News Release

Tunguska catastrophe: Evidence of acid rain supports meteorite theory

Peer-Reviewed Publication

Helmholtz Association

Tunguska-2

image: Evgeniy Kolesnikov photographed the same place 60 years later. The fallen trunks are still there, with the taiga growing in between them. view more 

Credit: Photo: Evgeniy M. Kolesnikov, Lomonosov Moscow State University

This release is available in German.

Moscow/Bologna/Halle. The Tunguska catastrophe in 1908 evidently led to high levels of acid rain. This is the conclusion reached by Russian, Italian and German researchers based on the results of analyses of peat profiles taken from the disaster region. In peat samples corresponded to 1908 permafrost boundary they found significantly higher levels of the heavy nitrogen and carbon isotopes 15N and 13C. The highest accumulation levels were measured in the areas at the epicentre of the explosion and along the trajectory of the cosmic body. Increased concentrations of iridium and nitrogen in the relevant peat layers support the theory that the isotope effects discovered are a consequence of the Tunguska catastrophe and are partly of cosmic origin. It is estimated that around 200,000 tons of nitrogen rained down on the Tunguska region in Siberia at that time. "Extremely high temperatures occurred as the meteorite entered the atmosphere, during which the oxygen in the atmosphere reacted with nitrogen causing a build up of nitrogen oxides," Natalia Kolesnikova told the Russian news agency RIA Novosti on last Monday. Mrs. Kolesnolova is one of the authors of a study by Lomonosov Moscow State University, the University of Bologna and the Helmholtz Centre for Environmental Research (UFZ), which was published in the journal Icarus in 2003.

The Tunguska event is regarded as one of the biggest natural disasters of modern times. On 30 June 1908 one or more explosions took place in the area close to the Tunguska River north of Lake Baikal. The explosion(s) flattened around 80 million trees over an area of more than 2000 square kilometres. The strength of the explosion is estimated to have been equivalent to between five and 30 megatons of TNT. That is more than a thousand times as powerful as the Hiroshima bomb. This almost unpopulated region of Siberia was first studied in 1927 by Professor Leonid A. Kulik. There are a number of different theories about what caused the catastrophe. However, the majority of scientists assume that it was caused by a cosmic event, such as the impact of a meteorite, asteroid or comet. If it had exploded in the atmosphere just under five hours later, St. Petersburg, which was the capital of Russia at that time, would have been completely destroyed because of the Earth's rotation.

In two expeditions in 1998 and 1999, Russian and Italian researchers took peat profiles from various locations within the Siberian disaster area. The type of moss studied, Sphagnum fuscum, is very common in the peat material and obtains its mineral nutrients exclusively from atmospheric aerosols, which means that it can store terrestrial and extraterrestrial dust. Afterwards, the samples were analysed in laboratories at the University of Bologna and the Helmholtz Centre for Environmental Research (UFZ) in Halle/Saale. Among other things, the UFZ specialises in isotope analyses of sediments, plants, soil and water and it was asked to help by the team of Moscow researchers led by Dr Evgeniy M. Kolesnikov. Kolesnikov, who has been investigating the Tunguska event for 20 years, has been to Leipzig University and UFZ twice as a guest researcher with the help of the German Research Foundation (DFG) to consult with the isotope experts. "The levels of accumulation of the heavy carbon isotope 13C measured right on the 1908 permafrost boundary in several peat profiles from the disaster area cannot be explained by any terrestrial process. This suggests that the Tunguska catastrophe had a cosmic explanation and that we have found evidence of this material," explains Dr Tatjana Böttger of the UFZ. Possible causes would be a C-type asteroid like 253 Mathilde, or a comet like Borelly.

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Publications:

KOLESNIKOV, E.M. LONGO, G., BOETTGER, T., KOLESNIKOVA N.V., GIOACCHINI, P., FORLANI, L., GIAMPERI, R., SERRA, R. (2003). "Isotopic-geochemical study of nitrogen and carbon in peat from the Tunguska Cosmic Body explosion site". Icarus 161 (2): 235-243.

(ICARUS is the official publication of the Division for Planetary Sciences of the American Astronomical Society.)

KOLESNIKOV, E.M., STEPANOV, A.I., GORIDKO, E.A., BÖTTGER,T., KOLESNIKOVA, N.V. (2000). Isotopic and elemental anomalies in peat from the Tunguska Cosmic Body explosion epicentre are the probable traces of cosmic material presence. - In: Special issue "90 anniversary of Tunguska meteorite", ed. Romeiko, B.A., Moscow, MGDTDJ-Department of astronomy and astronautics, 43-49

KOLESNIKOV, E. M., BÖTTGER, T., KOLESNIKOVA, N. V. (1999). Finding of probable Tunguska Cosmic Body material: isotopic anomalies of carbon and hydrogen in peat. - Planetary and Space Science 47, 6-7, 905-916

Further Informations:

Dr Tatjana Böttger
Helmholtz Centre for Environmental Research (UFZ)
Phone: +49-345-558-5314 http://www.ufz.de/index.php?de=697 und

Evgeniy M. Kolesnikov, Natalya V. Kolesnikova
Faculty of Geology, Moscow State University, 119992 Moscow, Russia
Phone: +007-95-932-4916
Fax: +007-95-932-8889

http://www.geol.msu.ru/deps/geochems/rus/Peop.html
http://www.geol.msu.ru/deps/geochems/rus/peop/Kolesnikov.html
http://www.geol.msu.ru/deps/geochems/rus/peop/kolesna.html

Links:

Acid rain traces support meteor theory for 1908 Tunguska blast
http://en.rian.ru/science/20080630/112598958.html

Climatic archives – learning for the future from the past (page 120+)
http://www.ufz.de/data/magazin_engl_web28815.pdf

At the Helmholtz Centre for Environmental Research (UFZ) scientists research the causes and consequences of far-reaching environmental changes. They study water resources, biological diversity, the consequences of climate change and adaptation possibilities, environmental and biotechnologies, bio energy, the behaviour of chemicals in the environment and their effect on health, as well as modelling and social science issues. Their guiding research principle is supporting the sustainable use of natural resources and helping to secure these basic requirements of life over the long term under the influence of global change. The UFZ employs 900 people at its sites in Leipzig, Halle and Magdeburg. It is funded by the German government and by the states of Saxony and Saxony-Anhalt.

The Helmholtz Association helps solve major, pressing challenges facing society, science and the economy with top scientific achievements in six research areas: Energy, Earth and Environment, Health, Key Technologies, Structure of Matter, Transport and Space. With 25,700 employees in 15 research centres and an annual budget of around EUR 2.3 billion, the Helmholtz Association is Germany's largest scientific organisation. Its work follows in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894).


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