New Evidence of High-Temperature, High-Pressure Processes at the Site of the 1908 Tunguska Event: Implications for Impact and Airburst Phenomena

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F25%3A10499740" target="_blank" >RIV/00216208:11310/25:10499740 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=2HXFpm1ds5" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=2HXFpm1ds5</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.14293/ACI.2025.0001" target="_blank" >10.14293/ACI.2025.0001</a>

Result language

angličtina

Original language name

New Evidence of High-Temperature, High-Pressure Processes at the Site of the 1908 Tunguska Event: Implications for Impact and Airburst Phenomena

Original language description

We report diverse shock-metamorphosed and melted grains from the 1908 airburst site in Russia, one of history&apos;s most significant and enigmatic cosmic events. Analysis of samples from a rimmed crater-like feature near the epicenter using scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and cathodoluminescence (CL) revealed evidence of extreme conditions. Our findings indicate heterogeneous shock pressures (~&gt;=2 GPa) and temperatures (~&gt;=1710°C) produced various microparticles, including FeO and aluminosilicate glass microspherules, melted quartz microspherules, carbon spherules, glass-like carbon, and melted minerals. Notably, quartz grains exhibit high-temperature melting and shock metamorphism, including planar deformation features (PDFs) and planar fractures (PFs), with some showing glass-lined internal fractures and melted silica coatings. Similarly, some feldspar grains display melted feldspar coatings. While multiple origins for these materials are possible - including an older crater and volcanism - the evidence best supports the 1908 Tunguska airburst hypothesis. The abundance of melted, shocked materials in the biomass-burning layer aligns with proposals that airburst fragments struck the Earth&apos;s surface at velocities sufficient to produce shocked quartz. The coexistence of melted particles, shock-metamorphosed minerals, and unaltered grains suggests a heterogeneous energy distribution that created shallow craters and melted surface materials. These findings advance our understanding of airburst/impact mechanics, but few people have ever observed a dangerous airburst like Tunguska, so very little is known about them. Lacking sufficient real-world data, scientists should continue modeling these dangerous low-altitude airbursts to understand them better. The Tunguska event is a valuable case study demonstrating the urgent need to improve our planetary defense strategies.

Czech name

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Czech description

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Type

J_ost - Miscellaneous article in a specialist periodical

CEP classification

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OECD FORD branch

10505 - Geology

Project

<a href="/en/project/GA23-06075S" target="_blank" >GA23-06075S: Environmental changes caused by extraterrestrial impacts and volcanism: Evidence from lake sediments</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Airbursts and Cratering Impacts

ISSN

2941-9085

e-ISSN

2941-9085

Volume of the periodical

3

Issue of the periodical within the volume

1

Country of publishing house

DE - GERMANY

Number of pages

26

Pages from-to

e20250001

UT code for WoS article

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EID of the result in the Scopus database

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