Tunguska (1908) and Its Relevance for Comet/Asteroid Impact Statistics [chapter]

Wolfgang Kundt
Comet/Asteroid Impacts and Human Society  
During the 1908 Tunguska catastrophe, trees were flattened over an area of more than 2000 Km 2 of Siberian taiga. For several decades, this destruction was thought to be caused by the impact of a sizable meteorite, some 60 m across, and served as a well-defined data point on the terrestrial impact spectrum (i.e. impact rate versus destruction energy). But doubts in the impact interpretation emerged, via a continued absence of detected impact grains, via controversies between the cometary and
more » ... the cometary and asteroidal proponents, via the net-zero-momentum treefall pattern with its multiple centers, the three European bright nights (illuminated by scattered sunlight), details of the eyewitness reports, and the geologically preferred site of the destruction, in the Kulikovskii volcanic crater with its intersecting fault lines. In this report, I shall analyze the Tunguska event, compare it with several similar catastrophes, and present more than a dozen criteria that can serve to discriminate between a meteoritic impact and a tectonic outburst (of the kimberlite type). Tectonic outbursts turn out to be (likewise) powerlaw distributed (as a function of destruction energy), with practically the same spectral slope as the asteroidal impacts, but are more frequent than the latter by a factor of at least 20. ___________________________________________________________________________
doi:10.1007/978-3-540-32711-0_19 fatcat:p5qmz4xqrfaahh7sgbasoleo6a