September 20, 2012
Did The Eltanin Meteor Cause More Than Tsunamis?
April Flowers for redOrbit.com - Your Universe Online
Around 2.5 million years ago, a huge meteor collided with the Earth and fell into the southern Pacific Ocean. A new study, published in the Journal of Quaternary Science, suggests that not only could this have caused a massive tsunami, but it may also have plunged the world into the Ice Ages.
A research team from Australia says that because the Eltanin meteor — which was up to two kilometers across — crashed into deep water, the potential for immediate catastrophic impacts on coastlines around the Pacific Rim or the meteor's capacity to destabilize the entire planet's climate system has largely been ignored by the scientific community.
“This is the only known deep-ocean impact event on the planet and it´s largely been forgotten because there´s no obvious giant crater to investigate, as there would have been if it had hit a landmass,” says Professor James Goff, co-director of UNSW´s Australia-Pacific Tsunami Research Centre and Natural Hazards Research Laboratory.
“But consider that we´re talking about something the size of a small mountain crashing at very high speed into very deep ocean, between Chile and Antarctica. Unlike a land impact, where the energy of the collision is largely absorbed locally, this would have generated an incredible splash with waves literally hundreds of meters high near the impact site."
“Some modeling suggests that the ensuing mega-tsunami could have been unimaginably large — sweeping across vast areas of the Pacific and engulfing coastlines far inland. But it also would have ejected massive amounts of water vapor, sulfur and dust up into the stratosphere."
“The tsunami alone would have been devastating enough in the short term, but all that material shot so high into the atmosphere could have been enough to dim the sun and dramatically reduce surface temperatures. Earth was already in a gradual cooling phase, so this might have been enough to rapidly accelerate and accentuate the process and kick start the Ice Ages.”
Goff and colleagues from UNSW and the Australian Nuclear Science and Technology Organization note that geologists and climatologists have interpreted geological deposits in Chile, Antarctica, Australia, and elsewhere as evidence of climatic change. This marked the beginning of the Quaternary period, the most recent period of the Cenozoic Era. This period is characterized by a series of glaciations and the appearance and spread of modern humans.
Alternatively, the study suggests that some or all of these deposits could be the result of mega-tsunami inundation.
“There´s no doubt the world was already cooling through the mid and late Pliocene,” says co-author Professor Mike Archer. “What we´re suggesting is that the Eltanin impact may have rammed this slow-moving change forward in an instant - hurtling the world into the cycle of glaciations that characterized the next 2.5 million years and triggered our own evolution as a species."
“As a ℠cene´ changer - that is, from the Pliocene to Pleistocene - Eltanin may have been overall as significant as the meteor that took out the non-flying dinosaurs 65 million years ago. We´re urging our colleagues to carefully reconsider conventional interpretations of the sediments we´re flagging and consider whether these could be instead the result of a mega-tsunami triggered by a meteor.”