North American Comet Catastrophe 10,900 BC
October 31, 2007 10:54 AM Subscribe
posted by stbalbach (23 comments total)
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On May 23, 2007 a multi-disciplinary team of scientists announced (YouTube, 70mins, 7-parts, part1-1 is a summary)
the finding of physical evidence strongly suggesting that, around 12,900 years ago (10,900 BC), a massive Shoemaker-Levy type comet hit the atmosphere, air burst over the Great Lakes region of North America and probably engulfed much of the continent in a fireball and subsequent firestorm with catastrophic effects for life and climate.
The extraterrestrial event coincides with the mass extinction or depopulation of many of North America's largest mammals
(including camels, mammoths, the short-faced bear and numerous other species); coincides with the end of the Clovis culture
; and coincides with the start of a global climatic shift known as the Younger Dryas, a sudden return of Ice Age conditions. The "Younger Dryas impact event"
, as it is banally being called, now competes with some well known and hotly debated theories, such as human hunters killed the mammals; or the Younger Dryas was caused by a slow down in the Gulf Stream (which has implications for current Global Warming predictions). On September 27, 2007 the team officially published their findings as "Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling" (PNAS open access)