Search for the Tunguska event in the Antarctic snow
The Tunguska explosion in 1908 is supposed to have been produced by the impact of a small celestial body. The absence of any identifiable crater together with the huge energy released by the event suggest that the impactor exploded in midair and that its material was widely spread over the Earth. Th...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19890012007 2023-05-15T13:35:10+02:00 Search for the Tunguska event in the Antarctic snow Bonte, PH. Deangelis, M. Robin, E. Rocchia, R. Jehanno, C. Doclet, D. Unclassified, Unlimited, Publicly available JAN 1, 1988 application/pdf http://hdl.handle.net/2060/19890012007 unknown Document ID: 19890012007 Accession ID: 89N21378 http://hdl.handle.net/2060/19890012007 No Copyright CASI GEOPHYSICS Lunar and Planetary Inst., Global Catastrophes in Earth History: An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality; p 156-157 1988 ftnasantrs 2015-03-15T05:57:04Z The Tunguska explosion in 1908 is supposed to have been produced by the impact of a small celestial body. The absence of any identifiable crater together with the huge energy released by the event suggest that the impactor exploded in midair and that its material was widely spread over the Earth. The short term contribution of such exceptional events to the total accretion rate of extraterrestrial material by the Earth could be significant. Samples were chosen in a core electromechanically drilled in 1984 near South Pole Station. There, the low temperatures, preventing melting all year long, and the nearly regular snow fall rate provide good conditions for a reliable continuous record of any infalling material. In many samples Ir was below the detection limit of the instrumentation. The iridium infall averaged over 45 samples is given. In a few samples the iridium content is significantly higher than the average: the frequency and amplitude of such fluctuations can be explained by the presence on some filters of finite size cosmic particles. No significant systematic increase above the average level is observed in the part of the core corresponding to the Tunguska event. The two major results of this study are: (1) The presence of Tunguska explosion debris in the Antarctic snow is not confirmed; and (2) The estimate of the average iridium infall, is an order of magnitude lower than the Ganapathy's background but is close to the values measured in Antarctic snow and atmospheric samples by Takahashi et al. The results are also consistent with the flux of micrometeoroids deduced from optical and radar observations or derived from the study of Greenland cosmic dust collection but are lower than the flux at mid-latitude measured in paleocene-oligocene sediments from the central part of the Pacific Ocean. Other/Unknown Material Antarc* Antarctic Greenland South pole South pole NASA Technical Reports Server (NTRS) Antarctic The Antarctic Greenland Pacific South Pole Tunguska ENVELOPE(144.784,144.784,59.388,59.388) |
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Open Polar |
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NASA Technical Reports Server (NTRS) |
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ftnasantrs |
language |
unknown |
topic |
GEOPHYSICS |
spellingShingle |
GEOPHYSICS Bonte, PH. Deangelis, M. Robin, E. Rocchia, R. Jehanno, C. Doclet, D. Search for the Tunguska event in the Antarctic snow |
topic_facet |
GEOPHYSICS |
description |
The Tunguska explosion in 1908 is supposed to have been produced by the impact of a small celestial body. The absence of any identifiable crater together with the huge energy released by the event suggest that the impactor exploded in midair and that its material was widely spread over the Earth. The short term contribution of such exceptional events to the total accretion rate of extraterrestrial material by the Earth could be significant. Samples were chosen in a core electromechanically drilled in 1984 near South Pole Station. There, the low temperatures, preventing melting all year long, and the nearly regular snow fall rate provide good conditions for a reliable continuous record of any infalling material. In many samples Ir was below the detection limit of the instrumentation. The iridium infall averaged over 45 samples is given. In a few samples the iridium content is significantly higher than the average: the frequency and amplitude of such fluctuations can be explained by the presence on some filters of finite size cosmic particles. No significant systematic increase above the average level is observed in the part of the core corresponding to the Tunguska event. The two major results of this study are: (1) The presence of Tunguska explosion debris in the Antarctic snow is not confirmed; and (2) The estimate of the average iridium infall, is an order of magnitude lower than the Ganapathy's background but is close to the values measured in Antarctic snow and atmospheric samples by Takahashi et al. The results are also consistent with the flux of micrometeoroids deduced from optical and radar observations or derived from the study of Greenland cosmic dust collection but are lower than the flux at mid-latitude measured in paleocene-oligocene sediments from the central part of the Pacific Ocean. |
format |
Other/Unknown Material |
author |
Bonte, PH. Deangelis, M. Robin, E. Rocchia, R. Jehanno, C. Doclet, D. |
author_facet |
Bonte, PH. Deangelis, M. Robin, E. Rocchia, R. Jehanno, C. Doclet, D. |
author_sort |
Bonte, PH. |
title |
Search for the Tunguska event in the Antarctic snow |
title_short |
Search for the Tunguska event in the Antarctic snow |
title_full |
Search for the Tunguska event in the Antarctic snow |
title_fullStr |
Search for the Tunguska event in the Antarctic snow |
title_full_unstemmed |
Search for the Tunguska event in the Antarctic snow |
title_sort |
search for the tunguska event in the antarctic snow |
publishDate |
1988 |
url |
http://hdl.handle.net/2060/19890012007 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(144.784,144.784,59.388,59.388) |
geographic |
Antarctic The Antarctic Greenland Pacific South Pole Tunguska |
geographic_facet |
Antarctic The Antarctic Greenland Pacific South Pole Tunguska |
genre |
Antarc* Antarctic Greenland South pole South pole |
genre_facet |
Antarc* Antarctic Greenland South pole South pole |
op_source |
CASI |
op_relation |
Document ID: 19890012007 Accession ID: 89N21378 http://hdl.handle.net/2060/19890012007 |
op_rights |
No Copyright |
_version_ |
1766061892939284480 |