Siberian forest after explosion of the Siberian forest after explosion of the Tunguska body: astroecological Tunguska body: astroecological

problemsproblems

E.A. KasatkinaE.A. Kasatkina and and O.I. Shumilov O.I. Shumilov

Institute of North Industrial Ecology Problems of Institute of North Industrial Ecology Problems of Kola Science Centre RAS, Apatity, RUSSIA; e-mail: Kola Science Centre RAS, Apatity, RUSSIA; e-mail:

oleg@aprec.ruoleg@aprec.ru

We analyzed tree rings in larch samples collected in the Taymir region ofNorthern Siberia (72N; 105E) at a distance of about 1500 km to the Northfrom the Tunguska catastrophe epicenter (61N; 102E). It was found thattree ring growth is 150% higher in 1908. We also analyzed all availableSiberian tree-ring series (more than 100). It was found that there is aconsiderable increase of tree ring growth in 1908 over a huge area ofSiberia (60N-75N; 60E-110E). Most likely the tree growth was stimulatedby the TO matter spreaded over a large territory of Eurasia and introducedinto the soil. It is generally believed that meteorites and comets deliveredlarge amounts of organic to the early Earth. Another hypothesis isconnected to NO produced during the Tunguska event. It is interestingthat we've discovered nearly the similar, but smaller (about 40%) increaseof tree ring growth connected to the Chulym bolide impact in 1984. TheChulym bolide exploded above the Chulym river, Siberia (57.7N; 85.1E) on26 February, 1984. The TNT equivalent of Chulym explosion was 10 Kt,that is rather less than the TNT equivalent of the Tunguska explosion (10-40 Mt). The results of analysis showed that tree-rings can be used todetect impacts of Tunguska-sized and smaller bodies meters to tens ofmeters in size.

Environmental consequences of impacts by comets and asteroids depend on their sizes. The impact of 10 km sized asteroid killed off the dinosaurs 65 million years ago. A comet impact in AD 536 (>500 m diameter) caused a global climatic downturn. An impact of Tunguska-sized (50 m diameter) object could devastate a 2000 km^2 forest area, roughly the size of Moscow or New York.

Scientists think impacts from comets may have played a role in the evolution of Earth billions of years ago. Meteorites and comets delivered largeamounts of organic to the early Earth.

A comet impact in AD 536?A comet impact in AD 536?(E. Rigby, M. Symonds,

D. Ward-Thompson, 2004)

Dendrochronological data showing the decreases in therate of tree-ring growth for the years around AD 540.

USAIreland

Comet or Asteroid?Comet or Asteroid? On June 30, 1908, something exploded On June 30, 1908, something exploded

above the Siberian taiga, near the above the Siberian taiga, near the Tunguska River. The TNT equivalent of Tunguska River. The TNT equivalent of explosion is estimated between 10 and explosion is estimated between 10 and 40 megatons. The explosion 40 megatons. The explosion devastated a 2000 kmdevastated a 2000 km22 forest area. forest area.

Theories of its origin range from a Theories of its origin range from a large asteroid or comet, to a nuclear-large asteroid or comet, to a nuclear-fueled spaceship.fueled spaceship.

Some mSome myysteries of steries of Tunguska eventTunguska event

The mechanism of optical The mechanism of optical anomalies (abnormal dawns and anomalies (abnormal dawns and luminescence of an atmosphere) luminescence of an atmosphere) developed in the summer of 1908 developed in the summer of 1908 before and after Tunguska event.before and after Tunguska event.

The cause of the accelerated tree The cause of the accelerated tree growth after 1908 in the growth after 1908 in the catastrophe area.catastrophe area.

Development of optical anomalies in summer of 1908. Total number of points where optical anomalies were registered - solid line (I), number of points where noctilucent clouds were observed - dashed line (II). The appearance of noctilucent clouds during June-July 1908 must have been the largest event of that type in the last century (Vasilyev, 1998).

Points where optical anomalies of summer 1908 were observed. Anomalies observed to the west from the place of explosion (West Siberia,European Russia, Northern Europe) but not seen in other parts of the Earth.

+

Calculations by Zotkin in 1969and Kresak in 1978 have shown that TSB was a fragment bycomet Enke. This version makesclear why 10 days prior toTunguska event in NorthernHemisphere were registeredoptical anomalies. It was an influence of the ionized dust tailof a comet on the top layers of the Earth’s atmosphere.And the more the trajectory offlight TSB came nearer to the Earth after June 20, the scalesof this influence were stronger.

Note: The similar optical phenomena were observed in the sky of the Earth when theEarth passed through a tail of Galley comet.Note: The appearance of dust before the passage of fireball was observed during thesimilar event - “1930 Brazilian Event”. It was called “Brazilian twin” of Tunguskaevent (Bailey et al., 1995).

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Cita (52.1N ; 113.5E)

Small increase in summer temperatureswould hardly be a mainreason of the acceleratedtree growth observed.

Areas where accelerated tree growth was observed: zone A -112%; zone B - 70%. Accelerated tree growth was observed12° to the north, 10° to the east and 20° to the west from theplace of explosion.

Winter

Summer

Zonal winds inthe NorthernHemisphere

Consequences of the Chulym bolideConsequences of the Chulym bolideexplosion and tree growthexplosion and tree growth

The Chulym bolide exploded above theChulym river, Siberia (57.7N; 85.1E) on 26 February, 1984.TNT equivalent - 10 Kt

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55-75N; 80-90E- 63%

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Areas where accelerated tree growth was observed: zone A -63%; zone B - 50%. Accelerated tree growth was observed14° to the north, 5° to the west and 15° to the east from theplace of explosion.

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)Tom sk (56.5N ; 84.9E)

Kolpasevo (58.3N ; 83E)

Barnaul (53.4N ; 83.5E)

ChulymSummer temperatures

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1866 1870 1874 1878 1882Years

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rin

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idthKhibini m ountains (67.8N; 33.7E)

Khibini m ountains (67.8N; 33.6E)

Lovozero (68N ; 35E)

Apatity (67.6N; 33.5E)

Consequences ofConsequences ofthe Kola bolidethe Kola bolideexplosion (1873)explosion (1873)and tree growth.and tree growth.

49%

29%

26%

Possible reasons of the Possible reasons of the tree-growth anomaly tree-growth anomaly

observedobserved

Stimulation of tree growth by Stimulation of tree growth by cometary matter spreaded over a cometary matter spreaded over a large territory and introduced into large territory and introduced into a soil.a soil.

NO produced in the atmosphere NO produced in the atmosphere during bolide explosions: Tunguska during bolide explosions: Tunguska event - 30 million tons event - 30 million tons (Turko et al., (Turko et al., 1982);1982); Chulym bolide - 7000 tons. Chulym bolide - 7000 tons.

The comet compositionThe comet composition

1. Organic - C, C1. Organic - C, C22, CN, CO, HCN et , CN, CO, HCN et al.;al.;

2. Inorganic - H, NH, NH2. Inorganic - H, NH, NH22, O, OH, , O, OH, HH22O;O;

3. Metals - Na, Ca, Cr, Mn, Fe, Cu et 3. Metals - Na, Ca, Cr, Mn, Fe, Cu et al.;al.;

4. Ions - CO4. Ions - CO++, CN, CN++, OH, OH++, H, H22OO++ et al. et al.

Effects on plant growth were examined on Solanumtuberosum (potato), where extracts of the Murchisonmeteorite lead to enhanced growth and pigmentation.

ConclusionsConclusions

It was considered the possibility of It was considered the possibility of using of tree-ring chronologies as a using of tree-ring chronologies as a proxy of comet impacts.proxy of comet impacts.