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Friday, June 20, 2008

Sharp warm spikes at the end of the Ice Age.

A University of Colorado team researching the Greenland ice sheet has found that two sudden warm epysodes happened just before the definitive end of the Ice Age some 10,000 years ago.

The first one was c. 14,700 BP and lasted till c. 12,900 BP. Then deep freeze conditions were back agains for some 1200 years until the second sudden warming (11,700 BP) that preluded the definitive end of the Ice Age.

But the most important finding is that the warming happened in such a brief period as 50 years, with the reorganization of atmospheric circulation being as quick as only one or two years!

We have analyzed the transition from the last glacial period until our present warm interglacial period, and the climate shifts are happening suddenly, as if someone had pushed a button.

The origin of the sudden changes seems to be in the tropical belt but it doesn't seem like the researchers can pinpoint the ultimate trigger of such a climatic change.

While these abrupt climate changes could really alter radically the life of Paleolithic hunter-gatherers, for the case of Europe, the first one seems to imply some continuity: Magdalenian was dominant in the SW and expanded to Central Europe about that date. The second one preludes the Paleolithic, with the gradual diversification of Magdalenian culture but it doesn't show lack of continuity either. Fully diversified Epipaleolithic cultures (Azilian, Sauveterrean, etc.) are only found since c. 10,000 BP, some time after the second peak, when the Ice Age had already become history.

(Via Science Daily)


Anonymous said...
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Maju said...

Anonymous wrote:

Feel free to delete this, since it is intended to be nothing but insulting.

Sure. That's what the trash can icon is for. We don't need nazis here anyhow.