T10 Teaching Media Literacy in the Geological Sciences
Sunday, 22 September 2024
8:00 AM - 12:00 PM
208B
MYTHS AND MISINFORMATION ABOUT TUNGUSKA AND COSMIC AIRBURSTS
Paper number: T10-10
Program: Technical Sessions
Time: 10:20 AM – 10:35 AM
Authors
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David MorrisonNASA Ames Research Center (retired), Mountain View, CA
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Olga PopovaInstitute of Geosphere Dynamics, Moscow
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Darrel RobertsonNASA Ames Research Center, Mountain View, CA
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Elizabeth A. SilberSandia National Laboratories, Albuquerque, NM
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Matthias Van GinnekenUniversity of Kent, Canterbury
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Peter BrownUniversity of Western Ontario, London, ON
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Andy BrunoNorthern Illinois University, DeKalb, IL
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Paul ChodasJet Propulsion Laboratory, Pasadena, CA
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Gareth S. CollinsImperial College London, London
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Tyrone DaultonWashington University in St. Louis, St. Louis, MO
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Alan HarrisJet Propulsion Laboratory (retired), Pasadena, CA
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Christian KoeberlUniversity of Vienna, Vienna
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Ania LosiakPolish Academy of Sciences, Warsaw
Abstract
If the Tunguska object had arrived 4 hours, 47 minutes later, it would have destroyed St. Petersburg. False. This assumes a geocentric orbit in which only Earth’s rotation matters. In reality, Earth’s motion around the sun would have caused it to miss by a half million km.
The Tunguska explosion flattened more than 80 million trees. False. This is based on a preliminary estimate of the tree fall area before the first aerial survey showed that it was much smaller. It is probably a factor of four too high
The vapor jet from a Tunguska-sized airburst expands radially outward at the surface as a base surge. False. A base surge is a density-driven flow. An airburst jet is buoyant and driven by inertia. After its downward momentum is depleted, it rises back into the sky
The Tunguska airburst melted surface materials and deposited diamonds, shocked quartz, and iridium. False. No shocked or impact-fractured quartz has ever been found that was caused by the Tunguska event because shock pressures were six orders of magnitude too low. The air shock at the surface and thermal radiation were not hot enough to melt anything.
The “Tunguska crater” image. Internet stories about Tunguska often use a photograph of a circular feature, implying that it was created by the event. It was not. The same image has been used in stories about “чертово кладбище” which is widely associated with Russian conspiracy theories and pseudoscientific speculation. Various locations have been claimed, including a clearing at (58°13'53"N, 100°15'32"E), about 300 km south of the Tunguska epicenter.
We will continue to add to our list of examples.
Geological Society of America Abstracts with Programs. Vol. 56, No. 5
doi: 10.1130/abs/2024AM-401469
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