|20 December 2004
Ancient flood may have triggered Intra-Allerod Cold Period
Scientists in America have uncovered evidence that the Intra-Allerod Cold Period was started by a massive catastrophic flood on the US-Canadian border a3,350 years ago.
Glacial Lake Iroquois, which was in the same location as modern day Lake Ontario but three times the size, was formed as the Laurentide Ice Sheet receded about 21,000 to 13,000 years ago from its maximum extent along southern Long Island, New York, and northern New Jersey to southern Canada.
After studying data from sediment cores, walrus fossils and pollen, the scientists from Woods Hole Oceanographic Institution in Massachusetts believe a natural dam north of the Adirondack Mountains in upstate New York collapsed, allowing water from Lake Iroquois to drain into the Hudson River Valley and down into the North Atlantic, dropping the level of the lake by 120 meters.
The sudden flood of glacial freshwater into the Atlantic would have altered the thermohaline circulation in the ocean, and therefore impacted on the climate, causing the Intra-Allerod Cold Period which lasted about 150 years, just before the Younger Dryas, a sudden cold period lasting around 1,200 years and ending about 11,000 years ago.
The complete results will be published in February 2005 in the journal Geology.
Source: newswise (16 December 2004)
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