m7.6 southern sumatra, indonesia, earthquake of 30 ... australia plate burma plate sunda plate...
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Map prepared by U.S. Geological SurveyNational Earthquake Information Center2 October 2009Map not approved for release by Director USGS
EARTHQUAKE SUMMARY MAP XXXU.S. DEPARTMENT OF THE INTERIORU.S. GEOLOGICAL SURVEY
DISCLAIMERBase map data, such as place names and politicalboundaries, are the best available but may not be current or may contain inaccuracies and thereforeshould not be regarded as having official significance.
Andaman Islands
ANDAMAN SEA
A n d a m a n B a s i n
Middle Andaman
South Andaman
Little Andaman
INDIACar Nicobar
S u m a t r a
J a v a
Siberut
Sipora
N PagaiS Pagai
Enggano
PiniNias
Tanahbala
I N D O N E S I A
2004
1797
2005
1833
2000 Jakarta
MelakaNegeri Sembilan
Selangor Pahang
SumateraSelatan
Songkhla
TerengganuPerak KelantanPulau Pinang
KedahNarathiwatAndaman and Nicobar
IslandsYala
PerlisPattani
JawaTimurJawa Tengah
Jakarta RayaJawa Barat
Lampung
Johor
Sumatera Barat
Bengkulu
Kalimantan Barat
Jambi KalimantanTengah
Singapore
Sumatera Utara
Aceh
Sarawak
Riau
2005
2004
2004
2004
2007
2007
2007
2007
2008
2008
A'
A
Pontianak
Padang
Jambi
Bengkulu
Tanjungkarang-Telukbetung
AlorSetar
KuantanNew Port
YalaKotaBaharu
PinangBandaAceh
KualaTerengganu
Ipoh
Seremban
Melaka
KuchingJohorBaharu
PekanbaruSingapore
SemarangBandung
Palembang
KualaLumpur
Medan
Narathiwat
KemamanHarbor
PattaniSatun Kangar
KualaLipis
ShahAlam
1907
1913
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1916
1900
1984
20012000
1998
1983
1976
1975
1971
1969
19631957
1955
19501949
1909
1946
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19431943
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19361935
1935
193319311931
1917
110°
110°
108°
108°
106°
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104°
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102°
100°
100°
98°
98°
96°
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92°
92°
6° 6°
4° 4°
2° 2°
0° 0°
2° 2°
4° 4°
6° 6°
PALAWAN
TROUGH
SU NDA (J AVA) T RENCH
AUSTRALIA PLATE
BURMAPLATE
SUNDA PLATE
MOLUCCASEA
PLATE
BANDA SEAPLATE
AUSTRALIAPLATE
S O U T HC H I N A
S E A
J A VA S E A
A N D A M A NS E A
B A Y O FB E N G A L
BorneoSumatra
Java Lesser Sunda IslandsGreater Sunda Is lands
S u m a t r a F a u l t
P h i l i p p i n eF a u l t
I N D O N E S I A
S R I L A N K A
T H A I L A N D
S I N G A P O R E
MA L A Y S I A
C A M B O D I AV I E T N A M
P H I L I P P I N E S
B R U N E I
M A L A Y S I A
Gulfof
Thailand
M i d - I n d i a nB a s i n
N o r t hA u s t r a l i a n
B a s i n
Ni n
et y
Ea
s t R
i dg
e
Investigat o r Ri d g e
O s b o r nP l a t e a u
C e l e b e sB a s i n
60 mm/yr
18332000
2005
2004
1797
120°
120°
110°
110°
100°
100°
90°
90°
10° 10°
0° 0°
10° 10°
M7.6 Southern Sumatra, Indonesia, Earthquake of 30 September 2009
0 220 440 660 880110Kilometers
INDONESIA
Palembang
Surabaya
QuezonCity
Manila
PhnomPenh
Davao
Medan KualaLumpur
Singapore
Makassar
Bandung Semarang
Darwin
QuangNgai
KuantanNew Port
NakhonSawan Ubon
Ratchathani
Pinang
NakhonRatchasimaSaraburiPhra Nakhon
Si AyutthayaTavoy Play CuQui NhonSamut PrakanSamutSakhon
SiemreabBatdambangBuon Me
Thuot NhaTrang
Da LatPortBlair
Bien HoaPhanThiet
LongXuyen My Tho
VinhLongCan ThoRach Gia
SocTrang
Bac LieuNakhon SiThammarat
SongkhlaYala Kota
BaharuAlor
Setar KotaKinabaluBanda
AcehKualaTerengganu
BandarSeri
BegawanIpoh
SerembanMelaka KuchingJohorBaharu Manado
PekanbaruPontianak SamarindaPadang BalikpapanJambi
PalangkarayaBandjermasin AmbonBengkulu Kendari
Tanjungkarang-Telukbetung
YogyakartaDiliMataram
Kupang
Jakarta
Bangkok
130°
130°
120°
120°
110°
110°
100°
100°
10° 10°
0° 0°
10° 10°
DATA SOURCESEARTHQUAKES AND SEISMIC HAZARD USGS, National Earthquake Information Center NOAA, National Geophysical Data Center IASPEI, Centennial Catalog (1900 - 1999) and extensions (Engdahl and Villaseñor, 2002) HDF (unpublished earthquake catalog) (Engdahl, 2003) Global Seismic Hazard Assessment ProgramPLATE TECTONICS AND FAULT MODEL PB2002 (Bird, 2003) Finite Fault Model, Chen Ji, UC Santa Barbara (2007)BASE MAP NIMA and ESRI, Digital Chart of the World USGS, EROS Data Center NOAA GEBCO and GLOBE Elevation Models
0 410 820 1,230 1,640205Kilometers
Prepared in cooperation
with the Global Seismographic
Network
Tectonic Setting
Seismic Hazard
Epicentral Region
Southern Sumatra 30 September 2009 10:16:09 UTC 0.788° S., 99.961° E.Depth 80 kmMw = 7.6 (USGS)45 km (30 miles) WNW of Padang, Sumatra, Indonesia220 km (135 miles) SW of Pekanbaru, Sumatra, Indonesia475 km (295 miles) SSW of KUALA LUMPUR, Malaysia
TECTONIC SUMMARYThe magnitude 7.6 southern Sumatra earthquake of September 30, 2009occurred as a result of oblique-thrust faulting near the subductioninterface plate boundary between the Australian and Sunda plates. At thelocation of this earthquake, the Australian Plate moves northeast withrespect to the Sunda plate at a velocity of approximately 60 mm/yr.On the basis of the currently available fault mechanism information andearthquake depth of 80 km, it is likely that this earthquake occurredwithin the subducting Australian Plate rather than on the plate interfaceitself. The recent earthquake was deeper than typical subduction thrustearthquakes that generally occur at depths less than 50 km.The subduction zone surrounding the immediate region of this event hasnot witnessed a megathrust earthquake in the recent past, rupturing lastin an earthquake of M 8.5 or larger in 1797. Approximately 350km tothe south, a 250km section of the plate boundary slipped during an Mw8.4 earthquake in September 2007, while approximately 300km to thenorth, a 350km section slipped during the Mw 8.7 earthquake of March2005. In early 2008, the plate boundary updip of today's earthquake wasactive in a sequence of Mw 5-6 earthquakes. It is not clear how today'searthquake is related to the sequence of megathrust subduction zoneevents on the shallower section of the plate boundary.
Seismic hazard is expressed as peakground acceleration (PGA) on firmrock, in meters/sec², expected to beexceeded in a 50-yr period with aprobability of 10 percent.
EXPLANATIONMag ≥ 7.0
0 - 69 km70 - 299300 - 600
Plate BoundariesSubductionTransformDivergentOthersAndaman FaultsRupture Area (Year)
RELATIVE PLATE MOTIONSIn the region of this earthquake,the Australia Plate movesnorth-northwest with respect tothe Sunda Plate at about 65 mm/yr.
0 410 820 1,230 1,640205Kilometers
REFERENCESBird, P., 2003, An updated digital model of plate boundaries: Geochem. Geophys. Geosyst., v. 4, no. 3, pp. 1027- 80.Engdahl, E.R. and Villaseñor, A., 2002, Global Seismicity: 1900 - 1999, chap. 41 of Lee, W.H.K., and others,eds., International Earthquake and Engineering Seismology, Part A: New York, N.Y., Elsevier Academeic Press, 932 p.Engdahl, E.R., Van der Hilst, R.D., and Buland, R.P., 1998, Global teleseismic earthquake relocation with improved trav- el times and procedures for depth determination: Bull. Seism. Soc. Amer., v. 88, p. 722-743.The GEBCO_08 Grid, version 20090202, http://www.gebco.net
Significant Earthquakes Mag >= 7.0
Year Mon Day Time Lat Long Dep Mag1900 01 05 1900 -3.000 102.000 0 7.01907 01 04 0519 2.000 94.500 50 7.51909 06 03 1840 -2.000 101.000 0 7.21913 08 13 0425 -5.500 105.000 75 7.31914 06 25 1907 -4.500 102.500 0 7.61916 07 27 1152 4.000 96.500 100 7.01917 11 04 1203 4.800 96.800 0 7.11931 02 10 0634 -5.433 102.458 35 7.11931 09 25 0559 -5.178 102.511 35 7.31933 06 24 2154 -5.522 104.434 35 7.31935 08 03 0110 4.430 96.326 35 7.01935 12 28 0235 -0.345 98.147 35 7.81936 01 02 2234 -0.279 98.872 35 7.01936 08 23 2112 5.296 94.759 35 7.11936 09 19 0101 3.648 97.551 35 7.11943 04 01 1418 -6.500 105.500 0 7.11943 06 08 2042 -1.000 101.000 50 7.21943 06 09 0306 -1.000 101.000 50 7.51943 11 26 2125 -2.500 100.000 130 7.11946 05 08 0520 0.000 99.500 0 7.11949 06 24 2238 -6.200 105.700 65 7.01950 03 27 2118 -5.900 102.900 0 7.01955 05 17 1449 6.738 93.754 29.1 7.21957 04 16 0404 -4.504 107.244 600 7.21963 12 15 1934 -4.764 108.050 668 7.11969 11 21 0205 1.973 94.574 11 7.61971 02 04 1533 0.552 98.665 60 7.11975 10 01 0330 -4.859 102.145 37.2 7.01976 06 20 2053 3.437 96.254 16.2 7.01983 04 04 0251 5.724 94.694 94.5 7.01984 11 17 0649 0.179 97.959 28.7 7.11998 04 01 1756 -0.544 99.217 32 7.02000 06 04 1628 -4.762 102.007 34.6 7.92001 02 13 1928 -4.933 102.454 34 7.32004 07 25 1435 -2.427 103.981 582 7.32004 12 26 0058 3.295 95.982 30 9.02004 12 26 0421 6.910 92.958 39 7.22005 03 28 1609 2.085 97.108 30 8.62007 08 08 1705 -5.859 107.419 280 7.52007 09 12 1110 -4.438 101.367 34 8.52007 09 12 2349 -2.625 100.841 35 7.92007 09 13 0335 -2.130 99.627 22 7.02008 02 20 0808 2.768 95.964 26 7.42008 02 25 0836 -2.486 99.972 25 7.2
Peak Ground Acceleration in m/sec**2
.2 .4 .8 1.6 2.4 3.2 4.0 4.8
EPICENTRAL REGION
EXPLANATIONMain Shock
M6.6 1 Oct 2009Earthquake Magnitude
5.50 - 5.996.00 - 6.997.00 - 7.998.00 - 8.99
9.00 - 9.99
Earthquake Depth0 - 6970 - 299300 - 700Sumatra Fault
EPICENTRAL REGION
Depth
(km)
Distance (km)A A' -300
-300
-200
-200
-100
-100
0
0
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100
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200
-300 -300
-200 -200
-100 -100
0 0
Southern Sumatra 1 October 2009 1:52:47 UTC -2.602° S., 101.702° E.Depth 10 kmMw = 6.6 (USGS) .
-300
-300
-200
-200
-100
-100
0
0
100
100
200
200
-300 -300
-200 -200
-100 -100
0 0