designed to be accessed online by multiple users through a web-browser.
This software is based on a consolidated earthquake catalogue covering the period from the early 20th
century to 2018. The following sources contributed to the compilation of the catalogue:
Seismic catalogue of the Arkhangelsk Seismic Network;
Seismic catalogue of the field station that operated on the island of Alexandra Land of Franz Josef
Land from 1969 to 1970 (Avetisov, 1971);
Specialized earthquake catalogue of Northern Eurasia (SECNE, Kondorskaya, Ulomov
(Special¡K, 1996, Ulomov at al. 1996));
International Seismological Center catalogue (www.isc.ac.uk) that compiles data from various
seismological centers;
Catalogue of the NORSAR seismological agency (www.norsardata.no);
Catalogue of the Norwegian National Seismic Network (www.geo.uib.no/seismo/). The catalogue is updated through automatic /semiautomatic import of data from the data sources.
For ease of data analysis and selection, this software service allows to maintain a list of user-defined
geographical zones. Boundaries of such geographical zones can be set both graphically and by specifying
the nodes manually.
The data output option enables the user to view a list of seismic events or save it to a file (supports
formats - MS Excel, pdf, etc.).
A model for conversion of all types of magnitudes calculated by various seismological centers to the
unified magnitude was developed as part of the consolidated catalogue compilation process.
This software tool is designed to calculate seismic activity and tremor rate.
Events selected from the consolidated earthquake catalogue as well as seismic activity and tremor rate
calculation results can be visualized with ArcGis in 3D scenes and 2D maps.
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GEODYNAMICS OF THE EAST-EUROPEAN CRATON BASED ON UP-TO-
DATE GNSS DATA
A. V. Mokhnatkin1, V. L. Gorshkov
1, N. V. Scherbakova
1, B. A. Assinovskaya
2
1 CAO RAS (Pulkovo Observatory)
2 FRC RAS (Federal Research Center of RAS), Geophysical Survey, Pulkovo Seismic Station
The new database of GNSS velocities for the stations on the East European Craton (EEC) has been
recently compiled using various data sources. Present database contains data for more than 300 stations
having observations which last two years and more, including plenty of Russian stations. These data have
free access and can be used for the further geodynamics research of the region. The dense network of
gathered GNSS stations contributes the kinematic study of EEC, especially for surroundings of the Gulf
of Finland.
The EEC basement is formed by the combination of numerous geological structures which have different
age, heterogeneous composition and different history of geological development. In particular, the
basement of EEC has two crystalline shields: Baltic (BS) and Ukrainian, separated by the Russian Plate
(RP), having powerful sedimentary cover. The western part of RP has various extensional structures, that
correlates with the strain data provided by GNSS measurements.
Angular velocities of BS and RP solid-body rotation were evaluated. Since the NW part of Europe is
subject of the post-glacial uplift (PGU), the corresponding model corrections were used for the velocity
field assessment. The difference in rotation of these blocks is statistically insignificant (BS: 0.257+-0.002,
RP: 0.254+-0.003 deg/Ma), whereas deformation field modelled for the especially dense GNSS net
surrounding the Gulf of Finland region shows a weak (2-3 nanostrein/year) compression in the direction
from NW to SE. The field of vertical velocities without PGU elimination has a drastic shift from
elevation to depression at the border of two blocks. The horizontal deformation field at the junction zone
of RP and BS reflects the structure of the basement. There are stand out the Novgorod granitoid intrusion
at the centre and numerous aulacogens where the horizontal compression changes its direction. This fact
is evidence of the current geodynamic activity of the region, which can be realized both in the form of
weak earthquakes and plastic deformations. There were already several seismic events caused by faulting
at Paldiski-Pskov seismogenic zone, that adjacent to the Western part of the region, during 2018.
Present conclusions correspond with data on negative vertical deformations which prevail, despite the fact
that this area has to be exposed to post-glacial rebound.
NATURAL AND TECHNOGENIC SEISMIC AND GEODYNAMIC ACTIVITY
OF THE SOUTHERN URALS
Nesterenko M. Yu.
Orenburg Scientific Center of Ural branch of Russian Academy of Sciences
Monitoring and investigation of the geodynamic state performed by the Department of Geoecology of the
Orenburg Scientific Center of the Ural Branch of the Russian Academy of Sciences in the Orenburg Pre-
Urals made it possible to obtain conclusions about the level of seismic activity within the platform part of
the Orenburg region. In addition to natural seismicity, technogenic seismicity becomes an important
factor, the role of which increases with the increase in oil and gas production at the exploited fields. The
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geodynamics of the Southern Urals is poorly understood, because the region is located on a platform, that
are traditionally called geodynamically inactive and weakly seismic. The focus was on active mountain-
folded structures. However, in recent years, according to a number of seismologists and geologists,
interest in studying the geodynamics of platform areas has increased significantly after it was discovered
that the platforms are quite mobile, especially near folded areas.
Natural seismic activity caused by a advances crustal blocks relative to each other according to the block-
layered structure of the crust. However, triggered seismicity also gets discharged through existing mobile
zones.
In conditions of natural geo-and hydro-geodynamic processes, block-fault structure of the earth's crust,
intensive oil and gas production in large oil and gas bearing areas disrupts the natural, including
geological, environment, significantly transforms hydrodynamic and geodynamic processes in the earth's
crust to depths of up to ten kilometers or more on areas up to several thousand square kilometers.
Conditions are created for the emergence of a number of environmental problems that significantly affect
the development of nature and the livelihoods of the population in the region.
Complex researches of geodynamic and seismic activity in the Southern Urals revealed and explore the
laws of formation of the modern tectonic processes in natural and anthropogenically modified conditions.
The layered-block structure of the earth's crust leads to an inhomogeneous distribution of stresses and to
their concentration in the contact points of the blocks. The main influence on the natural stress-strain state
of the Earth's interior is exerted by gravitational forces and tectonic processes. The developed
methodology for monitoring the geodynamic state of the geological environment using global satellite
navigation systems and seismic stations is based on an integrated approach that takes into account the
interaction of geological structures, dynamics of the hydrogeosystem, extraction of minerals, and the
stress-strain state of the earth's crust. Comparative analysis of the geological structure, fault system, the
dynamics of groundwater, stress-strain state of the earth's crust and the seismicity of the region allowed to
regionalize the territory of geodynamic and seismic activity.
ANALYSIS OF THE SPATIAL DISTRIBUTION OF THE EARTHQUAKE
FOCAL MECHANISMS IN THE KURIL-OKHOTSK REGION
Polets A.Yu.
Institute of Marine Geology and Geophysics Far Eastern Branch Russian Academy of Sciences
One of the main parameters which characterize the seismic event is the earthquake focal mechanism. A
spatial analysis of the earthquake focal mechanisms in the Kuril-Okhotsk region was carried out on the
basis of the Global CMT Project data. A new catalog was created for the region of 43¨C600 N and
139¨C1650 E. The observation period was from 1976 to 2018. The catalog included 1822 seismic events
with moment magnitudes from 4.7 to 8.3.
The maximum depth of events is 690 km; the most representative range of earthquake magnitudes is from
5.0 to 6.0; the major part of the earthquakes for which were determined the focal mechanisms are located
at depths of 0-60 km according to the initial seismological data analysis.
In order to analyze the types of earthquake focal mechanisms we used the classification, which is usually
applied for selecting the geodynamic regimes of deformation during the state of stress analysis [Rebetsky,
2007]. The main types of earthquake focal mechanisms are reverse, strike-slip fault and normal fault. The
intermediate types are the combination of strike-slip with revers or with normal faults, and the shift along
the subvertal nodal plane.
Analysis of the catalog shows that it contained 1010 (55.4%) reverse events, 157 (8.6%) normal faults, 97
(5.3%) strike-slip faults, 370 (20.3%) strike-slip with revers and 188 (10.3%) strike-slip with normal
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faults. The analysis of the earthquake focal mechanisms within the 11 depth levels has shown that reverse
is a prevalent type for depth 0-30 km (452 events (65 %)) and for 30-60 km (488 events (75%)). Reverse
(48 events (34%)) and reverse with strike slip (52 ñîáûòèÿ 37%) are typical at depths of 90-120. Strike-
slip with revers or strike-slip with normal faults are common for the depth 120-700 km.
Thus the prevalent areas of different types of Kuril-Okhotsk earthquake focal mechanism are determined
for different depth levels.
The reported study was partially supported by the Grant of the President of the Russian Federation,
research project MK-2421.2017.5 and by RFBR, research project No.17-05-01251 a.
FEATURES OF THE TECTONIC STRESS FIELD IN THE OKHOTSK SEA
AND JAPANESE REGIONS
Polets A.Yu.
Institute of Marine Geology and Geophysics Far Eastern Branch Russian Academy of Sciences
The Kurile-Okhotsk and Japanese regions are characterized by a high level of seismicity. Earthquakes
with a moment magnitude over 8.0 may occur here. The Kuril-Okhotsk region is located at the junction of
three major lithospheric plates – the Eurasian, Pacific and North American (the Okhotsk microplate). The
Japanese region is located at the junction of four lithospheric plates - the Eurasian, Pacific, North
American and Philippine Sea plate. The high seismicity of the studied regions is due to the intensive
geodynamic interaction of the lithospheric plates.
The method of cataclastic analysis of discontinuous displacements was used to reconstruct the modern
state of stress parameters in the investigated regions. The worked catalogs were created on the basis of
Global CMT Project data. The seismic data processing was carried out in the long-period reconstruction
mode at the grid nodes 0.50x0.5
0 for different depth levels. The number of events in a homogeneous
sample set of earthquake focus mechanisms were from 6 to 10.
The orientation of the principal stress axes and the Lode-Nadai coefficient or stress ratio, which
characterizes the shape of the stress ellipsoid, are evaluated during the first stage of the MCA [Rebetsky,
1996, 1999]. The extreme values of the Lode-Nadai coefficient (+1 and -1) correspond to the states of
uniaxial compression and extension, and the zero value for pure shear. The main type of the stress tensor
for the studied regions is the pure shear and its combinations with uniaxial compression.
A characteristic feature of the stress field of the investigated regions is the orientation of the principal
stress axes. In the Kuril-Okhotsk region, the projections of the principal stress axes of maximum
deviatoric compression (σ3) and extension (σ1) oriented almost orthogonally to the Kuril trench. The axis
of maximum compression dips under the oceanic plate and the axes of maximum extension dips under the
continental plate. In the Japanese region, the principle stress axes also oriented almost orthogonally to the
axis of the oceanic trench, with the exception of the area along the Nankai segment of the Philippine Sea
plate.
Data on the orientation of the principal stress axes and the vector to the zenith made it possible to make
zoning by the types of the geodynamic regime. In the Kuril-Okhotsk and in the Japanese regions the
prevalent geodynamic regime is horizontal compression but it changes with depth. The most stable
prevalent geodynamic regime is at depth of 30–60 km for both regions. In the Japanese region, there are
large areas of horizontal extension to the east of the oceanic trench. It should be added that this regime
was existed here before the 2011 Tohoku earthquake The horizontal shift is along the Nankai trench zone.
The trajectories of the underthrust shear stresses determine the direction of action on the bottom of the
earth’s crust from the upper mantle. Such orientation of the principal stress axes is common for the
subduction zones and it determines as the active force the underthrust shear stresses. The underthrust
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shear stresses, which acting normally on a horizontal plane pointed towards the center of the earth,
determines the corresponding type of motion of the subcrustal lithospheric substance as active force of the
present stage of the tectonic process. The stable orientation of the underthrust shear stresses is observed at
the depth 0-300 km, but with increasing depth (300–700 km) the orientation of theses axes sharply
changes to the opposite direction.
Zoning of the intensity of the dilatancy process was carried out based on the results of the stress
inversion.
In the Kuril-Okhotsk region, the most intensive dilatancy processes are now occurring in the earth's crust
near Kamchatka and along the southern part of the Kuril Island. Low rates of dilatancy loosening can be
observed in the central part of the Kuril Island and near Hokkaido Island. In the Japanese region,
extensive areas with an increased rate of dilatancy are present in the earth's crust east of the northern part
of Honshu Island, south of the Tokyo Bay and Okinawa Island. The rate of dilatancy is generally low in
the earth crust of the Honshu Island.
The reported study was partially supported by the Grant of the President of the Russian Federation,
research project MK-2421.2017.5 and by RFBR, research project No.17-05-01251 a.
SPLITTING OF EARTH'S FUNDAMENTAL SPHEROIDAL MODE 0S2 IN
GEOMAGNETIC VARIATIONS
Riabova S.A., Spivak A.A.
Institute of Geospheres Dynamics of Russian Academy of Science
4. There are two separate types of free oscillations of an Earth - spheroidal (S) and torsional (T)
(sometimes called toroidal). Torsional oscillations have tangential but no radial displacements.
Since the dilatation is zero, torsional oscillations cause no disturbances in density and hence no
changes in the gravitational field. Thus any instruments designed to measure small fluctuations in
gravity cannot record torsional oscillations. In spheroidal vibrations, the displacements have, in
general, both radial and horizontal components. The lowest frequency mode of the oscillations is
the fundamental spheroidal mode 0S2 with five components that has a period of about 54 min. It
seems promising to use geophysical fields, for example, the geomagnetic field as an indicator of
the Earth's free oscillations. As the initial data we used the results of recording the Earth's
magnetic field at the Geophysical observatory "Mikhnevo" of the Institute of Geospheres
Dynamics (54.959º N, 37.766º E), carried out in the period 2010 - 2015. Recording geomagnetic
variations during strong earthquakes allow us to detect modes 0S2. In periods of 15 days after
major earthquakes, in the absence of strong magnetic disturbances, it is possible to distinguish the
fine structure of the basic spheroidal mode of the earth 0S2 in the geomagnetic variations. The
estimated singlet frequencies of 0S2 are good agreement with theoretical ones computed for the
Earth model 1066A. This indicates that the Earth's magnetic field is very sensitive to mechanical
processes occurring in the Earth.
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DEEP VELOCITY SRTUCTURE OF THE ARCTIC REGION FROM
RAYLEIGH WAVE DISPERSION DATA
Alena Seredkina
Institute of the Earth’s crust SB RAS, Irkutsk, Russia
We study deep velocity structure of the poorly investigated Arctic region (>60° N) on the basis of surface
wave data. A representative dataset of Rayleigh wave group velocity dispersion curves (1555 seismic
paths) in the period range from 10 to 250 s was collected using a frequency-time analysis procedure. A
2D tomography technique developed for spherical surface without the sphere-to-plane transformation was
implemented to image the distributions of the group velocities at different periods. Totally, we calculated
18 maps for different periods and estimated their lateral resolution. Then, we constructed local dispersion
curves of Rayleigh waves and inverted them to S-wave velocity sections up to the depth of 500 km. The
obtained S-wave velocity model of the upper mantle was imaged in the form of horizontal distributions of
velocity variations at different depths and 2D velocity sections along the profiles crossing the main
tectonic units of the study area. Our results show some general trends in distribution of large-scale lateral
inhomogeneities which appear as zones of high velocity gradients at the boundaries of tectonic units and
local velocity minimums and maximums. The highest group and S-wave velocities are observed under the
Canadian and Baltic Shields. The Siberian and East European Platforms are also characterized by high
velocities. The lowest velocities are observed under the fold belts at the north-east of Eurasia and Alaska
and under the Bering Sea basin. We found evidences of the mantle plumes under Iceland and Jan Mayen
Islands represented by velocity minimums. The spreading Gakkel Ridge is manifested as low velocity
zone which widens at the Laptev Sea shelf. Thus, the revealed velocity anomalies are correlated with the
positions of the main tectonic structures of the study area. The results obtained are of great value for
further development of reliable geodynamical models of the Arctic region.
This work was supported by the grant of the Russian Science Foundation, project No 17¨C77¨C10037.
SUPERDEEP DRILLING AND ITS EFFECT ON THE SEISMIC MODELS OF
THE FENNOSCANDIAN SHIELD
Sharov N.V.
Institute of Geology, Karelian Research Centre, RAS, Petrozavodsk, Russia
An attempt to interpret the origin of seismic boundaries in the crystalline crust from deep drilling record
and available geological and geophysical data on the drilling area was made. Deep drilling was conducted
in several regions of the Fennoscandian Shield: Kola, Russia (SG-3), to a depth of 12262 m (1970-1990);
Gravberg (GR) and Stenberg-I, Central Sweden, to a depth of 6337 m (1986-1987); and 6529 m (1991-
1992); Outokumpu (OU), SE Finland, to a depth of 2516 m (2004- 2005); Pogranichnaya (P-1), Sredny
Peninsula, Murmansk Region, Russia, to a depth of 5200 m (2004-2006); and Onega, Central Karelia,
Russia (ON), to a depth of 3537 m (2007-2008). The results obtained were analyzed. They show
considerable discrepancies between forecast seismic-geological models and the actual structure of the
upper portion of the continental crust. Deep drilling has proved that heterogeneities in the upper portion
of the crystalline crust, indicated by geophysical data, are due to changes in the composition and physical
condition of deep-seated rocks. Therefore, even approximate rock composition cannot be ultimately
estimated from elastic wave velocity values alone. It showed the real pattern and origin of lowered elastic
wave velocity zones in the upper portion of the crust and did not show that layers become more
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homogeneous with depth. The origin of intracrustal seismic boundaries could be affected by various
factors such as variations in mineralogical composition, structural and textural differences between the
rocks and a thermodynamic setting [1].
Deep drilling provided direct data on the composition and structure of the upper portion of the crystalline
crust to a depth of 12 km. They showed that we do not know anything about the continental crust and
made us considerably revise our earlier concepts.
Deep drilling proved that the heterogeneities, identified by geophysical methods in the upper portion of
the crystalline crust, are the result of changes in the composition and physical condition of deep-seated
rocks. Therefore, even the approximate composition of the rocks cannot be ultimately determined from
elastic wave velocity values alone.
The results of the geophysical studies, conducted as part of deep drilling on the Fennoscandian Shield,
make scientists re-interpret relevant geological and geophysical data. The mineralogical composition and
petrophysical characteristics of rocks can be assessed only by deep drilling of the crystalline crust. The
objective geological-geophysical sequence of the upper portion of the earth crust can thus be constructed.
References
1. Sharov N.V. Lithosphere of North Europe based on seismic data // Petrozavodsk KarRC, RAS. 2017.
173 p.
SELF-SIMILARITY ANALYSIS OF EARTHQUAKES AND ACTIVE FAULTS
WITHIN THE SIKHOTE-ALIN OROGENIC BELT AND NEIGHBORING
AREAS
Zakharov V.S. 1,3
*, Didenko A. N. 2,4
, Gil’manova G.Z. 2
, Merkulova T.V. 2
1 – Moscow State University, Geological Faculty, Moscow, 119991 Russia
2 – Kosygin Institute of Tectonics and Geophysics, Far East Branch, Russian Academy of Sciences,
ul. Kim Yu Chena 65, Khabarovsk, 680000 Russia
3 – Dubna University, ul. Universitetskaya 19, Dubna, Moscow region, 141982 Russia
4 – Pacific National University, ul. Tikhookeanskaya 136, Khabarovsk, 680042 Russia
A comprehensive analysis of self-similarity characteristics of earthquakes and active faults within the
Sikhote-Alin orogenic belt and adjacent areas has been carried out. The main features of seismicity are
found to be determined by crustal earthquakes. Variations in density and fractal dimension De of
earthquake epicenters in the region show that the most active sections of the earth's crust are in the
Kharpi-Kursk-Priamur zone, the northern Bureya Massif, and the Mongol-Okhotsk fold system. Analysis
of the parameter b of the Gutenberg-Richter law suggests that its highest values, on the whole, correspond
to the areas of the highest seismic activity which is in the northern part of the Bureya massif and, to a
lesser extent, the Mongol-Okhotsk system.
Higher values of fractal dimension of the fault network Df are found to correspond to fold systems
(Sikhote-Alin and Mongol-Okhotsk) and lower values to basins and troughs (Sredneamursky basin and to
a lesser extent Uda and Torom basins). A correlation made between findings of fractal analysis of the
fault network and data on the current stress-strain state, established by different methods employed in
works of other authors, shows that higher values of Df occur in areas of present-day intense compression.
A good correspondence between the parameter b field and the field of Df indicates a general consistency
133
of the self-similar distribution of the earthquake magnitude (and hence energy) and the fractal distribution
of fault dimensions. Our results demonstrate that self-similarity parameters are an important quantitative
characteristic in seismotectonics and can be used for neotectonic and geodynamic analysis.
This study was supported by the Russian Science Foundation (project no. 16-17-00015). The research is
carried out using the equipment of the shared research facilities of HPC computing resources at
Lomonosov Moscow State University.
ON THE SPATIAL-TEMPORAL STRUCTURE OF AFTERSHOCK
SEQUENCES
Zotov O.D.1, Zavyalov A.D.
2, Klain B.I.
1
1Borok Geophysical Observatory, Schmidt Institute of Physics of the Earth, Russian Academy of
Sciences, Borok, Yaroslavl region, Russia
2Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
The work presents results of statistical analysis of the spatial-temporal distribution of strong aftershocks.
Data from the world catalog of earthquakes NEIC USGS from 1973 to 2014 (https://www.usgs.gov) and
from the regional earthquakes catalog of Northern California from 1968 to 2007 (http://www.ncedc.org)
were used. Short time intervals were considered - no more than 10 hours before and after main shock and
distance from the epicenter of the main shock - up to 5 degrees. The distribution of the aftershocks
number in the time-distance coordinates from the main shock was investigated. The method of
superposed epochs was used. The main shocks performed the function of reference mark for the
synchronization of sequences of repeated shocks. To each main shock was attributed the conventional
time equal to zero, and its epicenter coincided with the origin of coordinates. The main shocks with
magnitude Mms7.5 and aftershocks with 6Mas<Mms for the world catalog NEIC USGS and the main
shocks Mms5 and aftershocks with 4Mas< Mms for Northern California catalog were considered. It
is shown that the spatial-temporal distribution of strong aftershocks forms a similarity of a wave structure.
The work was supported by the Government task # 0144-2014-00116 and RFBR project # 18-05-00096.
134
STP. SOLAR-TERRESTRIAL PHYSICS
Conveners - Dr. N.V.Zolotova, Dr. A.V.Divin
Space climate and space weather
Magnetospheric phenomena
Ionosphere and upper atmosphere physics
EMPIRICAL MAGNETOSPHERIC MODELS FOR
SIR- AND CME-DRIVEN MAGNETIC STORMS
Andreeva V. A.1, Tsyganenko N. A.
1
1 – Saint Petersburg State University (SPbU), Saint Petersburg, Russia
While in general the solar wind has an extremely variable structure, during geomagnetic disturbances it
tends to arrive in the form of characteristic sequences lasting from tens of hours to days. The most
important magnetic storm drivers are the coronal mass ejections (CMEs) and the slow-fast stream
interaction regions (SIRs). Despite the fact that the CME- and SIR-driven storms are accompanied with
largely different forms of geomagnetic activity, previous data-based magnetic field models did not
distinguish between these types of the solar wind driving. In the present work we retained the basic
structure of the TA15 model [1], but fitted it to three different data samples corresponding to (1) SIR-
driven magnetic storms, (2) CME-driven storms preceded with a shock ahead of the CME, and (3) CME-
driven storms without such shocks. The storm-time dynamics of the model current systems has been
studied using the advanced parametrization method developed in TS05 [2]. The essence of the approach
was to parameterize the model with dynamical variables Wi, calculated on the basis of concurrent solar
wind characteristics and their previous history. The employed database included observations of
THEMIS, Polar, Cluster, Geotail, and Van Allen Probes missions during 156 magnetic storms in 1997-
2016.
1. Tsyganenko, N. A., Andreeva, V. A. // JGR-A 2015. V. 120. doi:10.1002/2015JA021641.
2. Tsyganenko, N. A., Sitnov, M. I. // JGR-A 2005. V. 110. doi:10.1029/2004JA010798
135
DEPRESSION OF THE TOTAL FLUX OF SOLAR ELECTROMAGNETIC
RADIATION DURING THE GENERATION OF RELATIVISTIC PROTONS
OF SOLAR COSMIC RAYS
Avakyan S.V. 1
, Nicvol’skii G.A. 2
1- All-Russian Scientific Centre “S.I. Vavilov State Optical- Institute”, 199034, Russia
2- Saint-Petersburg State University, Russia
[email protected], [email protected]
The circumstances of the discovery of a new physical phenomenon in the atmosphere of the Sun are
presented: a depression of the total flux of Total Solar Irradiance before and during the generation of
protons of relativistic energies (more than 500 MeV) of solar cosmic rays. Such events result in the
appearance of secondary cosmic particles reaching the earth's surface at sea level and are classified as
Ground Level Events / Ground Level Enhancements (GLE). On average, they are observed on Earth once
a year, and their 70-year recording by ground-based neutron monitors is now in continuous operation.
Prior to our work, this anticorrelation of the values of the TSI and GLE of SCR flows was unknown,
although it is found to be more than 80% probable. It should also be noted that the drop in the TSI value
is higher (up to 0.3%) in comparison with other events.
The discovery of the phenomenon is of fundamental importance for the physics of the solar atmosphere,
as well as sun-like stars. It is also important for solving practical issues of extra-geomagnetospheric
astronautics, especially for ensuring the safety of manned spaceflight, for example, to Mars and
potentially dangerous asteroids. The use of patrol regimes to control the level of TSI appears to be the
basis for an advance forecast of the maximum radiation hazard in the exploitation of the Moon.
We associate the physics of the open phenomenon with the development of the flare activity of the Sun,
when conditions are met for the appearance of high-temperature (more than 25-30 MK) flares in the x-ray
range, often with the location of the outbreak at the limb. In these cases:
- for the acceleration of protons in the solar atmosphere, the advantages of a lower density of the medium
(consequently, with a decrease of emission measure of electromagnetic radiation) are realized;
- the exit to the near-solar space of accelerated relativistic protons is facilitated along such a thin plasma
layer near the limb, due to the lower absorption losses.
The report suggests ways to further study the detected phenomenon, including in the interests of its
advance forecast for the safety of future interplanetary space manned flight activities
136
HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE? FORMATION
OF ASSOCIATES IN HIGH DELUTED WATER BIOSOLUTIONS UNDER
THE INFLUENCE OF THE MICROWAVE FLUX FROM THE IONOSPHERE
Avakyan S.V. 1, Baranova L.A.
2
1 - All-Russian Scientific Centre “S.I. Vavilov State Optical- Institute”, 199034, Russia
2- Ioffe Institute, 194026, Russia
[email protected], [email protected]
The purpose of our study is to consider the influence of the electromagnetic field of the environment on
the change in the structure of aqueous biosolutions, taking into account the processes of physics of
electron-molecular collisions. Until now, the assumption of A.N. Szent-Giorgui, the Nobel laureate on
physiology that: “Probably, biology did not already succeeded in understanding the main functions
because it concentrated its attention only on matter in form of particles, distinguished it from the two
matrices: water and electromagnetic field” remains relevant. In our approach, both water of organism and
electromagnetic (microwaves) radiation of environment is taken into account in the framework of
developed supramolecular physics.
Supramolecular physics describes a processes developing outside the molecules (atomic-molecular cores)
in whose evolution to the complex forms (clusters, associates) electromagnetic radiation of external origin
absorbed by exited Rydberg components of molecular complex takes part. Due to increasing value of
orbital momentum of Rydberg electrons the stability of the complex grows because probability for
forming a stable neutral cluster becomes higher as the electron more seldom penetrates into the ion core.
The report presents for the first time the following results:- it is determined that the
electromagnetic radiation absorbed in the liquid medium, which causes in it an increase in the number and
size of clusters with the participation of water molecules, can simultaneously lead to the induced emission
of these clusters at the same frequency. This is accomplished by absorption of microwave quanta by
Rydberg states, even with a greater probability than emission in spontaneous transitions. The induced
radiation is up to half of the total flux of quanta of external electromagnetic radiation absorbed by the
liquid medium and is capable of participating in further acts of increasing the growth of clusters involving
water molecules;
- attention is paid to the importance of the presence of Rydberg-excited levels in such important
biological materials as DNA, red blood cells, oligopeptides, glycopeptides, chloroplasts etc. [1]. This can
lead to a nonradiative transfer of potential energy stored in water clusters to biocomponents in impacts of
the second kind [2];
- the explanation of the effect of "large dilutions" - when in associates of some biologically active
substances associates formation is intensified [3] with water addition to the minimum concentrations (10-
15 - 10-18) M, taking into account the effect of microwave radiation of the ionosphere on the probability
of associates formation.
1. Robin M., Higher excited states of polyatomic molecules, Academic Press, 1985, V. 3.
2. Frish S.E., Optical atomic spectra, Physmatgis, 1963.
3. Konovalov A.I., Formation of nanoscale molecular ensembles in high diluted water solutions // Herald
of RAS, 2013, 83, N6.
137
HOW DOES THE GEOCOSMOS CONTROL THE BIOSPHERE?2. DNA,
IONOSPHERIC MICROWAVES AND WATER
Avakyan S.V. 1
, Baranova L.A.
2
1-All-Russian Scientific Centre “S.I. Vavilov State Optical- Institute”, 199034, Russia
2- Ioffe Institute, 194026, Russia
[email protected], [email protected]
The purpose of the work was to create model representations for describing the nature of the features
known in modern biophysics in the manifestation of the associative properties of highly dilute
biologically active solutions (see [1]), including under magnetic (metal) shielding. The task of the paper
was to show that the phenomena observed in the works of L. Montagnier, the Nobel laureate on
physiology, 2008, with the behavior of viruses (including the Human Imunodeficiency Virus) and some
bacteria [2] may be related to the impact of microwave fluxes in the first a queue of ionospheric origin, on
structure formation involving water molecules.
A well-known mechanism of associates formation is taking into account the high affinity for the proton in
water molecules. The approach developed in the Vavilov Institute is used within the framework of
supramolecular physics of over-molecular structures with participation of the neutralizing electrons in
Rydberg states [3, 4]. In the framework of theoretical physics [2] consideration of the existence of
Coherence Domains, based on Quantum Field Theory, can be regarded as an analogue of our approach.
As for water in [2] it is considered the excited state lying at 12.06 eV, which in our model representation
refers to the Rydberg state of the water molecule.
The report presents for the first time the following results:
- phenomena in highly diluted water biosolutions, including DNA [2], are associated with the effect of the
constantly existing flux of microwave radiation from the terrestrial ionosphere on the structuring of water
molecules. In laboratory experiments [1, 2], it was not taken into account that artificial magnetic shielding
by 1 mm thick layer of mu-metal absorbs also all microwaves fluxes of the environment [3, 4];
- the flux of microwaves of the ionospheric nature is modulated at Schumann frequencies in a ground-
ionosphere resonator, primarily at a frequency of about 8 Hz. Its magnitude sporadically increases during
periods of flares on the Sun and geomagnetic storms. It is shown that with calm solar-geomagnetic
activity, the fluence of the background ionospheric flux of microwaves is really needed for at least 16
hours for the manifestation of water nanostructuring [2, 4];
- structured pure water and aqueous solutions, including DNA, especially of extremely low concentrations
influenced by the microwave flux from the ionosphere, are apparently capable of emission at frequencies
below 3 kHz, taking into account the manifestation of ac Stark shift due to the interaction of the Rydberg
electron with the external "thermal" blackbody field. This hypothesis needs to be refined after analyzing
the circumstances of the experiment [2].
1. Avakyan S.V., Baranova L.A., How does the geocosmos control the biosphere? 1. Formation of
associates in high deluted water biosolutions under the influence of the microwave flux from the
ionosphere // This book.
2. Montagnier L. et al., DNA waves and water // J. of Phys., Confer. Ser., 2011, 306, 012007.
3. Avakyan S. V., Supramolecular physics of the ionosphere – biosphere links // In: Proc. of the 11th Int.
School and Conf. “Problems of Geocosmos” (Oct. 03-07, 2016, St. Petersburg, Russia) eds. V.S.
Semenov, M.V.Kholeva, S.V. Apatenkov, N.Yu. Bobrov, A.A. Kosterov, A.A. Samsonov, N.A. Smirnova
and T.B. Yanovskaya (SPb: St Petersburg State University). C. 180-186.
4. Avakyan S.V., // Herald of RAS, 2017, 87, 2.
138
INFLUENCE OF DIFFERENT IONOSPHERIC DISTURBANCES ON THE GPS
SCINTILLATIONS AT HIGH LATITUDES
V.B. Belakhovsky1, Y. Jin
2, W.J. Miloch
2
1 – Polar Geophysical Institute, Apatity, Russia
2 – Department of Physics, University of Oslo, Oslo, Norway
E-mail: [email protected] [email protected], [email protected]
In this work we compare the influence of auroral particle precipitation and polar cap patches (PCP) on
scintillations of the GPS signals in the polar ionosphere. We use the GPS scintillation receivers at Ny-
Ålesund, operated by the University of Oslo. The presence of the auroral particle precipitation and polar
cap patches was determined by using data from the EISCAT 42m radar on Svalbard. We analyzed more
than 100 events for years 2010-2017, when simultaneous EISCAT 42m and GPS data were available. For
some of the events, the optical aurora observations on Svalbard were also used. We consider the
following types of the auroral precipitation: i) the dayside and morning precipitation, ii) precipitation on
the nightside during substorms, iii) precipitation associated with the arrival of the interplanetary shock
wave. All considered types of ionospheric disturbances lead to enhanced GPS phase scintillations. For the
polar cap patches, the morning and daytime precipitation (i), and precipitation related to the shock wave
(iii), the phase scintillations index reaches values less than 1 radian. We observe that auroral precipitation
during substorms leads to the greatest enhancement of the phase scintillation index (up to 3 radians).
Thus, the substorm precipitation has the strongest impact on the scintillation of GPS radio signals in the
polar ionosphere.
ON THE CORRELATION BETWEEN LOCAL CRUSTAL MAGNETIC FIELD
OF THE MOON AND ION REFLECTION
R. Belyaev1, A. Divin
1, V. Semenov
1, I. Zaytsev
1
St. Petersburg University, St. Petersburg, 198504, Russia
e-mail: [email protected]
This work investigates the correlation between two datasets which are used to study the patches of local
crustal magnetization of the Moon’s surface, the so-called Lunar Magnetic Anomalies (LMAs). The first
dataset is a global spherical model of Lunar magnetic field with up to N=450 spherical harmonics; the
second dataset measures reflection of incident solar wind ions with 1˚x1˚ resolution. Interrelation of
reflection coefficient and the model magnetic field was studied for different geographical areas depending
on altitude. Regions with large magnetic fields have considerably more pronounced flux of scattered ions.
The correlation between magnetic field and reflection coefficient peaks at ~25-30 km above the Lunar
surface, which likely corresponds to vertical extent of the formed mini-magnetospheres. Flux of reflected
ions contains two rather different components (which are resolved by reflection coefficient), first is a
uniform anti-streaming scattered component with <<1% reflection coefficient nearly independent of
magnetic field (dominates for surface B<5 nT), and second anomalous component which dominates for
surface fields B>40 nT and which increases with magnetic field. In the medium B field range (0… 100
nT) the reflection coefficient fits the shifted hyperbolic tangent function starting from a uniform value of
~0.03-0.07% (near 0 magnetic fields) up to ~10% (anomalous reflection component typical for large >100
nT surface magnetic fields).
139
IONOSPHERE CHARACTERISTICS DURING SIMILAR GEOMAGNETIC
EVENTS
Blagoveshchensky D.V.1, Sergeeva M.A.
2, Shmelev Yu.A.
1
1 – Saint-Petersburg State University of Aerospace Instrumentation
2 – CONACYT, SCiESMEX, Instituto de Geofisica, Unidad Michoacan, Universidad Nacional
Autonoma de Mexico
email: [email protected]
The study is focused on the ionospheric response to similar geomagnetic storms. The aim was to estimate
how similar/different is the behaviour of ionopheric parameters during the storms of the similar intensity
and duration. Two pairs of similar geomagnetic storms were chosen for the analysis. Storms were
characterized by the X-component of the magnetic field and Kp-index variations. We used magnetometer,
riometer and ionosonde data (F-plots) from Sodankyla observatory (Finland). It was found that the
variations of critical frequencies of the ionospheric F2-, F1- and E-layers are not very different for the
similar storms. During the daytime hours this difference varied approximately between 0% and 11%.
During the night time hours the difference between ionospheric parameters variations depended on the
layer. It was about 4% for F2-layer and about 20% - for the sporadic Es-layer. The behaviour of the
regular E-layer at daytime during disturbances was similar to its behavour under the quiet geomagnetic
conditions. These results show that the geomagnetic storms with similar characteristics can cause the
similar effects in the ionosphere.
PERSPECTIVES OF MONITORING OF ATMOSPHERIC ELECTRIC FIELD
IN THE CENTRAL PART OF KAMCHATKA PENINSULA TO DETECT
ATMOSPHERIC-ELECTRIC EFFECTS FROM VOLCANIC ERUPTIONS
Cherneva N.V.1, Firstov P.P.
1,2, Akbashev R.R.
2, Malkin E.I.
1
1 - Institute of Cosmophysical Research and Radio Wave Propagation (IKIR) FEB RAS, Paratunka,
Russia
2 - Kamchatka Branch of the Federal Research Center «Geophysical survey RAS», Petropavlovsk-
Kamchatskii, Russia
Electric field determined by the world lightning activity, which globally forms the unitary variation with
the maximum at 19-20 UTC, has its peculiarities in each region under the influence of local factors.
Based on long-term observations at Paratunka observatory (IKIR FEB RAS), a phenomenological model
of the local atmospheric electric field (AEF) was suggested taking into account the main processes
affecting the atmospheric near-ground layer.
One of the local AEF features on Kamchatka peninsula is volcanic lightning and aero-electric structures
occurring during volcano eruptions. During explosive eruptions, when magma fragmentation occurs and a
large volume of gas and pyroclastics is emitted into the atmosphere. During eruptive cloud formation, its
electrification takes place that causes multiple lightning strokes. Investigation of the relation of lightning
strokes with eruption intensity testifies the great role of electrostatic electricity during eruptive cloud
formation. Application of systems for the observation of lightning strokes from volcanic lightning to
monitor explosive eruptions and the trajectories of their motion at the first stage is an additional method
140
of evaluation of ash hazard for air transportation. Eruptive clouds propagate for hundreds of kilometers
under the wind influence. They are aero-electric structures. The paper compares two diurnal variations of
AEF potential gradient (V’) of observation sites located in the central part of Kamchatka with continental
climate with Paratunka observatory located on the Eastern shore of Kamchatka peninsula. Cases of
responses in AEF V’ dynamics on the passage of eruptive clouds, occurring during Shiveluch volcano
explosive eruptions, are described. Recording of signals generated during eruptive cloud passage may be
one of the components of complex observations over volcano eruptions. Plan for extension of the site
network for atmospheric-electric effect recording is presented.
DEFINITION OF TEMPERATURE AND SONIC SPEED VALUES AT THE
MESOSPHERIC HEIGHTS FROM VARIATIONS OF PARTIAL REFLECTION
RADAR SIGNALS
Cherniakov S.M., Turyansky V. A.
Polar geophysical institute
During many years there were observations of partial reflected signals by the partial reflection radar of
the Polar Geophysical Institute (the observatory Tumanny, 69.0N, 35.7E) during different
heliogeophysical conditions at the heights of the D-region of the ionosphere. Temporary variations of
amplitudes of the signals during solar terminator passes which were partially reflected in the height
interval of the 75-90 km and their spectra were analyzed. It was found that the components of the time
spectrum of the variations corresponding to the resonant frequencies of the atmosphere (the acoustic cut-
off and the Brunt-Väisälä ones) in certain cases were intensified. On the basis of the theory of acoustic-
gravity waves and the empirical model NRLMSISE-00 of neutral structure and temperature of the
atmosphere identification of the experimental periods corresponding to atmospheric resonances was
executed and calculation of temperature of the neutral atmosphere and sonic speed values at the
mesospheric heights was carried out. The received results showed satisfactory consent with data of other
independent observations.
COSMIC RAY CUTOFF RIGIDITY CHANGES CAUSED BY THE
DISTURBED GEOMAGNETIC FIELD OF THE STORM IN JUNE 2015
Danilova1 O.A., Tyasto
1 M.I., Sdobnov
2 V.E.
1- St-Petersburg Filial of IZMIRAN
2- Institute of Solar-Terrestrial Physics SO RAN
Email: [email protected]
One of important factors determining the space weather are cosmic rays the cutoff rigidities of which vary
appreciably under the influence of disturbances in the interplanetary space and the Earth's magnetosphere.
This report is concerned with the changes in the geomagnetic cutoff rigidities (thresholds) of cosmic rays
computed for the period of a strong geomagnetic storm of June 2015. This disturbed period was
characterized by the solar wind speed of more than 700 km/s and Dst-index at the minimum Dst –
141
variation equal 204 nT. The theoretical vertical effective geomagnetic cutoff rigidities were calculated
for a number of stations by using the Tsyganenko TS01 model and trajectory tracing method in a
magnetic field of a disturbed magnetosphere. The theoretical cutoff rigidities were compared with the
experimental ones obtained by the global spectrographic survey method on base of the data from the
worldwide neutron monitor network.
CONJUGATE GROUND-SPACECRAFT OBSERVATIONS OF VLF CHORUS
ELEMENTS
A. G. Demekhov1,2
, J. Manninen3, O. Santolík
4.5, E. E. Titova
1
1 – Polar Geophysical Institute, Apatity, Russia
2 – Institute of Applied Physics RAS, Nizhny Novgorod, Russia
3 – Sodankylä Geophysical Observatory, Finland
4 – Institute of Atmospheric Physics, The Czech Academy of Sciences, Prague, Czech Republic
5 – Faculty of Mathematics and Physics, Charles University in Prague, Czech Republic
We present the results of simultaneous observations of VLF chorus elements at the ground-based station
Kannuslehto in Northern Finland and on board Van Allen Probe A. Visual inspection and correlation
analysis of the data reveal one-to-one correspondence of several chorus elements following each other in
a sequence. Poynting flux calculated from electromagnetic fields measured by the Electric and Magnetic
Field Instrument Suite and Integrated Science (EMFISIS) instrument on board Van Allen Probe A shows
that the waves propagated at small angles to the geomagnetic field and oppositely to its direction, that is,
from northern to southern geographic hemisphere. The time delay between the waves detected on the
ground and on the spacecraft is about 1.3 s, with ground-based detection leading spacecraft detection. The
measured time delay is consistent with the wave travel time of quasi-parallel whistler-mode waves for a
realistic profile of the plasma density distribution along the field line. Therefore, chorus wave packets
were detected first at Kannuslehto on the ground, and then in 1.3 to 1.4 s they reached the Van Allen
Probe A on the opposite side of the magnetic equator. Taking into account the common knowledge about
near-equatorial location of chorus generation region, the only realistic scenario which satisfies the
observation facts suggests downward propagation of chorus wave packets from the generation region to
the ionosphere, partial transmission to the ground, partial reflection from the ionosphere and coming back
to the near-equatorial region where they were detected by the spacecraft. A fairly large amplitude of
chorus waves measured by the Van Allen Probe A speaks in favor of either good reflection from the
ionosphere, or additional cyclotron amplification in the equatorial region on the path from the ionosphere
to the spacecraft. The results suggest that chorus discrete elements can preserve their spectral shape
during a hop from the generation region to the ground followed by reflection from the ionosphere and
return to the near-equatorial region.
142
YOUNGER DRYAS AND RADIOCARBON DATA
Dergachev V.A., Kudryavtsev I.V.
Ioffe Institute, St. Petersburg
It is well known that data of cosmogenic isotope 14
С content in the Earth’s atmosphere reflect changes of
the Galactic Cosmic Rays (GCR) intensity. This is due to the fact that solar activity (SA) modulates the
GCR intensity during their propagation in the Heliosphere that allows us to use the radiocarbon data to
study variations of SA during the last centuries and millennia. However, the changes of terrestrial climate
distort the information about SA fixed in the radiocarbon data. In the present work we analyze the content
of radiocarbon (Δ14
C) in the Earth atmosphere in 11-10th centuries BC. This time interval contains the so-
called Younger Dryas (≈10700-9700 BC). The Younger Dryas is one of the most well known examples of
abrupt climate change. The Younger Dryas is clearly observed in paleoclimatic records from many
locations in the world. A sudden cold period after a long period of increased global temperature and
melting of glaciers took place during this interval. This cold period lasted for about one thousand years,
and about 12 thousand years ago a transition from the Last Glaciation to the interglacial Holocene has
happened. During the Younger Dryas the value of Δ14
C decreased by 6 %. Is this reduction connected
with changes in intensity of GCR or is it related to climatic changes? To answer this question the
variations of the absolute value of 14
C content in the Earth’s atmosphere, obtained on the basis of Δ14
C
and the concentration of CO2 in the atmosphere were analyzed. It was found that the major part of Δ14
C
change can be related to the variations of CO2 in the Earth’s atmosphere after its redistribution between
the atmosphere and the ocean due to the changes of global temperature. The remaining part of 14
C
variations ( 2%) in the atmosphere can be connected with alterations of the 14
С production rate due to
the changes of SA and (or) the geomagnetic field. As a result, during the Younger Dryas there was the
reduction of the 14
С production rate. As well the content of 14
С in various natural reservoirs is analyzed in
the present work.
This work was partially supported by the Russian Foundation for Basic Research (grant no. 18-02-
00583).
THEMIS AND MAIN CAMERA SYSTEM OBSERVATIONS - A CASE
STUDY
I.V. Despirak1, T.V. Kozelova
1, B.V. Kozelov
1, A.A. Liubchich
1
Polar Geophysical Institute, Apatity, Russia
One case of substorm activity on 24 December 2014 by simultaneous THEMIS satellite and ground-based
observations was considered. In the interval 16:30-20:00 UT, when the KP index was between 3 and 3+,
the complex substorm activity was observed: substorm on 16:45 UT; small substorm-like disturbance on
19:18 UT; small substorm on 19:37 UT and substorm on 19:45 UT. The active auroras were observed by
Multiscale Aurora Imaging Network (MAIN) in Apatity, the magnetic disturbances were recorded by
IMAGE network, Tixie (TIK), Amderma (AMD) and Lovozero (LOV) magnetometers. Magnetic
activation enhancement began between TIK-AMD at ~16:10 UT and then westward expands to AMD and
LOV, where Pi2 pulsations at ~16:45 UT observed. For the substorm intensifications at the interval from
~18:30 to ~19:30 UT, the projection of THD satellite orbit crossed Kola Peninsula. We made the detailed
comparative analysis of auroras and satellite observations only for first substorm at ~16:45 UT. The
temporal evolution of the auroral phenomena are interpreted as the ionospheric manifestation of the
143
process in the near-Earth magnetotail during substorm. We show that the dipolarization fronts (DF) and
associated wave intensifications in the magnetosphere were registered during the consecutive auroras
activations. The DFs were associated with enhanced energetic electron fluxes, as well as with intense
electric fields and intense wave activity. The electric field activity primarily consist of a DC electric field
variations and lower hybrid drift (LHD) waves. Electron cyclotron harmonic (ECH) waves were detected
slightly after the magnetic field reached a maximum associated with a substorm dipolarization front.
Magnetic field energy concentrated around 100 Hz were detected near DF moments.
COMPARISON OF DIFFERENT LATITUDE SUBSTORMS DURING TWO
LARGE MAGNETIC STORMS
I.V. Despirak1, N.G. Kleimenova
2, V. Guineva
3
1Polar Geophysical Institute, Apatity, Russia
2 Schmidt Institute of the Physics of the Earth RAS, Moscow, Russia
3Space Research and Technology Institute (SRTI), Stara Zagora Department, Stara Zagora, Bulgaria
The spatial-temporal development of the substorm westward electrojet has been studied during two large
geomagnetic storms: the St. Patric`s day storm (17 March 2015) and the storm on 22 June 2015. These
two storms demonstrated some similar behavior: both storms were of the two-step progression and
characterized by the very strong intensity (SYM/H<-200 nT), both storms were caused by the solar wind
Sheath impact. We have done a comparative analysis of the magnetic substorm dynamics documented
during these storms at the INTERMAGNET and IMAGE magnetometer networks. The obtained results
were compared with the OMNI data base of the solar wind and Interplanetary Magnetic Field (IMF)
parameters. The spatial-temporal dynamics of two substorms has been studied in detail: the first substorm
observed at 17:30 UT on 17.03.15 and the second one observed at 18.40 UT on 22.06.15. Both substorms
were registered as well at middle and low latitude stations (below ~50°CGLAT) as the positive magnetic
bays. The positive bay related to the first substorm was stronger than the positive bay associated with the
second one. Both considered substorms were characterized by the sharp poleward expansion of the
westward electrojet, which developed simultaneously with their slower drift to the lower latitudes. Then,
a further poleward electrojet jump reached the BJN station (~ 71° CGLAT) in the first storm
(17.03.2015), and the NAL station (75° CGLAT) in the second storm (22.03.2015). The first considered
event was observed during the main phase of the first storm and the second event – in the time of the
Storm Sudden Commencement (SSC) of the second storm. Thus, the first case demonstrated the spatial-
temporal behavior typical for a “classical” substorm, and the second case –for an “expanded” substorm.
We suggested that, probably, that is associated with different solar wind conditions favorable for the
development of different substorm types: the “classical” substorms are developed under the magnetic
cloud (MC) conditions, and the “expanded” substorms - under the Sheath region impact.
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LARGE-SCALE TYPES OF THE SOLAR WIND AND APPEARANCE OF
MAGNETIC SUBSTORMS
I.V. Despirak1, A.A. Liubchich
1, N.G. Kleimenova
2
1 Polar Geophysical Institute, Apatity, Russia
2 Schmidt Institute of the Physics of the Earth RAS, Moscow, Russia
We considered the solar wind streams types and their possible influence on the appearance of the specific
magnetic substorms. The catalog of the large-scale solar wind phenomena (ftp://ftp.iki.rssi.ru/omni/) and
OMNI data base have been used for determination of the solar wind stream types. We selected substorms
by the data of SuperMAG global magnetometers network and meridional chain of IMAGE
magnetometers. Three types of substorms have been considered: two types of the substorms observed at
the geomagnetic latitudes higher ~ 70° CGC (“polar” and “expanded” substorms) and the supersubstorms
(the particularly intense substorms with SML index < - 2500 nT). Six solar wind streams types have been
analyzed: the high speed streams from coronal holes (FAST); the interplanetary manifestations of coronal
mass ejections: the magnetic clouds (MC) or EJECTA; the regions of compressed plasma before these
streams – CIR and SHEATH; the slow solar wind (SLOW) streams. The 186 “polar”, 202 “expanded”
and 77 “supersubstorm” (SSS) events have been selected. It was found that these different substorm types
occur during different solar wind types. It was shown that supersubstorms events were associated with
SHEATH, MC, EJECTA and they almost did not observed during FAST and SLOW. The “expanded”
substorms were usually registered during FAST and compressed plasma regions (CIR, SHEATH), as well
as during EJECTA. The "polar" substorms were observed during SLOW and EJECTA that occur against
the background of a slow flow of solar wind, as well as at the end or at the beginning of FAST, when the
solar wind speed already or not yet reaches high values. Thus, the behavior of the ground-based
substorms significantly controls by the types of the solar wind streams.
COLLISIONLESS MAGNETIC RECONNECTION: 3D STRUCTURE OF JET
FRONTS IN THE PRESENCE OF A GUIDE FIELD
A. Divin1, V. Semenov
1, I. Zaytsev
1
St. Petersburg University, St. Petersburg, 198504, Russia
e-mail: [email protected]
In this study we investigate properties and substructures of reconnection jet fronts (RJFs) developing at
the interface between reconnection ejecta and pre-existing plasma sheet. An implicit PIC code is used to
perform a set of 2D and 3D numerical simulations of the initial Harris current layer with different guide
fields ranging from 0 to 2 (times the upstream magnetic field). First, at earlier stages of the evolution,
nearly two dimensional fronts are formed which push the current layer plasma away from the X-line.
Fronts accelerate and reflect particles, producing parallel ion beams and increasing parallel ion
temperature ahead of the front. Second, we simulate the three dimensional evolution of the fronts at later
stages by replicating the 2D configuration (fields and particles). For zero to low guide fields (0, 0.05,
0.45), the Lower Hybrid (LH) range instability develops at the front edge, leading to formation of
interchange “fingers” and heating of electrons parallel to the B field. Moderate guide field (~1.0)
produces wave activity at the front which however saturates at relatively low amplitude. High guide field
(~2.0 times the reconnecting component) magnetizes the front edge completely, with no wave activity
145
produced. Our simulations indicate that the LH-range waves (commonly found at dipolarization fronts in
the Earth’s magnetotail) should be suppressed and vanish if the guide field is large enough (~1.0).
ON THE SIMILARITY OF THE SERPENTINE EMISSION SPECTRA AT
GEOMAGNETIC POLES
B.V. Dovbnya1, B.I. Klain
2
1,2 Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian
Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
e-mail: [email protected], [email protected]
Simultaneous analysis of the serpentine emission (SE) spectrograms at Vostok (corrected geomagnetic
coordinates -85.41, 69.01) and Thule (corrected geomagnetic coordinates 86.78, 32.26) observatories
was realized. It is shown that the dynamics of the emission frequency modulation at some time intervals
is similar. The observed effect allows us to confirm that emission with a deep modulation of the carrier
frequency has a natural origin. We put forward this hypothesis about the nature of the observed effect in a
series of early works.
This work was supported by Russian Foundation for Basic Research 16-05-00056
STATISTICAL STUDY OF THE EFFECT OF THE SUBSTORM ACTIVITY
ON THE FORMATION OF NOISE ULF EMISSIONS IN THE FREQUENCY
RANGE (0 – 7) Hz
B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya
Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian
Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
e-mail: [email protected], [email protected], e-mail: [email protected]
A study of simultaneous observations of the mid-latitude noise ultra-low-frequency (ULF) emissions in
the frequency range 0-7 Hz and perturbations in the nighttime sector of the auroral oval was made.
Dynamic spectra of ULF emissions used for the analysis were obtained from the magnetic field
observations at the mid-latitude Borok Observatory (L = 2.8) (data from the Archive of the GO Borok
IPE RAS) and one-minute AL index data obtained from the World Data Center on Solar–Terrestrial
Physics (Moscow, Russia) (http://www.wdcb.ru/stp/geomag/geomagn_AU_AL_AE_AO_ind.html).
It is found that in the hertz range, mainly in the summer season, two types of noise ULF emissions are
observed together. One of the emissions has the form of a diffuse spots; the other emission is
characterized by the presence of resonance spectral structures (ionospheric Alfven resonances - IAR).
Noise emissions in the form of diffuse spots have an oval shape and there are no structures in them. The
fanlike spectral bands of the increasing or decreasing frequency are clearly visible in the IAR emissions.
In total, 334 cases of joint observation of diffuse spots and IAR were analyzed during the period 1985-
1988. Diffuse spots are mainly observed in the evening sector of the magnetosphere. They preceded the
appearance of IAR which are recorded predominantly near midnight. The maxima of diurnal distributions
of the spots and IAR were shifted by about 6 hours. This confirms that the time of observation of diffuse
spots is outstripped in comparison with the time of IAR observation. Simultaneous comparison of the
146
observation intervals of diffuse spots with the AL index dynamics showed that in 80% of cases diffuse
spots are formed against the background of the substorm activity development in the evening sector of the
auroral zone. In the dominant number of cases, diffuse spots develop through 60 min after the
substorms development. It is shown that the probability of diffuse spots observation depends on the AE
index magnitude characterizing the intensity of the substorm disturbances. The seasonal variation in the
duration of diffuse spots coincides with the seasonal variation of the substorms duration, the maximum
duration of which occurs in the summer season.
The obtained experimental facts allow assuming that the formation of diffuse spots is associated with the
features of the dynamics of injected protons from the tail of the magnetosphere during the substorms and
the appearance of plasmospheric plumes in the evening sector.
SOME PECULIARITIES OF THE DIURNAL, SEASONAL AND CYCLIC
VARIATIONS OF MID-LATITUDE ULF EMISSIONS WITH RESONANCE
STRUCTURE OF THE SPECTRUM
B.V.Dovbnya, B.I.Klain, N.A.Kurazhkovskaya
Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian
Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
e-mail: [email protected], [email protected], e-mail: [email protected]
The analysis of the dynamic spectra of ULF emissions in the frequency range (0 - 10) Hz
obtained from the data of long-term observations of the magnetic field at the mid-latitude Borok
Observatory (L = 2.8) is performed (data from the Archive of the GO Borok IPE RAS). In total, over
2784 days during which the emissions with a resonance structure of spectrum (ionospheric Alfven
resonances-IAR) were identified for two observation intervals (1984-1993) and (1997-2016) were
analyzed.
It was found that in 30% of cases IAR are accompanied by simultaneous observation of structured
geomagnetic pulsations Pc1 (“string-of-pearls”) and in 70% of cases IAR are recorded without Pc1
excitation. A characteristic feature of pearls is that they are observed mainly at the frequency of the first
resonant band of IAR. In this case the behavior of the frequencies of the IAR and wave packets Pc1 in
80% of the cases is qualitatively the same. We divided the initial data conditionally into two groups: 1)
IAR (1951 days of observations); 2) IAR, accompanied by pearls (833 days of observations).
It is shown that the maximum probability of the IAR observation of the two groups is dominant until
midnight (2000-2200) of MLT. The seasonal variation of the IAR of both groups is characterized by the
presence of two equinox maxima. An apparent inverse relationship between the probability of observing
IAR and solar activity has been established. The maximum of the IAR observations corresponds to a
minimum solar activity. A deviation from this pattern was observed in the 23 cycle of solar activity for
the IAR group, accompanied by pearls. In this cycle, the maximum probability of IAR observation falls
on the phase of the decline in solar activity, as well as the pulsation of Pc1. It is shown that the 11-year
variation of the IAR emissions is controlled by the dynamics of some parameters of the solar wind and
IMF. The probability of the IAR observations is maximal when the ratio of the proton density to the
density of the helium (α-particle) ions - Np/Na and the parameter (characterizing the ratio of the
thermal pressure to the magnetic pressure) reach the maximum values and when the dynamic pressure of
the solar wind - Pdyn (controlling compression of the magnetosphere) decreases.
The coincidence of dynamics of the frequencies of the first resonance band of IAR and pearls as well as
their seasonal and cyclic variation may indicate the interrelation of these oscillatory processes and the
possible common mechanism of their generation.
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THE ELECTRON ENERGY SPECTRA ON THE NIGHTSIDE (r = 6-11 Re)
DURING GEOMAGNETIC STORMS
Dubyagin S.V.1, Ganushkina N. Y.
1,2
1 – Finnish Meteorological Institute
2 – University of Michigan
The plasma sheet temperature and density empirical models are often used to compute the fluxes
for the boundary of conditions of the inner magnetosphere particle simulations. However, such
computation requires information about the particle energy spectrum. It is usually assumed that the
spectrum can be described by Maxwellian or kappa distributions. Using THEMIS measurements of the
particle flux during the geomagnetic storms, we study the spectral properties of the electron population in
the nightside transition region r=6-11 Re. It was found that the energy spectrum cannot be described by
any of standard distributions in majority of the cases. If the measured electron fluxes are compared with
those computed from the density and temperatures (estimated from measured spectrum assuming some
distribution function), the best agreement is obtained for thermal energies (1-10keV) and for kappa
distribution with k=3-4. The median relative error of the electron flux estimated in this way is ~30% for
the energies ~1-10 keV but it becomes larger than 100% for the energies 40-150keV. The two population
fit to the measured spectrum gives much better result. We discuss the possibility of building an empirical
model of density and temperature for two populations or building a model of electron fluxes for several
energies.
ELECTROMAGNETIC FIELDS OF MAGNETOSPHERIC ULF
DISTURBANCES IN CONJUGATE IONOSPHERES: CURRENT/VOLTAGE
DICHOTOMY
E.N. Fedorov 1, V.A. Pilipenko
2
1 - Institute of Physics of the Earth, Moscow ([email protected])
2 - Space Research Institute, Moscow ([email protected])
A circuit analogy for the magnetosphere-ionosphere current systems has two extremes for drivers
of ionospheric currents: the “voltage generator” (ionospheric electric fields/voltages are constant while
current varies) and the “current generator” (current is constant while the electric field varies). Here we
indicate another aspect of magnetosphere - ionosphere interaction which should be taken into account
when considering the current/voltage dichotomy. We show that non-steady field-aligned currents interact
with the ionosphere in a different way depending on a forced driving or resonant excitation. A quasi-DC
driving corresponds to a voltage generator, when the ground magnetic response is proportional to the
ionospheric Hall conductance. The excitation of resonant field line oscillations corresponds to the current
generator, when the ground magnetic response practically does not depend on the ionospheric
conductance. According to the suggested conception such phenomena as Traveling Convection Vortices
should be considered as resonant response of the magnetospheric field lines and they correspond to
current generator. Quasi-DC non-resonant disturbances such as Sudden Commencement correspond to
voltage generator. Although, there quite a few factors may obscure the determination of the
current/voltage dichotomy.
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ANALYSIS OF CHEMICAL COMPONENTS OF POLAR WINTER
ATMOSPHERE DURING RELATIVISTIC ELECTRON PRECIPITATION
Golubenko Kseniia1, Mironova Irina
1, Rozanov Eugene
2, Artamonov Anton
3
1 – St. Petersburg State University, St. Petersburg, Russia.
2 – PMOD/WRC and IAC ETHZ, Davos Dorf, Switzerland.
3 – Research Institute for Space Medicine Federal Research Clinical Center of Federal Biomedical
Agency of Russia, Moscow, Russia
In this paper we consider variability of chemical components of the polar winter atmosphere
during relativistic electron precipitation. The spectra of relativistic electron precipitation were obtained
from balloon measurements and taking into account for calculation of ionization rates. One-Dimensional
Chemical Model of the Atmosphere was used to verify the computed ionization rates and analysis of the
chemical composition of the polar winter atmosphere. The results of our analysis show the importance of
relativistic electron precipitation during perturbed conditions of the magnetosphere for changes of
concentration of chemical components of the polar winter atmosphere.
THE INFLUENCE OF FORESHOCK ORIENTATION ON THE POLAR CUSPS
OSCILLATIONS
Guglielmi A.V., Kozyreva O.V.
Institute of Physics of the Earth RAS, Moscow, Russia
e-mail: [email protected]
Ultra-low-frequency oscillations of the magnetospheric cusps are observed permanently in the near-mid
sector of auroral oval in the form of so-called IPCL. In this paper, we posed the question: do
electromagnetic waves incident on cusp from the foreshock (it is a special region of cosmic plasma
existing before the front of the magnetosphere) affect the IPCL regime? We have proposed a method of
experimental investigation, which is based on the idea of the foreshock position dependence on the
interplanetary magnetic field orientation. A hypothesis has been put forward on the existence of a specific
effect of the IPCL north-south asymmetry. We tested our hypothesis using IPCL observation data from
the Hornsund (Spitsbergen) and Davis (Antarctica) observatories. We found confirmation of the
hypothesis at a high confidence level of statistical significance. The result of our work is the following:
1. The database for statistical and synoptic studies of the effect of the interplanetary magnetic field on the
vibrational activity of magnetospheric cusps has been created.
2. The methodology is proposed for investigation the dependence of the magnetospheric cusps
oscillations on the orientation of the foreshock.
3. The hypothesis of existence of the specific north-south asymmetry of magnetospheric cusps
oscillations has been confirmed.
Our work was partially supported by the Program 28 of the Presidium of RAS, and RFBR project 16-05-
00056.
149
OBSERVATION OF THE PROTON AURORA DYNAMICS AND THE SAR
ARC OCCURRENCE AS A CONSEQUENCE OF THE INTENSE
CONVECTION AND SUBSTORM
Ievenko I.B.
Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy, Yakutsk, Russia.
It is known that the 486.1 nm line (H-beta) is emitted by atomic hydrogen as a result of precipitation of
protons with the energy of ~ 10-30 keV and their charge exchange at the altitudes of ionosphere E layer
(proton aurora). The red line of atomic oxygen (630.0 nm) in the aurora is radiated at the ionosphere F2
region altitudes as a result of precipitation of electrons with energies up to ~ 1-2 keV. The velocity of
magnetic drift of the charged particles in the magnetosphere is proportional to their energy. The energy of
particles does not influence to the electric drift velocity.
In this work, the dynamics of electron and proton aurorae in the evening MLT sector at the Yakutsk
meridian (130ºE; 200ºE, geom.) during the magnetic storm on January 7, 2015 using the all-sky imager
(ASI) is analyzed. The angular westward motion velocity of the auroral structures in the 630.0 and 486.1
nm emissions along the magnetic latitude of 58°N at a high value of electric field of the solar wind –
VX×BZ = 9 mV / m (dawn-dusk) has been defined. On the basis of this parameter the value of radial
component of the convection electric field and the precipitating protons energy have been estimated.
Next, ASI data show an intensification of aurorae in the 630.0 and 486.1 nm emissions in the range of
geomagnetic latitudes of 56-61°N and occurrence of the stable auroral red (SAR) arc at latitudes of 49-
52°N in ~20 minutes after the onset of an intense substorm expansion. Measurements aboard the Van
Allen Probes A satellite show a sharp increase of fluxes of the energetic Н+, О
+ ions (injection boundary)
at the L ~ 2.6-3.0 at the same time near the Yakutsk meridian. The satellite registers the overlap of
energetic ion fluxes with a plasmapause in this L interval. This region is mapped by the SAR arc at lower
latitudes (L ~ 2.2-2.6) pointing to the nondipole configuration of the geomagnetic field in the inner
magnetosphere at the current values of SYM-H ~ -120 nT and ASY-H ~ 150 nT. The research is partial
supported by RFBR grants No 18-45-140037 р_а
EASTWARD PROPAGATION OF THE PC1 WAVES ALONG THE
PLASMAPAUSE ACCORDING TO OBSERVATION OF THE DYNAMICS OF
PROTON AURORA AND SAR ARC
Ievenko I.B., Parnikov S.G., Baishev D.G.
Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy, Yakutsk, Russia.
The stable auroral red (SAR) arcs are the consequence of interaction of the plasmapause with energetic
ions of the ring current. The geomagnetic pulsations Pc1 are registered on the Earth as a consequence of
generation of electromagnetic ion cyclotron (EMIC) waves in the equatorial plane of the magnetosphere.
The EMIC instability causes scattering of ring current protons into the loss cone. Precipitation of
energetic protons and their charge exchange at the heights of the ionosphere E layer can be observed as a
proton aurora in the H-beta line of atomic hydrogen. In this work the dynamics of the SAR arc, proton
aurora and Pc1 waves in the MLT evening sector at the Yakutsk meridian (130ºE; 200ºE, geom.) using
150
the all-sky imager (ASI) and an induction magnetometer during the growth and expansion of intense
substorms on December 31, 2015 is analyzed.
During the enhanced magnetospheric convection due to the southward IMF Bz turning ASI observes an
equatorward motion of the diffuse aurora (DA) boundary in the 557.7 and 630.0 nm emissions and H-beta
(486.1 nm) band from the northern horizon of observation station. At the same time, the weak SAR arc
appears equatorward of DA. In 10 minutes after the expansion onset of intense substorm in the midnight
MLT sector ASI registers the SAR arc intensity growth from the western horizon toward the east with an
angular velocity of ~ 4 deg/ min. As a result, along the arc a few intensity maxima are formed. At the
same time, the narrow arc in the H-beta emission with similar dynamics appears northward of the SAR
arc at a distance of ~ 0.6º.
The induction magnetometer detects a sharp increase of Pc1 pulsation amplitude at frequencies of 0.5–0.7
Hz during the arrival of end of the arc in the H-beta emission to the zenith of observation station. The Pc1
pulsations and the dynamic proton arc are registered within ~ 30 minutes. The SAR arc is registered by
ASI until about 1400 UT. We connect the observed phenomena in the SAR arc and proton aurora with the
eastward propagation of the excitation region of EMIC waves along the plasmapause in the evening MLT
sector. The research is partial supported by RFBR grants No 18-45-140037 р_а
AN APPROACH TO REGIONAL THREE-DIMENSIONAL MODELLING OF
GROUND ELECTROMAGNETIC FIELD VARIATIONS DURING SPACE
WEATHER EVENTS USING RESULTS OF MAGNETOHYDRODYNAMIC
MODELLING OF THE EARTH’S MAGNETOSPHERE AND IONOSPHERE
Elena Ivannikova1,2
, Mikhail Kruglyakov1,3
, Alexey Kuvshinov1, Lutz Rastätter
4, Antti
Pulkkinen4
1Institute of Geophysics, ETH Zurich, Zurich, Switzerland
2Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
3Geoelectromagnetic Research Centre, Schmidt Institute of Physics of the Earth, Russian Academy of
Sciences, Troitsk, Russia
4NASA, Goddard Space Flight Center, Greenbelt, Maryland, USA
In order to assess the hazard to ground-based technological systems from space weather we developed an
approach to regional three-dimensional (3-D) modelling of ground electromagnetic (EM) field variations
during space weather events using results of magnetohydrodynamic (MHD) modelling of the Earth’s
magnetosphere and ionosphere. The approach involves four main steps. First, we run a global MHD
model of the near-Earth space for geomagnetic disturbance of interest. Then, using results of MHD
modelling, we compute the spatio-temporal distribution of the external magnetic field for this event on a
regular grid at the surface of the Earth. Third, the external field is converted into equivalent current
(source of excitation equivalent to 3-D current system), and, finally, for a given source and a given 3-D
conductivity model of the Earth the spatio-temporal distribution of the ground EM field is computed in
the region of interest. Using this approach and the British Isles as a test region, we perform 3-D modelling
of the ground EM field for the Halloween geomagnetic storm in October 2003 and discuss modelling
results.
151
BY IMF AND CLOUD RADIATIVE PROPERTIES AFFECT TO THE POLAR
TROPOSPHERIC PRESSURE THROUGH THE IONOSPHERIC POTENTIAL
IMPACT TO GEC
Arseniy Karagodin 1, Mervyn P. Freeman
2, Mai Mai Lam
2, Eugene Rozanov
3, Irina
Mironova1
1 - St. Petersburg State University, St. Petersburg, Russia
2 - British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
3 - Physikalisch-Meteorologisches Observatorium World Radiation Center, Davos, Switzerland
Given investigation is devoted to evaluate the ground-level pressure response upon the variation of By-
component of interplanetary magnetic field (IMF) and changing of the cloud radiative properties that
have been examined exploiting chemical-climate model SOCOL v.2. The model was designed for study
of different impacts to the climate change. First part of this study is basing on the hypothesis that IMF By
is responsible for variations of meteorological parameters in low atmosphere through the solar wind
induced variations of the polar cup ionosheric potential. These disturbances are propagated up to lower
layers of atmosphere through global electric circuit (GEC). Connection of ionospheric potential with low
atmosphere is maintained by downward current density Jz as part of global electric circuit and cloud
microphysical process called autoconversion (ACV) rates that linked with variations of Jz see Harrison et
al. [2015]. Second part of this work is devoted to investigation from another side the problem highlighted
above. Harrison et al. [2015] mentions that increase of ACV rate is following from growing of the droplet
fusion rate efficiency. Lubin et al. [1998] highlighted that affect to tropospheric pressure anomalies
happens through the changing of the cloud optical properties under the region of polar cup IP. In our
model simulations the effective radius for ice and water droplets was set according to Lubin et al. [1998]
as 40 m and 10 m correspondingly. A few experiments were carried out for January condition in
attempt to distinguish and accept this approach as plausible for establishing connection between
ionospheric potential variation and pressure through GEC as well as impact of this effect to the local and
global climate change.
Reference
Harrison, R. G., K. A. Nicoll and M. H. P. Ambaum (2015), On the microphysical effects of observed
cloud edge charging, Q. J. R. Meteorol. Soc. (2015) DOI:10.1002/qj.2554.
Lubin D., Chen B., Bromwich D. H. ‚ Somerville Richard C. J., Lee Wan-Ho and Hines Keith M. (1998),
The Impact of Antarctic Cloud Radiative Properties on a GCM Climate Simulation, American
Meteorological Society (1998).
152
CHANGES IN THE POSITION OF THE AURORAL OVAL UNDER
CONDITIONS OF DISPLACEMENT OF THE EARTH'S MAGNETIC POLE
Kopytenko Yu.A.1, Chernous S.A.
2 Petrova A.A.
1, Filatov M.V.
2 Petrishchev M.S.
1
1 - St. Petersburg branch of IZMIRAN (SPbF IZMIRAN), St. Petersburg, Russia
2 - PGI RAS, Apatity, Russia
The aura of auroras is in fact a natural coordinate system to which the events of cosmic geophysics in the
ionosphere and magnetosphere are tied theoretically and practically. The oval was built according to the
International Geophysical Year data more than 50 years ago and is tied to the magnetic pole of the Earth,
which has shifted more than 1000 km during this time. It should be expected that the configuration and
position of the auroral oval could also be changed. The purpose of this study is to calculate and direct
experimental studies of the position of the ovals of the aurora at different times of the day with different
perturbations of the Earth's magnetic field in the present conditions of the position of the Earth's magnetic
pole. The report assesses the accuracy of measurements of the auroral position relative to the magnetic
pole at the current time by analyzing direct optical measurements at the stations of the Polar Geophysical
Institute RAS (Lovozero, Barentsburg, Apatity) and the network of stations in Northern Scandinavia
(Sodankyla, Kiruna), and from optical measurements from space. Precise data and a three-dimensional
component model of the Earth's magnetic field SPbF IZMIRAN will be used to achieve the goal, taking
into account the contribution of magnetic anomalies of the lithosphere components in the altitude range
from 80 to about 400 km, obtained from aeromagnetic, hydromagnetic and aerospace surveys.
ON APPLICATION OF ASYMMETRIC KAN-LIKE EXACT EQUILIBRIA TO
THE EARTH MAGNETOTAIL MODELING
Daniil B. Korovinskiy1, 2 Darya I. Kubyshkina
1, 3 Vladimir S. Semenov
2, 4 Marina V.
Kubyshkina2, 5 Nikolai V. Erkaev
2,3,4, 6 Ivan B. Ivanov
5, 7 Stefan A. Kiehas
1
1 – Space Research Institute, Austrian Academy of Sciences, 8042 Graz, Austria.
2 – The Earth Physics Department, Saint Petersburg State University, 198504 St. Petersburg, Russia.
3 – Institute of Computational Modelling, FRC "Krasnoyarsk Science Center" SBRAS, 660036
Krasnoyarsk, Russia.
4 – The Applied Mechanics Department, Siberian Federal University, 660041 Krasnoyarsk, Russia.
5 – Theoretical Physics Division, Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia.
A specific class of solutions of the Vlasov-Maxwell equations, developed by means of generalization of
the well-known Harris-Fadeev-Kan-Manankova family of exact two-dimensional equilibria, is examined
and utilized for the Earth’s magnetotail modeling. The presented model is developed to reproduce the
current sheet bending and shifting in the vertical plane, arising from the Earth dipole tilting and the solar
wind nonradial propagation. It is shown that for any level of magnetospheric activity the model
parameters may be adjusted to fit averaged magnetotail configurations, rendered by the empirical
Tsyganenko model, in terms of the magnetic flux tube volume. The best match of the essential model
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parameters is found for single-peaked current sheets with medium values of number density, proton
temperature and drift velocity.
Then the problem of MHD stability of bent magnetotail current sheets is considered by means of 2.5-
dimensional numerical simulations. The study is focused on the cross-tail transversal mode, modeling the
magnetotail flapping motions. It is found that in a planar Kan-like current sheet oscillating and slowly
growing unstable flapping modes are coexisting, so that for low levels of bending current sheet is
essentially stable on the substorm time scale. As the degree of bending is increased, the growth rate
increases and oscillating mode vanishes, hence the typical time scale drops to several minutes. It is also
demonstrated that contrary to the usual ballooning modes, this instability is not related to
buoyancy/entropy considerations, but is instead controlled by the cross-sheet distribution of the total
pressure. The results show qualitative agreement with the so-called double-gradient model.
THE DRIFT-COMPRESSION MODES IN THE MAGNETOSPHERIC PLASMA
Kostarev D.V.1, Mager P.N.
1, Klimushkin D.Yu.
1
1 - Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia
The theory of drift-compression modes with azimuthal wavenumbers m>>1 is elaborated in gyrokinetic
framework. The theory takes into account the bounce motion of energetic particle and the drift wave-
particle resonance. The integral equation for structure of these modes is obtained analytically and solved
numerically. For the existence of these modes the finite plasma pressure and plasma inhomogeneity
transverse the magnetic shells are sufficient. It was found that these oscillations are narrowly localized
near the geomagnetic equator and are symmetric with respect to it. They can propagate either to the west,
while resonantly interacting with energetic protons, or to the east, interacting with energetic electrons.
These modes can be generated by gradient instability when protons temperature increases with distance
from the Earth, and by the “bump-on-tail” instability. The drift-compressional modes can provide a
natural interpretation for the compressional storm-time Pc5 waves with frequencies much lower than the
Alfven frequency on the same magnetic shells.
This study was supported by the Russian Science Foundation under grant 18-17-00021.
VIRTUAL MAGNETOGRAMS – NEW TOOL FOR THE STUDY OF SOLAR
WIND-MAGNETOSPHERE COUPLING
Kozyreva O.V.1, Pilipenko V.A.
2, Soloviev A.A.
2
1 – Institute of Physics of the Earth, Moscow
2 – Geophysical Center, Moscow
Magnetic disturbances on the ground, being the images of processes of solar-wind/magnetosphere
interaction, can be monitored by comparing time-series of magnetic records on the ground with the space
weather parameters. However, a serious drawback of the analysis of ground-based magnetograms is the
inevitable variation of the magnetic response due to continual changes of the station location. An ideal,
but impossible, solution of this difficulty, that will help to discriminate temporal and spatial variations,
would be the deployment of a “stationary” observatory with a fixed position in the solar-magnetospheric
154
coordinate system. However, the desired result can be obtained with the proposed technique of “virtual
magnetograms” (VM). This technique has been implemented for key magnetospheric domains (midnight
auroral and dayside cusp regions) as an additional tool for monitoring the response of the geomagnetic
field to the solar wind and interplanetary magnetic field (IMF) forcing. VM for a fixed reference system
is reconstructed by 2D spatial gridding of 1-min magnetic data from world-wide distributed magnetic
stations. The VMs have been produced for the period since 1996 up to nowadays. A wide range of space
physics studies, such as substorm triggering, solar wind-ionosphere interaction, sawtooth oscillations,
ionospheric convection response to IMF variations, etc. will benefit from the introduction of the VMs.
The database of calculated VMs for the dayside cusp and midnight auroral regions, as well as
simultaneous interplanetary parameters (solar wind electric field) and geomagnetic indices (AE-index) are
available via the specially designed site http://vm.gcras.ru/ for all interested researchers for testing and
validation.
INTERMITTENCY STATISTICS OF HIGH-LATITUDE GEOMAGNETIC
PULSATIONS PI2
N.A.Kurazhkovskaya, B.I.Klain, I.A.Yelagina
Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian
Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
e-mail: [email protected]; [email protected], [email protected]
In this work, we present the results of a comparative analysis of the intermittency conformities of two Pi2
geomagnetic pulsations groups: 1) isolated bursts (970 events) and 2) burst series (1239 events). For the
study we used the data of the magnetic field observations from the Molodezhnaya Antarctic observatory
(corrected geomagnetic coordinates - 66.7, 76.0) during the period of 1981-1992 (data from the archive
of the GO BOROK IPE RAS). It has been shown that the cumulative distribution functions of the
amplitudes of both isolated Pi2 bursts and burst series are well approximated by power functions. As a
characteristic of intermittency, we considered index α, which reflects the slope of the cumulative
distribution function of the amplitudes of the Pi2 bursts.
The diurnal and seasonal variations of the parameter α of both groups of Pi2 pulsations were investigated.
It was found that the diurnal dynamics of α isolated Pi2 bursts is characterized by a maximum (α = 6.41)
in the post-midnight hours (0100-0200 MLT). In contrast to Pi2 isolated bursts, a maximum (α = 5.59) of
the diurnal variation of the parameter α of the Pi2 burst series is observed in the evening sector (2000-
2100 MLT). The seasonal dynamics of the index α of Pi2 isolated pulsations is characterized by the
presence of two maxima: in the season of spring (α = 3.57) and fall equinoxes (α = 3.27). In the seasonal
variation of the index α of Pi2 bursts series two maxima are also distinguished, but in contrast to isolated
bursts in the season of summer (α = 8.06) and winter solstices (α = 8.03). Thus, the behavior of the
parameter α for the two Pi2 bursts groups varies significantly depending on the MLT and season.
The obtained results indicate that high-latitude bursts of both Pi2 pulsations groups are generated in a
highly turbulent medium (the value of α is significantly > 1). This allows us qualitatively to estimate the
degree of the plasma turbulence of the magnetosphere tail during their excitation. The burst series of Pi2
pulsations are generated in a more turbulent medium in the evening time than at other time intervals. At
the same time, the degree of plasma turbulence is relatively high after midnight during the excitation of
isolated Pi2 bursts. Depending on the season the level of turbulence of the magnetosphere tail is higher in
the equinox and solstice during the excitation of isolated bursts and a series of bursts of pulsations Pi2,
respectively. It is assumed that the differences in the regularities of the intermittency of the two Pi2 bursts
groups are due to peculiarities of the substorms behavior.
155
EFFECT OF THE SOLAR WIND AND IMF PARAMETERS ON
POLARIZATION CHARACTERISTICS OF HIGH-LATITUDE
GEOMAGNETIC IMPULSES (MIES)
N.A.Kurazhkovskaya, B.I.Klain
Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth, Russian
Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
e-mail: [email protected]; [email protected]
The results of the study of polarization characteristics (polarization type, ellipticity - ε, inclination angle
of the main axis of the polarization ellipse - τ) of the high-latitude magnetic impulse events (MIEs) and
the effect of interplanetary medium parameters on them are presented. We used the observations of a
magnetic field with a minute resolution at the Antarctic observatory Mirny (corrected geomagnetic
coordinates -76.93, 122.92) [http://www.wdcb.ru/stp/data/geo_min.val/] and one-minute data of the
solar wind and interplanetary magnetic field (IMF) parameters [http://omniweb.gsfc.nasa.gov/ow.html]
for the period 1989-1991, 1995-2003.
We divided all analyzed impulses into two groups according to the type of polarization: 1) right-polarized
impulses (R - type); and 2) left-handed impulses (L - type). It is established that R-type MIEs occur when
the IMF vector is close to the radial direction, and L - type MIEs occur when a direction perpendicular to
the Sun - Earth line. It has been shown that near the moment of the onset both types impulses the
orientation of the IMF Bz - component changes from the northern direction to the southern direction. In
this case, the direction of rotation of the IMF vector in the XY plane of the solar - ecliptic coordinate
system coincides with the direction of rotation of the main axis of the polarization ellipse of impulses
recorded on the Earth’s surface. The IMF vector rotates clockwise and counterclockwise in the ecliptic
plane in the case of the R and L type MIEs observation, respectively.
A reverse dependence of the τ angle of the R - type impulses and ε of the L - type impulses on the Bz -
component value was found. Also, the behavior of the polarization characteristics of impulses depends
essentially on the angle θxB value, where θxB = arccos (Bx/B). The ellipticity of the R-type impulses
reaches its maximum values at θxB ~ 45-60 and θxB ~ 135-150. The ellipticity of the L-type impulses is
minimal at the same ranges of angle θxB. The value of the τ angle of the R-type impulses is maximal for
the direction of the IMF vector perpendicular to the Sun-Earth line (θxB ~ 90-105), and L-type impulses
for θxB ~ 60-75.
It is assumed that under conditions of a quiet or moderately perturbed magnetosphere a trigger of
geomagnetic impulses of two types is the weak short-term variations of the IMF Bz - component, whose
source is the solar wind nonuniformities with the arc-shaped configuration of the IMF hodograph curve in
the ecliptic plane that determine the type of polarization of the impulses.
CONSTRAINING THE EARLY EVOLUTION OF VENUS AND EARTH BY
REPRODUCING ELEMNTAL RATIOS
Lammer H.
Austrian Academy of Sciences, Space Research Institute, Schmiedlstr. 6, 8043 Graz, Austria
e-mail: [email protected]
Compositional variations between chondrites, the solar nebula, and the chemical abundances of the
terrestrial planets provide evidence that elemental (K/U, etc.) and isotopic fractionation of atmospheric
156
noble gases should have taken place early in the history of their evolution. During the disk-embedded
phase, early in the evolutionary history of the solar system, protoplanetary cores of Venus and Earth are
believed to accumulate hydrogen gas and to form thin planetary H2-envelopes. According to 182
Hf-182
W
isotope studies, the protoplanets of both terrestrial planets should have accumulated about 0.45-0.75
Earth-masses, respectively, until the circumstellar disk evaporated. Afterwards, related to the young Sun,
EUV-driven hydrodynamic escape started to slowly evaporate the accumulated H2-envelopes of both
proto-planets. Additionally, constant bombardment of impacting material, delivered further material to
growing proto-Earth and -Venus. Lighter elements, such as potassium (K) compared to the heavier
uranium (U), as well as atmospheric noble gas isotopes, as for example 36
Ar compared to 38
Ar, or 20
Ne
compared to 22
Ne can escape easier from the accreting proto-Earth and proto-Venus due to hydrogen-drag
from a nebula-captured hydrogen-envelope, compared to a magma ocean related outgassed steam
atmosphere. Heavier elements and isotopes cannot be dragged away that easily. Simulations of the
hydrodynamic escape of the accumulated hydrogen envelope around proto-Earth and proto-Venus show
that this effect can explain initial compositional variations between the terrestrial planets and the solar
nebula. It is also shown that in the case of the Earth delivery of chondritic material is necessary to
reproduce the observed fractionations. These model results are also supporting the Grant-Tack scenario,
and are in agreement with 182
Hf-182W chronometric fast accretion scenarios of the Earth with a late Moon-
forming giant impact.
KELVIN-HELMHOLTZ INSTABILITY OF THE LOW-LATITUDE
BOUNDARY LAYER OF THE GEOMAGNETIC TAIL
Leonovich A.S.1, Kozlov D.A.
1
1 – ISTP SB RAS, Irkutsk
The low-latitude boundary layer (LLBL) stability problem in the geomagnetic tail is studied. To describe
the boundary layer between plasma sheet and magnetosheath, we use a cylindrical model of the tail
enwrapped by a helical solar wind flow. Unlike plane-stratified medium models, the cylindrical model
allows us to take into account the finite cross-section of the tail and the curvature of closed field lines in
the LLBL region. The problem is investigated both in the tangential discontinuity (TD) approximation
and for a finite thickness transition layer. It is shown that there are three types of unstable MHD modes
that can develop in the region: 1) surface modes on the LLBL, 2) radiative modes (waves radiated into the
solar wind), and 3) the eigen-modes of the tail waveguide.
The dispersion equation solution in the TD approximation shows that symmetric modes (m = 0) are
unstable for any low-speed flows, while asymmetric modes (m > 0) become stable when solar wind speed
is lower than a certain threshold. All modes become stable when solar wind flow speed are higher than a
upper threshold, so the surface waves can be generated in the low- to medium-speed solar wind (200-400
km/s). The non-zero azimuthal component of the flow velocity (described by the helicity index, the ratio
of azimuthal to axial velocity) significantly affects both the Mach number dependence of the surface
wave growth rate and the velocity threshold values. The higher the helicity index, the lower the
magnitude of the upper threshold. The surface modes have the largest growth rate.
When taking into account the finite thickness of the shear layer, the dependence of the growth rate on the
flow speed and tangential wavelength demonstrates a local maximum at the wavelengths of the order of
the LLBL thickness and at the Mach number M ≈ 0.5. As the Mach number increases, the surface waves
gradually transform into radiative modes. The radiative modes remain unstable even when their
wavelength is much less than the shear layer thickness.
The plot of γ vs f (where γ = Im(ω), and f = Re(ω)/2π) shows that the waves generated by low- and
medium-speed solar wind flows (v0 = 200, 400 km/s) have a maximum at frequency f ≈ 0.02 Hz, and the
range of unstable oscillations corresponds to the Pc3–Pc6 range.
157
In the high-speed flows (800 km/s) with a small helicity index, the maximum growth rate of unstable
oscillations is at frequency f ≈ 0.01 Hz. The maximum frequency above which the oscillations become
stable is f ≈ 0.02 Hz, and the unstable oscillations occupy the Pc4–Pc6 range. These oscillations are
radiative modes with much smaller growth rates than surface waves generated in low- and medium-speed
solar wind flows. In solar wind flows with high helicity index unstable radiative modes have a higher
growth rate, and their frequency range occupies the entire Pc1-Pc6 range.
IONOSPHERIC DISTURBANCE CAUSED BY RADIATION OF
CHELYABINSK BOLIDE FLIGHT
Losseva T.V.1, Golub’ A.P.
2, Lyakhov A.N.
1, Kosarev I.B.
1
1 - Institute of Geosphere Dynamics RAS, Moscow, Russia
2 - Space Research Institute RAS, Moscow, Russia
A physical model of the action of radiation from a bolide on Earth’s lower ionosphere at the stage
of its flight is presented. The calculations within this model are applied to the Chelyabinsk bolide case on
February 15, 2013. Thermal radiation fluxes impact on the lower ionosphere accompanying the passage
of the Chelyabinsk bolide is studied by means of numerical solution within the radiation gas dynamics
model from the 60 km altitude, where bolide entries into the dense layers of the atmosphere and its
evaporation begins, to the height of 30 km, where a body separates to large fragments with further
disruption. This model includes all necessary physical processes: the deceleration and ablation of the
meteoroid in the atmosphere within the framework of physical theory of meteors; radiation gas dynamical
processes in the vaporized meteor substance and ambient air as well; the far field thermal radiation
transfer in the atmosphere; the excitation of the lower ionosphere described, in turn, by 22 components
plasma-chemical model, including the set of minor short-lived constituents. Numerical modeling was
performed using tables of thermodynamic and optical characteristics of the air and meteoroid material
vapor (LL-Chondrite), calculated based on a mixture of 16 elements: Fe-O-Mg-Si-C-N-H-S-Al-Ca-Na -
K-Ti-Cr-Mn-Ni. Verification of the model was evaluated on the luminosity curves in visible and near
infrared ranges obtained at different points of ground-based observations and satellite measurements, as
well as with the existing integral optical data. The results show that the radiation of the Chelyabinsk
bolide in the first 10 seconds of his flight from 60 to 30 km altitude caused the formation in the Earth's
ionosphere (80-120 km) of wide ionized region with dimensions of the order of 400 km and the electron
density within this region increased to the plasma frequency of 3.5 MHz. This quantitatively coincides
with EKB SuperDARN radar system data. The total electron content (TEC) perturbation of 0.1 TECU is
consistent with observations at the GPS registration system stations in the Ural region. During this time,
meteoroid energy radiation losses are as large as approximately 40% of its total energy (where 15% are in
the photon energies range of 1.1-3.1 eV). The numerical models of geophysical effects caused by
meteoroid flights in Earth’s upper and middle atmosphere would include radiation effects.
158
SIMULTANEOUS OBSERVATIONS OF A COMPRESSIONAL Pc5 WAVE
BY EKB RADAR IN THE IONOSPHERE AND BY VAN ALLEN PROBES IN
THE MAGNETOSPHERE
Mager O.V., Chelpanov M.A., Mager P.N., Klimushkin D.Yu., Berngardt O.I.
Institute of Solar-Terrestrial Physics SB RAS
The work presents an analysis of a Pc5 wave registered on November 22, 2014 simultaneously by
Ekaterinburg decameter coherent radar (EKB radar) in the night ionosphere and by Van Allen Probes in
the conjugate region of the magnetosphere near the geomagnetic equator between 5.5 and 5.9 L-shells.
The wave had frequency about 1.8 mHz and was observed after an increase in geomagnetic activity, in
the recovery phase of a substorm. Probably, the observed wave is a drift-compressional mode: its
frequency was much lower than the estimated lowest Alfvén frequency; the wave had a predominant
longitudinal magnetic component in antiphase to the observed plasma pressure oscillations, and was
accompanied by an increase in the flux of energetic protons. Besides, the direction of wave propagation
coincided with the direction of the magnetic drift of the energetic protons: the azimuthal wave number m
calculated on the basis of radar and satellite data was about -10. And indeed, a modulation of proton
fluxes with energies 81.6 and 99.4 keV at the wave frequency was found. The magnetic drift velocity of
protons with these energies is close to the phase velocity of the wave. Therefore, it is possible that the
wave was generated due to the resonant wave-particle interaction (drift instability).
ELEMENTS OF FORECASTING OF SPACE WEATHER AND IONOSPHERIC
PARAMETERS
Maltseva O.A.1, Bezvytnyj S.A.2, Morozov B.E.2, Shilov D.I.2, Shmelev J.A.2
Institute for Physics ,SFU, Rostov-on-Don, Russia
Saint-Petersburg State University of Aerospace Instrumentation
Corresponding author e-mail: [email protected]
The forecast of space weather means prediction of the parameters of the solar wind, the interplanetary
magnetic field, Kp, Dst and others indices and is currently reliable enough and is provided on several
sites. In this connection, it is possible to predict the behavior of ionospheric parameters, in particular, the
total electron content TEC during disturbed conditions. For this, it is necessary to know the functional
dependence of the deviations δTEC of the instantaneous values of TEC from the medians. Authors of the
paper (Stankov, Jakowski, Acta Geod. Geoph. Hung., 2006, 41(1), pp. 1–15) demonstrated the possibility
of predicting δTEC using a polynomial dependence on Kp of degree n = 3. In the present work, for all the
disturbances of 2013 (17 cases were identified), the polynomial dependences of δTEC on the Kp and Dst
indices were calculated and the reliability of the R^2 approximation for various points of the globe was
estimated. The preliminary results are as follows. 1. The degree and the best correlation index depend on
the latitude (for high-latitude stations the greatest correlation is observed with the Kp index, for middle-
and low-latitude stations the correlation with Dst may predominate.) 2. The degree and best correlation
index depend on the season (the greatest correlation is observed in the winter months for high-latitude
stations and in summer for low-latitude stations.) 3. The degree of n = 3 is insufficient for approximation,
often the degree of reliability R^2 for n=4-6 exceeds the reliability for n= 3. 4. The degree of reliability
can exceed a level of 0.5, indicating both a strong connection and the possibility of forecasting.
159
This work was supported by grant 18-05-00343 from Russian Foundation for Basic Research.
MODELING AND ANALYSIS OF IONOSPHERIC CRITICAL FREQUENCY
DATA ON THE BASIS OF A MULTICOMPONENT MODEL
Mandrikova O.V., Fetisova N.V., Polozov Yu.A.
Institute of Cosmophysical Research and Radio Wave Propagation (IKIR FEB RAS)
The paper is aimed at developing the methods for the analysis of ionospheric data and studying the
processes in the ionosphere during disturbed periods. The subject of the study is ionospheric anomalies
(ionospheric storms) that occur during increased solar activity (ex. CME) and magnetic storms. They
often occur in the equatorial and auroral zones, but can also be observed in the mid-latitudes [1]. The
accuracy of the current methods for analysis of ionospheric data (median method, IRI model, and etc.)
much depends on the presence of qualitative input parameters (indices of solar and geomagnetic activity,
solar radiation spectra and etc.). At present, the problem of the operational analysis of recorded
ionospheric data and the timely detection of ionospheric anomalies is the most urgent.
A multicomponent model (MCM) of ionospheric parameters, first suggested in the paper [2], is presented
in this work. The model allows to describe regular and anomalous changes of ionospheric parameters and
is implemented numerically (http://aurorasa.ikir.ru:8580). MCM identification is based on the application
of various schemes of the wavelet decompositions and the classical autoregressive models (ARIMA). The
computational algorithms, developed by MCM, are adapted for real-time mode. They allow to
operationally detect ionospheric anomalies and to estimate their parameters.
Modeling and analysis of the foF2 ionospheric critical frequency data at stations Paratunka (IKIR FEB
RAS, Kamchatka) and Wakkanai (Japan) were performed by the MCM. A comparison of the MCM with
the median method and IRI-2012 was performed. The obtained results showed the efficiency of the
proposed model and the possibility of its use for the operational detection of anomalous changes in the
ionosphere, preceding and accompanying magnetic storms.
The paper was supported by RSF Grant No. 14-11-00194. The authors are grateful to the organizations
recording the data which were applied.
Danilov A.D. Ionospheric F-region response to geomagnetic disturbances // Advances in Space Research.
2013. Vol. 52. No. 3. pp. 343–366.
Mandrikova O.V., Fetisova N.V., Polozov Y.A., Solovev I.S., Kupriyanov M.S. Method for modeling of
the components of ionospheric parameter time variations and detection of anomalies in the ionosphere
coupling of the high and mid latitude ionosphere and its relation to geospace dynamics // Earth, Planets
and Space. 2015. Vol. 67. No 1. pp. 131-146. DOI: 10.1186/s40623-015-0301-4
160
ANALYSIS OF NEUTRON MONITORS DATA DURING THE PERIODS OF
HELIOSPHERIC DISTURBANCES
Mandrikova O.V., Zalyaev T.L., Mandrikova B.S.
Institute of Cosmophysical Researches and Radio Wave Propagation FEB RAS
email: [email protected]
Introduction. The work is devoted to the development of methods for the analysis of variations of galactic
cosmic rays (GCR) (according to the world network of neutron monitors) and the sporadic effects. The
study of GCR data is important for fundamental research in the field of solar-terrestrial physics, as well as
for applied research in space weather prediction problems [1]. Existing traditional methods of analyzing
GCR data (spectral methods, smoothing, etc.) are not sufficiently effective [2]. Modern methods and
approaches (ring station method, global survey method [3]) are effective, but require laborious
calculations and their automation is very difficult [4]. At present, the urgent task is to quickly analyze the
recorded GCR data and timely detect sporadic effects that have a negative impact on modern space
vehicles and human health.
Methods. In the paper, the authors presented a generalized model of cosmic-ray data describing recurrent
and sporadic variations. A method for identifying a model based on a combination of a neural network
apparatus and a wavelet transform is proposed. The application of the model makes it possible to
efficiently isolate recurrent components in the dynamics of cosmic rays and to identify sporadic features.
Based on neural networks of vector quantization, authors developed a method for analyzing data from
neutron monitors, which makes it possible to estimate the state of the GCR flux in automatic mode. The
computational algorithms implementing the method classify the data into three classes: "quiet class",
which determines the recurrent course of the GCR; "Weakly disturbed class" - defines sporadic effects of
small amplitude and "disturbed class" - determines sporadic effects of large amplitude.
Experiments. Based on the developed methods, the authors studied the dynamics of GCR during periods
of strong and moderate magnetic storms for 2015-2016. (the data of the neutron monitors of Kingston and
Apatity (www.nmdb.eu) were analyzed). Periods of occurrence of sporadic variations in GCR are
identified; their intensity, duration and moments of occurrence are evaluated. On the eve of most of the
analyzed magnetic storms, anomalous changes in the dynamics of GCR observed during the periods of
growth of the velocity of the solar wind and the amplitudes of the interplanetary magnetic field were
allocated.
Conclusions. The efficiency of proposed methods is experimentally confirmed, the method of their
implementation in automatic mode is proposed. Further authors plan to carry out approbation of the
developed methods on more representative statistics with the expansion of the number of analyzed data
recording stations.
The authors are grateful to the Russian Science Foundation for the financial support of the study (Project
No. 14-11-00194-P) and are grateful to the organizations that are registering the data that was used in the
work.
References
Belov, A. V, Dorman, L.I., Eroshenko, E.A., Iucci, N., Villoresi, G., Yanke, V.G., 1995. Search for
Predictors of Forbush Decreases, in: Proceedings of 24Th International Cosmic Ray Conference. pp. 888–
891
Vipindas V, Gopinath S, Girish TE (2016) Periodicity analysis of galactic cosmic rays using Fourier,
Hilbert, and higher-order spectral methods. Astrophys Space Sci 361:. doi: 10.1007/s10509-016-2719-y
Nagashima K, Sakakibara S, Murakami K, Morishita I (1989) Response and yield functions of neutron
monitor, galactic cosmic-ray spectrum and its solar modulation, derived from all the available world-wide
surveys. Nuovo Cim C 12:173–209. doi: 10.1007/BF02523790
161
Grigoryev VG, Starodubtsev SA (2015) Global survey method in real time and space weather forecasting.
Bull Russ Acad Sci Phys 79:649–653. doi: 10.3103/S1062873815050226
IN SEARCH OF DISTURBANCES OF THE UPPER IONOSPHERE AND
GEOMAGNETIC FIELD ABOVE HURRICANES AS OBSERVED BY
SWARM SATELLITES
1 Martines-Bedenko V.A.1, 2 Pilipenko V.A.1,2, 3 Zakharov V.I.3
1 - Institute of Physics of the Earth, Moscow
2 - Space Research Institute, Moscow
3 - Moscow State University, Moscow
Intense meteorological disturbances of the atmosphere accompanied by the generation of atmospheric
large-scale waves and small-scale turbulence may influence the ionospheric plasma and geomagnetic
field. In search of additional evidence of these effects we analyze the data of electromagnetic and plasma
measurements from low-Earth-orbit SWARM satellites above the hurricane VongFong 2014. These data
show the occurrence of large-scale (about few hundred km) soliton-like disturbances of plasma with
relative amplitudes up to few tens %. These disturbances are supposedly caused by internal gravity waves
generated by the hurricane. The SWARM magnetometers detected in the upper ionosphere above the
hurricane "magnetic ripples" - low-amplitude (0.5-1.5 nT) fluctuations with dominant periods about few
tens of sec. A spot filled with magnetic ripples is produced by field-aligned currents stimulated by
acoustic waves emitted by the hurricane.
NUMERICAL METHODS IN THE PROBLEM OF STUDYING THE EFFECT
OF COSMIC RAYS ON THE EARTH'S ATMOSPHERE
Maurchev E.A.1, Balabin Yu.V., Gvozdevsky B.V., Mikhalko E.A., Hermanenko A.V.,
Belakhovsky V.B.
1 – Polar geophysical institute
[email protected], [email protected]
Primary cosmic rays (CR) include in their composition different types of particles (electrons, various
nuclei and protons, the percentage of which varies within 85-90 percent). Invading the atmosphere of the
Earth, these particles transmit its energy to the substance through a series of successive processes, and if
ionization prevails at a conditional height from 80 km to 10-15 km, then the nuclear-active component
undergoes inelastic collisions in denser layers. As a result, cascades of secondary CRs are formed.
Investigation of the characteristics of these particles (energy spectra, ionization profiles, angular
distributions, altitude profiles) is one of the most important tasks of astrophysics of the CR. At the present
day, mostly experimental methods are used for this, but with the development of information
technologies, numerical models based on the Monte Carlo method are increasingly being used. This
approach makes it possible to significantly expand the field of studying CR in the Earth's atmosphere.
162
In this paper, the results of calculating the passage of CR particles of different types through the
atmosphere of the Earth, obtained with the program complex RUSCOSMICS, are presented. This
software is a development of the PGI team, based on GEANT4 tools and adapted for narrowly focused
tasks.
VALIDATION OF THE RESULTS OF MODELING THE PASSAGE OF
COSMIC RAYS THROUGH THE EARTH'S ATMOSPHERE BY
EXPERIMENTAL DATA
Mikhalko E.A. 1, Maurchev E.A., Germanenko A.V., Balabin Yu.V.
1 – Polar geophysical institute
The corresponding module of the RUSCOSMICS software allows calculating the passage of particles of
cosmic rays (CR) of various kinds through the layers of the Earth's atmosphere, obtaining information
about the energy spectra of the streams, their altitude and ionization profiles, and angular distributions
with a variety of initial conditions. In order for the final result to be the most correct, at the end of the
simulation it is necessary to perform validation. Especially for this, based on the already available
developments of several scientific groups from different institutions, a technique was developed that
makes it possible to compare the experimental data with the results obtained by numerical modeling. In
the work presented, an example of using data from balloons and a ground-based detector of charged
particles is shown.
A NUMERICAL MODEL OF THE HORIZONTAL AND VERTICAL WIND IN
THE EARTH’S ATMOSPHERE AND ITS IMPROVEMENTS
Mingalev I.V.1, Orlov K.G.
1, Mingalev V.S.
1*, Chechetkin V.M.
2 , Mingalev O.V.
1
1 Polar Geophysical Institute, Apatity, Russia
2 Keldysh Institute of Applied Mathematics, Moscow, Russia
E-mail: * [email protected]
To investigate the influence of the space weather on the planetary wind system of the Earth’s atmosphere
not only the experimental and theoretical but also computational studies may be applied. In the Polar
Geophysical Institute, not long ago, the mathematical model of the global neutral wind system in the
Earth’s atmosphere has been developed. The initial version of this model enabled to calculate three-
dimensional global distributions of the zonal, meridional, and vertical components of the neutral wind at
levels of the troposphere, stratosphere, mesosphere, and lower thermosphere. The initial version of this
model, as well as all following versions of the model, are non-hydrostatic, that is, not only the horizontal
components but also the vertical component of the neutral wind velocity is obtained by means of a
numerical solution of a generalized Navier-Stokes equation for compressible gas. Thus, the hydrostatic
equation is not utilized in all versions of this model.
In the initial version of the mathematical model, the internal energy equation for the neutral gas was not
solved in the model calculations. Instead, the global temperature field was assumed to be a given
distribution, i.e. the input parameter of the model, and obtained from one of the existing empirical
163
models. Later, the internal energy equation for the atmospheric gas has been included in the system of
governing equations of the mathematical model. The internal energy equation has been written by using a
relaxation approach, in which a heating / cooling rate of the atmospheric gas in various chemical-
radiational processes is supposed to be straightly proportional to the difference between the real
temperature of the atmospheric gas and an equilibrium temperature of the atmospheric gas. The latter
equilibrium temperature was given by utilizing the global temperature field, obtained from one of the
existing empirical models.
In the initial version of the mathematical model, the Earth’s surface was assumed to be a smooth sphere.
Later, the form of the Earth has been changed from the sphere to an oblate spheroid whose radius at the
equator is more than that at the pole.. Results of simulation indicated that the non-sphericity of the Earth
ought to influence appreciably on the global circulation of the lower and middle atmosphere. In the latter
versions of the mathematical model, it was supposed that the Earth’s surface is smooth. Recently, the
mathematical model has been improved by taking into account the relief of a planet. Therefore, a
planetary surface can contain mountains. The Earth’s surface is approximated by using one of the existing
digital maps of the surface relief of a planet.
Thus, in the last version of the mathematical model, the atmospheric gas is considered as a mixture of air
and water vapor, in which two types of precipitating water (namely, water microdrops and ice
microparticles) can exist. The system of governing equations contains the equations of continuity for air
and for the total water content in all phase states, momentum equations for the zonal, meridional, and
vertical components of the air velocity, and energy equation. The last version of the mathematical model
is based on numerical solving of the system of governing equations and produces three-dimensional time-
dependent distributions of the wind components, temperature, air density, water vapor density,
concentration of micro drops of water, and concentration of ice particles. The system of governing
equations is numerically solved in a simulation domain which is a layer surrounding the Earth globally,
with the relief of a planet being taken into account. The finite-difference method is applied for solving the
system of governing equations. The calculated parameters are determined on a uniform grid. The latitude
and longitude steps are equal to 0.47°, and height step is equal to 200 m. In the last versions of the
mathematical model, parallel computing is utilized for numerical solving the system of governing
equations. The program packages were developed using both CPU, by OpenMP technology, and GPU
NVIDIA, by CUDA technology.
The different versions of the mathematical model have been utilized in order to investigate numerically
how various geophysical conditions influence on the formation of the global wind system of the Earth’s
troposphere, stratosphere, mesosphere, and lower thermosphere.
This work was partly supported by Grant No. 18-29-03022 from the Russian Foundation for Basic
Research.
UPDATING 'CLASSICAL-PHYSICS': EXPERIMENTAL PROOF OF BOTH
NON-EXISTENCE OF EMPTY SPACE PHOTONS MOVING THROUGH IT
K. Mocnik
Space Research Institute
A 'Terrestrial Aberration' (TA) method of measuring the Earth's absolute velocity in contrast to the
Stellar-Aberration (StA) has been proposed by Michelson and Morley in the Supplement of their 1887-
paper, ignored hitherto. TA only is observable if light has been reflected by a mirror in the laboratory.
Both, the historical null-result in the Interferometer-Experiment of Michelson and Morley in conjunction
with our ether-drift measurement did unequivocally prove that the "longitudinal-length-contraction" as
well as the "Photon", and the "empty space", aren't elements of physical reality. An innovative narrative is
proposed telling that the null-result only did prove the wave view of light propagation in the 'ether',
rejecting the 'moving-photon' view of light, if and only if all classical principles (a) Huygens,
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b) Aberration, and c) Doppler) are analyzed on the unifying fundamentals of Euclidean Geometry, thus,
providing a basical update of 'Classical Physics', thus, restoring Maxwell's >ether<.
NEW EVIDENCE OF SOLAR INFLUENCE ON CLIMATE OF NORTH
ATLANTIC AND NORTHERN FENNOSCANDIA
Ogurtsov M.G.1,2
, 2 Jungner H.3
1 – Ioffe PhTI
2 – Pulkovo Observatory
3 – University of Helsinki
email [email protected]
Eight proxy and direct indices of: (a) summer climate in Fennoscandia, (b) sea surface temperature in the
North Atlantic, (c) solar activity were analyzed over the last 3-5 centuries. New evidences of a link
between solar activity, North Atlantic sea surface temperature and summer temperature in Northern
Fennoscandia were obtained using novel and improved data records. It was shown that this relationship is
rather complex and depends on the timescale considered. Possible physical mechanisms of the revealed
connection were discussed. No relationship between activity of the Sun and summer temperature in
Eastern Fennoscandia was found.
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TWO TYPES OF THE MAGNETOSPHERE RESPONSE TO THE
INTERACTION WITH INTERPLANETARY SHOCKS IN THE
GEOMAGNETIC PULSATIONS PSC
Parkhomov V.A.1, Yahnin A.G.
2, Borodkova N.L.
3, Tsegmed B.
4, Tero Raita
5,
Khomutov S.Y.6, Pashinin S.Y.
7, Chilikin V.E.
1, Mochalov A.A.
2
1Baikal State University, Irkutsk, Russia
2Polar Geophysical Institute, Apatity, Russia
3Institute of Space Research, Moscow, Russia
4Institute of Astronomy and Geophysics of the Academy of Sciences of Mongolia, Ulan – Bator,
Mongolia
5 Sodankyla Geophysical Observatory, Finland
6Institute of Cosmophysical Research and Radio Wave Propagation, FEB RAS, Paratunka,
Kamchatka, Russia
7Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia
e-mail: [email protected]
Results of the study of 30 events of interplanetary shocks - magnetosphere interaction for the period 2011
- 2015 are presented. We found two types of the geomagnetic response. During 20 sudden storm
commencement (SSC) cases occurred under interplanetary shock wave (ISW) with velocity <500 km/s
and dynamic pressure jump < 10 nPa on its front, the shocks were accompanied by geomagnetic
pulsations Psc 1-5. In 10 SSC cases, initiated by the ISW propagating with velocity > 500 km/s and
dynamic pressure jump on its front > 10 nPa, a kind of precursor of SSC was revealed, which is a short
duration (3 ÷ 20 s) burst of geomagnetic pulsations in the frequency range of 0.2-11 Hz. On the ground,
the burst of geomagnetic pulsations was observed globally, that is, in different local times and different
latitudes. On spectrograms obtained at different locations, the burst often exhibits a resonant structure
(intermittent increases and decreases of the spectral power at almost multiple frequencies). We suggest
that the resonant structure could be associated with the ionospheric Alfven resonator. It is shown that the
bursts are observed just before the sharp increase in H - component of the magnetic field on the ground;
this is why it can be considered as the precursor of the SSC.
On the basis of the analysis of the event of 22 June 2015 we present detail data confirming the presence
of a precursor of the sudden magnetic impulse (SI) caused by a powerful ISW and developing during the
main phase of the geomagnetic storm. A precursor in the form of a train of oscillations (broadband pulse)
with a falling frequency in the range 0.25 ÷ 11 Hz with duration of ~ 20 s, having a resonance spectrum
structure, is detected globally at 18:33:27 UT by a network of induction magnetometers. No significant
phase delay of the signals in four frequency bands was detected at widely separated observatories. It is
suggested that the pulsations could be excited in the Earth - ionosphere waveguide by a pulse of the
electric field which occurred in the ionosphere as consequence of the short-time impact of the ISW on the
magnetosphere.
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LOCALIZATION OF IONOSPHERE SOURCES OF HIGH-LATITUDE
GEOMAGNETIC PULSATIONS IN 2D FIELD DISTRIBUTIONS
Petlenko A.V.1
1 – Saint-Petersburg Branch of Institute of Terrestrial Magnetism Ionosphere and Radio-Wave
Propagation RAS (SPbF IZMIRAN)
The magnetic field of high-latitude pulsations is determined mainly by the configuration of ionosphere
Hall currents, which can be specified by a curvilinear coordinate grid. This grid is represented by lines of
constant level and isolines of Hall currents, which can be found knowing the positions of the projection
points on the ionosphere of magnetosphere field-aligned currents, as well as their direction and intensity.
The configurations have been examined are initiated by a system of three field-aligned currents and
reproduce well the observed types of peculiarities of the 2D distributions of the magnetic field of
pulsations.
The possibility of determining the intensities of field-aligned currents and their projections to the
ionosphere according to the experimentally constructed distributions of the magnetic field components is
discussed. It is shown that the location of the peculiarities of vertical component and changes in the
curvature of isolines of horizontal component modulus of magnetic field make it possible to localize the
projections of field-aligned currents and changes in their intensities during periods of pulsations’
activation, in particular, to estimate the position of the boundaries of the plasmapause region.
PITCH-ANGLE DIFFUSION OF ENERGETIC PROTONS UPON THEIR
INTERACTION WITH EMIC WAVES: COMPARISON OF THEMIS DATA
ON WAVE SPECTRA AND ENERGETIC PARTICLES
Popova T.A.1, Lyubchich A.A.
1, Demekhov A.G.
1,2, Yahnin A.G.
1
1 - Polar Geophysical Institute, Apatity, Russia
2 - nstitutte of Applied Physics, Nizhny Novgorod, Russia
We analyze several cases of THEMIS spacecraft observations of EMIC waves in proton, He+, and O+
frequency bands in various local time sectors and L shells. We selected the events during which the
energetic proton precipitation was observed by low-orbiting POES spacecraft in the conjugated region.
By using the data on the spectral intensity of EMIC waves, the geomagnetic field, and the plasma density
we calculated the pitch-angle diffusion coefficients of energetic protons for various energies and pitch-
angles. The calculations were performed under the assumption that the ambient plasma consisted of three
ion species, i.e., protons, He+, and O+ ions. The results of calculations were compared with the measured
pitch-angle distributions of energetic protons in the magnetosphere and with the energy of precipitated
protons. On the whole, these parameters of energetic protons are in agreement with those which can be
expected on the basis of the calculated pitch-angle diffusion coefficients.
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THE LATITUDE AND LONGITUDE DISTRIBUTIONS OF COSMIC RAY
CUTOFF VARIATIONS DURING THE MAIN PHASE OF THE MAGNETIC
STORM IN NOVEMBER 2003
Ptitsyna N.G., Demina I.M., Danilova O.A., Tyasto M.I.
St-Petersburg Filial of Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation
(SPbF IZMIRAN)
e-mail: [email protected], [email protected]
Cosmic rays pass through the magnetosphere and are affected by magnetospheric magnetic fields, which
cause changes in the cosmic ray geomagnetic cutoff rigidities GCR (geomagnetic thresholds) and
asymptotic directions of particle arrival during disturbances in the solar wind and magnetosphere. The
geomagnetic cutoff is the threshold rigidity below which the particle flux is zero due to geomagnetic
shielding. Using a method for tracing charged particle trajectories we determined cutoffs numerically in
the Tsyganenko magnetospheric magnetic field model TS01 during the main phase of the geomagnetic
storm on 20 November, 2003. We computed cutoffs on a 5ºx15º latitude-longitude grid at 20:00 UT when
Dst reached the minimum, and cutoffs in the main geomagnetic field (IGRF 2000 model interpolated for
the same moment). It is found that during the storm peak there is a suppression of GCR (ΔR) at low and
middle latitudes in comparison with cutoffs in the main magnetic field up to 1,8 GV. Global distribution
of GCR demonstrates North-South and day-night asymmetries. In the day sector in the northern
hemisphere maximum ΔR occurs at a latitude of ~ 40° and in the southern hemisphere at a latitude of ~
60 º. In the night sector in the northern hemisphere maximum ΔR occurs at a latitude of ~ 55° and in the
southern hemisphere at the latitude of ~ 45°. The observed magnetospheric effects in the distribution of
ΔR are due, apparently, to the dominance of partial ring current which develops at the peak of the storm.
Significant reduction of geomagnetic thresholds on middle and low latitudes has contributed to the
precipitation of additional flux of cosmic ray particles into the Earth's atmosphere that could be
responsible for the low- and midlatitude auroras, widely observed during this magnetic storm.
THE CONTRIBUTION OF THE EARTH'S MAIN MAGNETIC FIELD
VARIATIONS TO AURORAL ACTIVITY IN 1600-1909
Ptitsyna N.G., Demina I.M., Tyasto M.I.
St-Petersburg Filial of Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation
(SPbF IZMIRAN)
Aurora borealis have been observed with the unaided eye for centuries; therefore, they are an
irreplaceable instrument for the study of solar-terrestrial relations and their variations. The number of
observed aurora events can be a measure of the numerical parameters of the solar activity, for instance
Wolf numbers W, for epochs in which they were not instrumentally defined. The yearly number of
observed auroras N depends both on the solar activity and on the configuration and strength of the main
Earth’s magnetic field caused by internal sources. We assessed the contribution of internal sources of
geomagnetic field to the secular variation of low-and mid-latitude aurora occurrences in 17-19 centuries.
For this we have used coefficients of spherical harmonic analysis – the gufm1 model, making it possible
to calculate the Earth’s main magnetic field components in 1600-1909. It is obtained that changes in the
main dipole magnetic moment MM, in 1600-1909 are antiparallel to variations of yearly aurora numbers
N; correlation coefficients are -0.6 -0.8. An empirical model of N as a function of MM was constructed.
We found that in certain periods auroral activity could be influenced greatly by shielding effects of
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geomagnetic field. In particularly, 11-year cycles of solar activity index W are not consistent with 11-year
cycles of N during 1700-1775, and MM influence is responsible for this disagreement. Considering the
contribution of MM improves correlation between N and W. Minimum of N values around 1760
(Silverman minimum) is observed at maximum of solar activity and it seems to be related solely to a MM
increase at that time. The sharp jump in the value of the magnetic moment of the Earth in 1795-1830,
contributes considerably to the decrease of observed auroras during the Dalton minimum.
DIURNAL VARIATIONS OF THE BOTTOM EDGE OF THE IONOSPHERE
DURING THE PROTON PRECIPITATIONS ON AND AFTER 29
SEPTEMBER, 1989
G. F. Remenets 1, M. I. Suhovey
1 , V. A. Shishaev
2
1 - Saint-Petersberg State University, Saint-Petersburg, Russia
2 - Polar Geoghysical Institute, Apatity, Murmansk reg., Russia
Thirty years ago a self-consistent method for solution of an inverse VLF problem in non-stationary
radio path conditions was developed, and it was used for an analysis of 3 different VLF disturbances on
29 September 1989: an ultra-energetic relativistic electron precipitation (04:00 -10:00 UT ), SID at 11:00
UT and a proton precipitation (one of the most powerful event of this type for 70 years ) [1], which began
at 12:00 UT. Its analysis was stopped at 17 UT [2]. The purpose of the present report is to analyze the
development of this precipitation during several days after in the terms of electric conductivity of lowest
ionosphere fringe.
The named conductivity is characterized by 2 parameters: by an effective height h(t) and by a value of
reflection coefficient module R(t, ( h)) for first ionosphere ray in a model of effective waveguide with
h. The argument of complex R(t, ( h)) is equal to for sliding angles of ray incidence and for a
middle working frequency 12.1 kHz. Our work is bounded by sunset hours (15:30 – 18:30 UT). For this
time the most “criminal” supposition is done: at every time moment a model waveguide is homogeneous
along the radio path. Our estimation has shown that the corresponding systematic error is comparable
with the apparatus phase error of the experimental data used (1 mcs).
We compared quantitatively the daily variations of solar proton fluxes, which began on September 29,
1989, 12:00 UT, with the sunset changes of VLF signals for a completely auroral radio path Northern
Norway - the Kola Peninsula (Aldra - Apatity). For realization of this purpose we have used the satellite
data, the experimental VLF data of the Polar Geophysical Institute of the Kola Science Center, RAS,
Apatity, Murmansk region and a self-consistent method of a VLF inverse problem solving [2]. The
pointed method for an analysis of VLF daily variations without the precipitations was used earlier.
We have established the following: i) The presented graphs on Fig. 1 give an error estimate of the
method by comparing the analysis of sunset VLF variations for the positive direction of time (solid lines)
with the analysis for the negative direction of time (dashed lines). Each of these analyses, based on a
solution of inverse VLF problem by self-consistent method and which did not use any geophysical data,
was fulfilled independently. ii) With the change of proton flux density in the period from September 29 to
October 2, 1989 the daily variation of the effective height h at sunset changed from 5 km on September to
10 km on October and the reflection coefficient of first ionospheric ray at a sunset was constant. In this
date period a value of effective altitude changed from 47 km to 54 km at 15:00 UT, from 52 to 64 km at
19:00 UT and a value of reflection coefficient has changed from 0.8 to 0.6. iii) From October 3 to
October 5, the proton flux density has not yet come to its undisturbed value but has seriously weakened
significantly.
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In a real wave guide there is none ray mode because of wave length comparability with the altitude
scale of inhomogeneity of electric conductivity, but it was shown numerically several decades ago that an
effective height h was placed inside the significant lay of conductivity for radio wave reflection. Roughly
speaking the h is an analog of weight center for a solid.
Fig.1.The sunset changes of electric atmosphere properties before (Sept. 28) and during the solar proton
precipitations in the terms of effective height (altitude) h.
References:
[1] Miroshnichenko Leonty, Curt A. de Konong, R. Perez-Enriques. Large solar event of September 29,
1989: Ten years after // Space Science Reviews. Feb 2000. Vol. 91. Issue 3. P. 615-715.
[2] Remenets, G. F. and M. I. Beloglazov. Dynamics of an auroral ionospheric fringe at geophysical
disturbances on 29 September 1989 // Planet. Space Sci. 1992. Vol.40. P. 1101-1108.
BALLOONING INSTABILITY OF COUPLED MHD MODES IN 2D MODEL
OF THE MAGNETOSPHERE
Rubtsov A.V.1, Mager P.N.
1, Klimushkin D.Yu.
1
1 – Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia
In this study we investigates the conditions of the ballooning instability of the coupled Alfvén and slow
magnetoacoustic modes in the dipole model of terrestrial magnetosphere with taking into account
inhomogeneity of plasma and magnetic field in the direction along the magnetic field lines. The
instability is found to develop on the slow magnetoacoustic oscillation branch, but necessarily with taking
into account the coupling with the Alfvén mode. The symmetric (with respect to the magnetic equator)
modes more unstable than antisymmetric ones. For the symmetric case, the instability threshold depends
on plasma compressibility: the finite sound velocity raises the instability threshold. For all other equal
conditions, the instability threshold decreases with the decrease of the field line curvature radius on the
equator. Thus, in the geomagnetic tail the instability has more chances to develop than in the region with
the dipole field lines.
This study was supported by the Russian Science Foundation under grant 18-17-00021.
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PC5 COMPRESSIONAL EVENT OBSERVED WITH THEMIS: SPATIO-
TEMPORAL STRUCTURE, WAVE-PARTICLE INTERACTIONS
Rubtsov A.V.1, Agapitov O.V.
2, Mager P.N.
1, Klimushkin D.Yu.
1, Mager O.V.
1
1 – Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia
2 – Space Science Laboratory, University of California, Berkeley, CA, USA
The compressional high-m Pc5 wave associated with the localized hot proton injection was observed by
THEMIS mission spacecrafts in the dusk sector of the magnetosphere at L ~ 10. The wave was
propagating in energetic proton drift direction with azimuthal wave number m ~ -60. The transverse
magnetic field of the wave was primarily poloidal. The pulsation followed two consecutive substorms: the
cloud of energetic particles comprised of the lower energy protons from the earlier substorm and higher
energy protons from the subsequent one. The clear signatures of the wave-particle drift resonances as
proton fluxes modulation by the wave were observed. The wave frequency was about two times less than
the corresponding Alfvén wave eigenfrequency on the same L-shells and there is a strong dependence of
the wave’s frequency on the m number. The supposed generation mechanism is the gradient instability.
The increase of the particle energy from the Earth constitutes the conditions for the gradient instability of
the drift compressional mode, since for the Alfvén mode the particle energy must decrease. Thus, we
conclude that the observed wave was drift compressional mode generated by the gradient instability.
This study was supported by RFBR under grant 16-05-00254.
ALFVÉN WAVES AS A DRIVER FOR MAGNETOSPHERIC DYNAMICS
V. Semenov1, M. Kubyshkina
1, I. Kubyshkin
1, N. Erkaev
2,3, E. Gordeev
1, M. Shukhtina
1,
V. Sergeev1
1 – Saint Petersburg State University, Saint Petersburg, Russia
2 - Institute of Computational Modelling SB RAS, Krasnoyarsk, Russia
3 - Department of Applied Mechanics, Siberian Federal University, Krasnoyarsk, Russia
We analyze the 11-year period of solar wind (SW) and Interplanetary Magnetic Field (IMF) data and
reveal the disproportion in the distribution of the product of IMF Bx component and SW velocity vz-
component for different signs of IMF Bz . This disproportion can be explained if we admit that about 70%
of IMF Bz-component are transported to the Earth’s orbit by Alfven waves. The explanation is further
supported by the fact, that the disproportion increases in the years of solar cycle maximal activity and
decreases during the low solar activity years.
We also show that the same unbalance in (Bx vz ) distribution grows notably before a substorm onset,
with slow increase during first 40 minutes of growth phase (we use 1 hour period before a substorm onset
as a growth phase for generality) and sharp increase in the last 10-20 minutes before onset. Thus, the
change in sign of (Bx vz) may be treated like an additional trigger for a substorm breakup. The
explanation we suggest for this phenomenon is the efficient displacement of the magnetospheric plasma
sheet by both IMF Bx and SW flow vz, which move plasma sheet in the same direction if the sign of
(Bx vz) is negative under negative Bz or positive under positive Bz . The displacement of current sheet, in
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its turn, increases the asymmetry of the magnetotail and the plasma sheet and can alter the threshold of
substorm instabilities.
DEPENDENCE OF ENERGETIC PROTON PRECIPITATION
EQUATORWARD OF THE ISOTROPY BOUNDARY ON GEOMAGNETIC
ACTIVITY
N. V. Semenova1, T. A. Yahnina
1, A. G. Yahnin
1, and A. G. Demekhov
1, 2
1 Polar Geophysical Institute, Apatity, Russia
2 Institute of Applied Physics, Nizhny Novgorod, Russia
e-mail: [email protected]
Energetic proton precipitation equatorward of the boundary of isotropic fluxes (EPPEBIF) is the
consequence of the ion-cyclotron instability (ICI) developing in the vicinity of the equatorial plane of the
magnetosphere. Thus, the precipitation can be used for statistical studies of the EMIC wave occurrence.
The global distribution of the occurrence rate of EPPEBIF is constructed on the basis of the data from
four POES satellites that operated during July-December of 2005. The distribution exhibits the maximal
occurrence on the dayside at distances behind the geostationary orbit. This agrees with the EMIC waves
occurrence in the magnetosphere. It is also shown that maximal occurrence rate of the precipitations
increases with the increase in the solar wind dynamic pressure independently of the geomagnetic activity
level. We demonstrate that the maximal occurrence rate on the dayside increases when the geomagnetic
activity changes from low to moderate, and it decreases during the higher activity. Such behavior can be
explained by the effect of the two competitive processes, both of them are due to the nightside injections
of energetic protons. On the one hand, the injections lead to growth of particle flux, which, in turn, causes
the increase of ICI increment. On the other hand, the injections lead to the decrease of the radial gradient
of the particle flux on the nightside. This results in the decrease of transverse anisotropy of energetic
protons on the dayside and diminishes the ICI increment.
ADVANCES IN MAGNETOTAIL MONITORING DURING SUBSTORMS
Sergeev, V.A. 1, N.A. Tsyganenko
1 , E.I. Gordeev
1, V.G. Merkin
2, M.I. Sitnov
2, V.
Angelopoulos3, A.V. Runov
3
1- St.Petersburg State University
2- Applied Physics Laboratory, John Hopkins University
3- University of California Los Angeles
Statistical analyses of magnetotail observations provides gross features of magnetotail configuration
changes during substorms, but misses the individual details and variability during individual events.
Recently we showed how the energetic electron observations from polar orbiting spacecraft can reveal
magnetotail topology changes during strong solar electron events when the high flux of energetic
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electrons-tracers are available. (1) For the substorm growth phase we were able to show an isolated
event in which latitudinally-localized region of anisotropic 30 keV electron loss cone embedded in the
isotropic solar electron precipitation was persistently observed for more than 0.5 hour by six POES
spacecraft which crossed the premidnight auroral oval. Such embedded anisotropic regions were observed
~1deg poleward of the outer radiation belt boundary over 4-5 hours wide MLT sector, suggesting a
persistent ridge-type BZ/j maximum in the equatorial plasma sheet at distances 15-20Re. We discuss
unfrequent observation of such events taking into account recent results of global MHD simulations.
(2). As regards steady magnetospheric convection (SMC) events, we analyzed a rich collection of
observations during ~10 hours of strong, steady solar wind driving to show that, following a southward
turning of the interplanetary magnetic field (IMF) and a subsequent 3-4 hour period of large-scale
substorm related reconfigurations and plasma injections, the near-Earth magnetic configuration evolved
into a non-standard type which lasted until the end of this SMC event (five hours). During that time a
dipolarized region with complicated Bz landscape persisted in the midtail while the configuration was
very stretched in the near tail. This was manifested as a highly depressed magnetic Bz component at
geostationary orbit and as persistent non-adiabatic electron scattering at the periphery of the outer
radiation belt. In addition, in situ observations suggest that a thin current sheet extended longitudinally
toward the dawn terminator. In the return convection region near the terminator, observations of this
azimuthal current sheet were sporadically interrupted/modulated by earthward-convecting plasma
structures, either remnants of reconnection-produced plasma bubbles or flapping waves.The hybrid
magnetotail configuration (dipolar in the mid-tail and stretched in the near tail) observed during this long-
duration SMC event poses a challenge for empirical magnetospheric modeling.
INNER MAGNETOSPHERE RECONFIGURATION DURING THE
SUBSTORM GROWTH PHASE
M. A. Shukhtina 1, E. I. Gordeev
1, V. A. Sergeev
1
1Dept.of Earth’s Physics, Saint-Petersburg State University, St. Petersburg, Russia
email: [email protected]
It is well known that during the substorm growth phase magnetotail magnetic field stretching and plasma
sheet thinning are observed. For several decades this effect was entirely attributed to open magnetic flux
accumulation (OMFA) in the tail lobes, leading to tail flaring increase, magnetotail pressure rise and
plasma sheet thinning. However, recently Hsieh and Otto (2014) proposed another scenario, including
closed magnetic flux depletion (CMFD) in the inner magnetosphere. This effect results from enhanced
convection in the inner magnetosphere, caused by electric field propagating from the dayside
reconnection site. Hsieh and Otto (2014) tested this mechanism on regional 3-D MHD model, whereas
Gordeev et al. (2017) used self-consistent global MHD simulations. Gordeev et al. (2017) confirmed the
importance of CMFD process which, according to their estimates, amounts ~30% of OMFA value.
In our work we tried to estimate the CMFD and OMFA values experimentally based on simultaneous
observations of Cluster and Geotail spacecraft in the inner (<X1>~-10 RE) and middle (<X2>~-21 RE) tail
lobes. The closed magnetic flux value was estimated as the difference between the magnetic flux values
through tail cross-sections at X1 and X2. Validity of such approach was shown on global MHD tests.
Afterwards the experimental results were compared with MHD calculations of the closed magnetic flux
between X=-7 and -20 RE. According to experimental estimates CMFD is about 50% of OMFA, in rough
agreement with MHD.
The obtained results confirm the existence of two decoupled magnetotail domains with different regimes
during the substorm growth phase. In the midtail plasma sheet with 2-D magnetic configuration
convection is depressed, being enhanced in the inner magnetosphere in the form of azimuthal flux
transport.
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Hsieh, M.-S., and A. Otto (2014), The influence of magnetic flux depletion on the magnetotail and
auroral morphology during the substorm growth phase, J. Geophys. Res. Space Physics, 119, 3430–3443,
doi:10.1002/2013JA019459.
Gordeev, E., V. Sergeev, V. Merkin, and M. Kuznetsova (2017), On the origin of plasma sheet
reconfiguration during the substorm growth phase, Geophys. Res. Lett., 44, doi:10.1002/2017GL074539.
RING CURRENT PROTON DYNAMICS DRIVEN BY WAVE-PARTICLE
INTERACTIONS DURING A NONSTORM PERIOD
Smolin S. V.
Siberian Federal University, Department of Theoretical Physics, Krasnoyarsk, Russia
It is used correlated observation of enhanced electromagnetic ion cyclotron (EMIC) waves and dynamic
evolution of ring current proton flux collected by Cluster satellite near the location L = 4.5 during March
26-27, 2003, a nonstorm period (Dst > -10 nT). Energetic (5-30 keV) proton fluxes are found to drop
rapidly (e.g., a half hour) at lower pitch angles, corresponding to intensified EMIC wave activities.
As mathematical model is used the non-stationary one-dimensional pitch angle diffusion equation which
allows to compute theoretically density of phase space or pitch angle distribution of the charged particles
in the Earth’s magnetosphere. The model depends on time t, a local pitch angle and several parameters
(the mass of a particle, the energy, the McIlwain parameter, the magnetic local time or geomagnetic
eastern longitude, the geomagnetic activity index, parameter of the charged particle pitch angle
distribution or the pitch angle distribution anisotropy index but is taken for the 90 degrees pitch angle at t
= 0, the lifetime due to wave-particle interactions). This model allows to estimate also for different
geophysical conditions a lifetime due to wave-particle interactions.
It is shown, that EMIC wave can yield decrements in proton flux within 30 minutes, consistent with the
observational data. The good consent is received. The presented model and results of numerical
calculations will promote the further understanding of ring current proton dynamics driven by wave-
particle interactions under different geomagnetic activities.
THE SIMPLE ANALYTICAL DESCRIPTION FOR RELATIVISTIC (>2 MEV)
ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT
Smolin S. V.
Siberian Federal University, Department of Theoretical Physics, Krasnoyarsk, Russia
It is used the observation of relativistic (>2 MeV) electron fluxes combined and averaged by local hour
around geosynchronous orbit from 1995 to 2009 collected by GOES satellite. The flux distribution in
local time (LT) peaks near noon (between 1100 and 1200 LT) and sees its minimum near midnight
(between 2300 and 0000 LT). The average value of this flux distribution that is the daily average can be
significantly less than the maximum flux.
As the analytical description is offered the simple formula for definition of a perpendicular (for a pitch
angle of 90 degrees) integrated flux of relativistic (>2 MeV) electrons at geosynchronous orbit which
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depends on the magnetic local time (LT) or geomagnetic eastern longitude, the McIlwain parameter L, the
geomagnetic activity index Kp and the perpendicular integrated flux of relativistic (>2 MeV) electrons
but taken at LT = 0 hr.
This formula can be considered as the first approximation for any perpendicular integrated flux in a
geosynchronous orbit, when L = const and Kp = const or Kp approximately const.
Comparison of analytical dependence with experimental data of satellite GOES in a geosynchronous orbit
of the Earth is made. The good consent is received, especially with 0000 LT up to 1100 LT and with 1800
LT up to 2400 LT.
GEOMAGNETIC DISTURBANCES WITH SUDDEN AND GRADUAL
COMMENCEMENTS IN 1869-1954 ACCORDING TO OBSERVATORY
DATA AND CATALOGS OF STORMS
Sergey Sokolov1, Vadim Soldatov
1, Vladimir Koshelevsky
1
1 – SPbF IZMIRAN
email: [email protected]
Observations of variations in the geomagnetic field and the magnetic activity indices based on these
observations are the only source of information about "geomagnetic weather" in the late 19th – first half
of the 20th century. The aa indices, calculated from 1868, allow us to distinguish periods of magnetic
storms of different magnitude and duration. Information on disturbances can be obtained directly from
observational data at observatories, as well as from storm catalogues compiled from local observations on
some of them. To understand how the geomagnetic activity changed during eight 11-year solar cycles
(1869-1954), we used the magnetograms and the catalogues of storms. On the basis of aa-indices we
selected periods during which the maximum value of aa-index (aamax) exceeded 30 (Kpa_max > 3) for more
than three hours. These periods were considered disturbed, and it was taken into account that within
themselves they could have quiet intervals with a duration of up to 18 hours. Depending on the values of
aamax, each event was assigned a corresponding rank. Data on sudden commencement (SC) storms helped
to distinguish storms with SC among selected disturbances. The resulting sampling divides the
disturbances by magnitude and by type of commencement – sudden or gradual (GC). A comparison of the
obtained list with the catalogs data showed that the latter, as a rule, included disturbances with aamax > 95
(Kpa_max > 5) only; smaller events were not included. Some storms in the directory wrongly attributed to
disturbances with GC, not SC. This is indicated by the data of the endorsed list of SCs
(http://www.obsebre.es/en/rapid) and our review of the magnetograms of the observatories of St.
Petersburg and Pavlovsk; they show almost all SCs from the above list. Our catalog includes 4620 storms:
1340 with SC and 3280 with GC. Using it, we found out how the number of storms of different
magnitude (with SC and GC) changed depending on the number of sunspots and at different phases of
solar cycles. It is shown, in particular, that during the period considered there was a faster growth of
storms with GC than with SC.
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SPATIAL-TEMPORAL CHARACTERISTICS AND PHYSICAL NATURE OF
THERMAL ANOMALY DIAGNOSED BY THE EISCAT RADAR WITHIN
THE DUSTED NIGHTSIDE AURORAL DYNAMO LAYER
E.E. Timofeev,1 S.L. Shalimov,
2,3 M.K. Vallinkoski,
4 J.Kangas
4
1 Admiral Makarov State University of Maritime and Inland Shipping, Saint-Petersburg, Russia.
2 Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
3 Space Physics Institute of the Russian Academy of Sciences, Moscow, Russia
4 Space Physics Department of the University of Oulu, Oulu, Finland
In the present study we analyze parameters of the lower ionosphere, measured by the EISCAT radar
facility at the magnetic zenith of Tromsø auroral observatory during the ERRRIS campaign. Data used
consists of 19 different nights of observations and includes about 2000 simultaneous measurements of 5
parameters of the dynamo layer plasma at each of the three altitude levels:, 106, 110 and 115 km.
Namely: the temperatures of the ions (Ti) and electrons (Te), electron density (Ne), modulus and azimuth
of the ionospheric electric field vector (E-field). The level of meteoric dust in the lower ionosphere was
monitored according to the IMO website. The subject of the analysis is further study of the spatial-
temporal characteristics of the temperature anomaly (TA= (Ti - Te) described earlier, for example, in our
report to the COSPAR-2014. The main feature of the anomaly contradicts all modern models of physics
of the lower ionosphere. Namely: Te is (50-100 K) lower than Ti.
The analysis showed that
1) 75% and 25% of the ERRRIS data corresponds to modulus E-field that is below and above the
threshold of the Farley-Buneman (FB-instability), respectively
2)The altitude profile of the thermo-anomaly reaches a maximum at an altitude of 106 km. Wherein, its
average value (TA=~50 K) is equal to its STD value. While the E-field module was in the range of 20-25
mV/m, that is just below to the normal threshold of the FB-instability;
3) At an altitude of 110 km, the average value of TA is no more than (~ 20 K), which is almost twice as
low as STD of T.A. at this altitude. The maximum is achieved with smaller values of the E-field
compared with a height of 110 km: namely, in the range 15-20 mV/m. At each of the heights (106 and
110 km), further growth of the E-field module above the FB-turbulence threshold leads to explosive
growth of the STD values, i.e. to the rapid destruction of the thermo-anomaly.
4) A rare single interval of radar measurements lasting no more than 15-20 minutes in the event of
01.04.1988 demonstrated the fundamental possibility of forming a thermo-anomalous structure at
altitudes near the lower edge of the heights of the dynamo layer. Namely, at an altitude of 102 km. At the
same time, the values of the thermal anomaly (from 20 to 60 K) were not destroyed even under conditions
of growth of the E-field modulus up to 35 mV / m.
5) The constant anti-correlation of the temporal variations of the ion (dTi) and electron (dTe)
temperatures on the time scale of the pulse duration of the EISCAT radar (~90 C) was detected under the
conditions of the thermo anomaly. The correlation coefficient was calculated from samples of 16 to 25
consecutive radar pulses. Near the threshold of the FB instability (15-25 mV/m), this coefficient reaches a
maximum near (0.9), and then falls sharply to zero with a further increase in the E-field.
6) As it turned out, there are both upper and lower limits of electron density, for which the magnitude of
the thermo-anomaly is already close to zero. The lower limit of the Ne density is ~ 1.5x104/cm3. The
values of the limiting electron density are different for altitudes of 106 and 110 km. Namely: ~ 25 and ~
35x104/cm3 for heights of 106 and 110 km respectively.
The physical nature of the thermo-anomaly is interpreted on the basis of the electron cooling effect
known from the theory , as well as from experiments in nonideal laboratory plasma, due to the
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precipitation of the "hot tail of the electron distribution function" on the particles of metallic dust. Under
the conditions of meteor stream intrusions, the plasma of the night auroral dynamo layer becomes a three-
component: ions, electrons and negatively charged metal macro- particles of meteoric dust. At the same
time, the overwhelming majority of the energy of a dusty plasma is concentrated in dust particles.
Therefore, under such adiabatic conditions, antiphase variations of the electron and ion temperatures are
observed.
CRITERIA FOR VULNERABILITY OF POWER TRANSFORMERS
ELECTRIC POWER SYSTEMS WITH PERTURBATION OF COSMIC
WEATHER
Vahnina V.V., Kozub A.A. Dubinin M.V.
Togliatti State University
During sudden changes in space weather, which are accompanied by increased geomagnetic activity,
between grounded neutrals of power transformers of electric power systems (EPS) a potential difference
arises that causes high voltage and phase conductors of the quasi-permanent current (QPC) transmission
lines to flow along high-voltage earthed windings. The latter is commonly called a geo-induced current
[1]. The frequency of the QPC is not higher than 0.1 Hz, which is many times less than the nominal
frequency (50 Hz) of the mains voltage. The magnitude of the QPC can be quite commensurate with the
rated current of the power transformers of the EPS [2].
The main effect of QPC with increased geomagnetic activity in the unilateral saturation of the magnetic
system of power transformers. In this case, non-sinusoidal magnetizing currents increase many fold. This
is equally dangerous, both for power transformers, and for additional heating, windings, magnetic circuit,
oil, structural elements, and for regimes EPS, since the consumption of reactive power is increasing and
the quality of electric power in the electric network is deteriorating [3]. Therefore, the actual task is to
adequately assess the degree of influence, QPC caused by space weather perturbations, to the depth of
unilateral saturation of power transformers with different design of the magnetic system-rod, armored rod
and armor design.
Modeling of magnetic fields under the influence of QPC on power transformers, taking into account the
design of the magnetic circuit, is performed in the program FEMM 4.2 [4]. It is shown that on power
transformers with a rod structure of a magnetic system, a "strong" effect can only be quasi-permanent
currents whose magnitude is higher than the rated current of the high-voltage winding.
The intensity of the effect of cosmic weather perturbations on the magnetic system of power transformers
with different design of the magnetic system is suggested to be estimated by the saturation coefficient ks.
The saturation coefficient ks characterizes the intensity of magnetization of the structural elements of the
magnetic systems of the power transformers of the EVC from the value of the magnetizing current IQPC.
It is proposed, for power transformers with the armor design of the magnetic system, the saturation
coefficient to be assumed equal to unity ks = 1. For transformers with armored rod structure of the
magnetic system, ks = 0.4 ÷ 0.5. Power transformers with a rod structure of a magnetic system are
practically not affected by the geo-induced QPC, and for them the saturation coefficient is zero ks = 0.
LITERATURE
1. Boteller D.H. The influence of geomagnetic inductive current B.C. Hydro 500 kV - System. IEEE
Trans. Power Deliv., 1989, vol. 4, No. 1. P.818-823.
177
2. Pirzhala R. The influence of the interaction of stations on the calculation of geomagnetically induced
currents in electric power transmission systems. Planet Earth Planet, 2008, 60. P.743-751.
3. Kappenman J.G. Geomagnetic storms and their impact on the US electrical network. Metatech
Corporation 358 S. Fairview Ave., Suite E Goleta, CA 93117, January 2010. 197 pp.
4. Meeker D.C. FEMM 4.2. Magnetostatic teaching aid. URL:
http://www.femm.info/Archives/doc/tutorial-magnetic.pdf.
MANIFESTATION OF 60-YEAR CLIMATIC CYCLE IN CORRELATION
LINKS BETWEEN SOLAR ACTIVITY AND THE LOWER ATMOSPHERE
CIRCULATION
Veretenenko S.V., Ogurtsov M.G.
Ioffe Institute
Temporal variability of correlation links observed between characteristics of the lower atmosphere and
solar activity on the multi-decadal time scale remains one of unresolved problems of solar-terrestrial
physics. In this work we continue studying possible reasons for this variability. Temporal behavior of
correlation coefficients between troposphere pressure at extratropical latitudes and sunspot numbers was
compared with long-term changes in frequency of occurrence of large-scale circulation forms according
to Vangengeim-Girs classification, as well as with the evolution of the stratospheric polar vortex and
global temperature anomalies. It was shown that a roughly 60-year periodicity revealed in the amplitude
and sign of solar activity/galactic cosmic ray (SA/GCR) effects on extratropical cyclogenesis intensity [1]
is closely related to large-scale circulation epochs. The detected sign reversals of correlation links
between troposphere pressure and SA/GCR variations were found to coincide with turning points in the
evolution of the main forms of atmospheric circulation which are accompanied by transitions of the polar
vortex from its strong state to a weak one and vice versa. This allows suggesting that the detected
correlation reversals are caused by changes of troposphere-stratosphere coupling associated with changes
of the vortex strength. It was shown that the changes of the polar vortex state and the corresponding
changes in large-scale circulation epochs may be related to global temperature anomalies which also
reveal a roughly 60-year variation. It was suggested that a possible reason for this temperature variation
may be long-term changes of total solar irradiance.
Veretenenko S., Ogurtsov M., 2012. Regional and temporal variability of solar activity and galactic
cosmic ray effects on the lower atmosphere circulation. Adv. Space Res. 49(4), 770–783.
LONG-TERM NORTH-SOUTH ASYMMETRY
OF THE SOLAR MAGNETIC FIELD
Vokhmyanin M., Zolotova N., and D. Ponyavin
St Petersburg University
Various solar magnetic field manifestations are north-south asymmetric in amplitude and phase. We
analyze the offset of the heliospheric current sheet (HCS) from the ecliptic plane and sunspot areas over
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19 and 20 centuries. We found that both parameters experience simultaneous changes in terms of
dominating hemisphere around solar activity cycles 14-15 and 19-20. The same phenomenon is observed
in the differential rotation velocity. We suggest that these north-south asymmetries originate from the
same global source and vary regularly with nearly centennial periodicity.
RECONSTRUCTION OF PARAMETERS
OF THE SOLAR ACTIVITY IN XVII CENTURY
N. Zolotova1, M. Vokhmyanin
1
1 - Saint-Petersburg state university
[email protected]; [email protected]
Records on the solar activity in the distant past provide an important information on the eventual crucial
changes in the physical parameters of the solar activity during the so-called Grand-minima. In this work
we present the state of art of the sunspot activity reconstruction from historical observations by Galilei,
Harriot, Scheiner, Gassendi, and Hevelius from 1610 to 1644. Behaviour of the butterfly diagram, sunspot
areas and numbers, differential rotation, quality of observations are analysed and compared to the modern
ones.
VERIFICATION OF THE OMNI DATABASE USING PC INDEX
Vokhmyanin M.V., Stepanov N. A., Sergeev V. A
1 - St. Petersburg State University, Earth Physics Department, St. Petersburg 198504, Russia
2 - Arctic and Antarctic Research Institute, St. Petersburg, Russia.
[email protected] [email protected] [email protected]
OMNI database of solar wind parameters is compiled from ACE, WIND, GEOTAIL and IMP8
measurements which are time-shifted to the bow shock nose. In order to check the reliability of the OMNI
data, we compare EKL = VBxysin2(θ/2) from the OMNI data and according to GEOTAIL measurements
made near the subsolar point (within 5 Re from the GSE X axis). PC index of geomagnetic activity is
designed as a proxy of EKL and can serve as another indicator of OMNI data quality. We analyze
correlation between 1-min EKL and PC index variations within 2-hour intervals. The correlation analysis
fails when the amplitude of the EKL variation is low, therefore we consider intervals with ΔEKL greater
than 1.5 mv/m. For about 15% of intervals high correlation between OMNI and GEOTAIL EKL
corresponds to low correlation between OMNI EKL and PC index. For the rest majority of the analyzed
cases the higher (lower) the OMNI-GEOTAIL correlation the higher (lower) the OMNI-PC correlation.
Therefore using the PC index we can filter intervals of “good” OMNI data corresponding to the solar
wind near the bow shock nose.
Parameters of the interplanetary magnetic field and solar wind plasma during periods of 163 isolated
substorms were have been investigated. It is shown that the solar wind velocity V and plasma density N
remain approximately constant for at least 3 h before the onset of the substorm onset expansion phase То
and 1 h after То. On average, the velocity V of the solar wind exhibits a stable trend toward
anticorrelation with its density N over the whole data array. However, the situation is different if the
values of V and N are considered with respect to the intensity of substorms observed during that period.
These substorms appear on the background of an increase both in the solar wind velocity and solar wind
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plasma density levels, which is observed in the substorm maximum with an increase in the magnitude of
the AL magnetic activity index. With the growth of substorms intensity, quantified as the maximum
absolute value of AL index, there observed an increase in both the solar wind plasma velocity and
density, at which these substorms appear. It has been is found that the magnitude of the solar wind
dynamic pressure P is closely related to the magnetosphere energy load defined as averaged values of the
Kan-Lee electric field EKL and Newell parameter dФ/dt averaged for 1 h interval before То. The growth
of the dynamic pressure is accompanied by an increase in the load energy necessary for substorm
generation. This interrelation between P and values of EKL and dФ/dt is absent in other, arbitrarily
chosen periods. It is believed suggested that the processes accompanying increasing dynamic pressure of
the solar wind result in the formation of magnetosphere conditions that increasingly impede substorm
generation. Thus, the larger is P, the more solar wind energy must enter the Earth's magnetosphere during
the period of the growth phase for substorm generation. This energy is later released during the period of
the substorm expansive phase and creates even more intense magnetic bays.
RELATIVISTIC ELECTRON PRECIPITATION AND GEOMAGNETIC
ACTIVITY
A. G. Yahnin, T. A. Yahnina, and N. V. Semenova
Polar Geophysical Institute, Apatity, Russia
e-mail: [email protected]
We considered ~1500 REP events during three 184-day (half of year) intervals for magnetically
“disturbed” (2005), ”quiet” (2009) and moderately disturbed (2011) epochs. All events were divided into
three groups according to criteria by Yahnin et al. [2016, 2017]. It was suggested that these groups
correspond to different mechanisms of the precipitation. Each group of the REP events exhibited different
percentage during the abovementioned intervals. This may mean that the relative contribution of different
mechanisms to the production of precipitation from the radiation belt varies depending on geomagnetic
activity.
For each group the dependence of the REP occurrence rate and intensity on geomagnetic activity was
investigated. It was shown that for each group the probability of the REP observation increases when
geomagnetic activity grows. At the same time for each group, the REP flux does not depend of on the
current geomagnetic activity. However, the average of the REP flux for some time interval was found to
be proportional to mean values of the geomagnetic activity indices corresponding with this interval.
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SIMULTANEOUS OBSERVATIONS OF EMIC AND VLF WAVES DURING
MULTIPLE MAGNETOSPHERE COMPRESSIONS
A.G. Yahnin1, J. Manninen
2, T. Raita
2, T.A. Yahnina
1, E.E. Titova
1, A.G. Demekhov
1,3
1 Polar Geophysical Institute, Apatity, Russia
2 Sodankyla Geophysical Observatory, Sodankyla, Finland
3 Institute of Applied Physics of RAS, Nizhniy Novgorod, Russia
e-mail: [email protected]
A series of simultaneous EMIC and ELF/VLF wave bursts were observed onboard the Van Allen probes
(VAP) during the event of multiple magnetosphere compressions on 14 Sept 2017. The bursts, which
have duration and cadence of several minutes, were observed during about four hours when the spacecraft
were on the day side and went through the apogee. Similar temporal structures of the emissions were
detected on the ground in the Pc1 and ELF/VLF ranges by the network of induction coil magnetometers
and by the ELF/VLF receiver in Kannuslehto, respectively. Combining the VAP and ground-based wave
data with particle precipitation data from low-orbiting POES satellites allowed us to identify the
precipitation pattern associated with both ELF/VLF and EMIC waves. This is the enhancements of
precipitating >30 keV energetic electrons and protons, which are localized within the zone of anisotropic
fluxes at L>4. This precipitation occupies the area around noon and has dimensions as large as 1-4
degrees in latitude and several hours in MLT. The area of the precipitation significantly varies in time.
We conclude that this kind of precipitation is the result of pulsed development of the co-located ion-
cyclotron and electron-cyclotron instabilities stimulated by enhancements of the transverse anisotropy of
the ring current and outer radiation belt particles due to multiple magnetosphere compressions.
ACCELERATION OF COLD ION COMPONENT AT THE SEPARATRICES
DURING COLLISIONLESS MAGNETIC RECONNECTION.
I. Zaitsev1, A. Divin
1, V. Semenov
1
1 – Saint-Petersburg State University
We present kinetic simulations of magnetic reconnection in the presence of low-energy ion population
performed with a Particle-in-cell code iPIC3D. Simulation results are compared to conventional
reconnection pattern obtained with upstream plasma beta =1. We propose a model of cold ion
energization by means of acceleration with normal (Hall) electric field existing at the separatrices. Cold
ion component appears to be much more sensitive than the hot one to small-scale electrostatic field due to
the smallness of the initial gyroradius. Electrostatic potential drop leads to outflow-directed bulk
acceleration with formation of deep density cavities. Simulations with hot ion component only indicate
that the potential well scatters the particles in such a case when the gyroradius exceeds the gradient scale
of electric field. Test particle simulations are performed in order to study how cold and hot ions pass
through the small-scale electric field inhomogeneity. The resulting ion scattering/acceleration depends on
the ratio of the initial particle gyroradius to the potential well width.
181
TRIGGER REGIME OF THE MAGNETOSPHERE DYNAMICS IN THE
SOLAR ACTIVITY CYCLE
O.D. Zotov1, B.I. Klain
2, N.A. Kurazhkovskaya
3
1,2,3 Borok Geophysical Observatory, Branch of Schmidt’s Institute of Physics of the Earth,
Russian Academy of Sciences (IPE RAS), Borok, Yaroslavl oblast, Russia
e-mail: [email protected]; [email protected]; [email protected]
The work is devoted to the study of the features of the Earth’s magnetosphere dynamics. It is shown that
in each of the 11-year cycles of solar activity the dynamics of the magnetosphere activity (Ap and AL-
indices) demonstrates a sharp transition (trigger mode) from the “periodic” regime (low level of
broadband noise, the presence of a 27-day periodicity) to a “chaotic” (high level of broadband noise, lack
of a 27-day periodicity). The goal of this work is to search of the parameter of the solar activity dynamics
and/or the interplanetary medium which determines the switching of the magnetosphere regimes. We
used for the analysis series of daily values of the solar activity and interplanetary medium parameters
during the period of 1932 - 2016. It has been found that the dynamics of the spectral characteristics and
the trigger properties of the Ap and AL indices correlate with the dynamics of the solar wind parameter β
(β is ratio of the plasma pressure to magnetic pressure). It is shown that the change of the magnetosphere
regime “chaos - periodicity” is determined by the β value. The “chaotic” and “periodic” regimes in the
dynamics of the magnetosphere are observed at β≤1 and at β>1 respectively. We note that the level of
turbulent fluctuations in the solar wind reaches its maximum values precisely at β ~ 1 [1]. Consequently,
the ratio of the plasma pressure to magnetic pressure is the parameter that determines the switching
regime in the magnetosphere dynamics. The change of the β in the 11-year cycle of solar activity is
determined by the dynamics of the inclination angle of the magnetic dipole axis of the Sun [2, 3]. Thus,
the global geoeffective parameter determining the particular features of the dynamics of the
magnetosphere activity is the inclination angle of the magnetic dipole axis of the Sun to the ecliptic plane.
This work was supported by Russian Foundation for Basic Research 16-05-00056, Government task
0144-2014-00116.
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