Massive flood that caused ancient 'Big Freeze' located
A giant flood of Arctic melt-water may have triggered an ancient 1,200-year-long chill nicknamed the "Big Freeze," the last major cold age on Earth, a new study finds. These findings suggest that changes in the flow of water in the Arctic could suddenly alter the modern climate, study investigators added. Starting about 12,900 years ago, the Northern Hemisphere was abruptly gripped by centuries of cold, an era technically known as the Younger Dryas. Scientists have suggested this chill helped wipe out most of the large mammals in North America as well as the so-called Clovis people. The Big Freeze was not a glacial period, which are colloquially often called ice ages - it was a cold time in the relatively warm spans between glacial periods. Read more
Title: Seasonal Laurentide Ice Sheet melting during the "Mystery Interval" (17.5-14.5 ka) Authors: Carlie Williams, Benjamin P. Flower and David W. Hastings
The last deglaciation in the Northern Hemisphere was interrupted by two major stadials, the so-called "Mystery Interval" (17.5-14.5 ka) and the Younger Dryas (12.9-11.7 ka). During these events, the North Atlantic region was marked by cold surface conditions, yet simultaneous glacier and snowline retreat. Rerouting of Laurentide Ice Sheet melt-water from the Gulf of Mexico to an eastern or northern spillway may have reduced meridional overturning circulation at the onset of the Younger Dryas.
The cause of rapid sea level rise in the past has been found by scientists at the University of Bristol using climate and ice sheet models. The process, named 'saddle-collapse', was found to be the cause of two rapid sea level rise events: the Melt water pulse 1a (MWP1a) around 14,600 years ago and the 8,200 year event. The research is published today in Nature. Read more
Not long ago, geologically speaking, a now-vanished lake covered a huge expanse of today's Canadian prairie. As big as Hudson Bay, the lake was fed by melting glaciers as they receded at the end of the last ice age. At its largest, Glacial Lake Agassiz, as it is known, covered most of the Canadian province of Manitoba, plus a good part of western Ontario. A southern arm straddled the Minnesota-North Dakota border. Not far from the ancient shore of Lake Agassiz, University of Cincinnati Professor of Geology Thomas Lowell will present a paper about the lake to the Geological Society of America annual meeting in Minneapolis. Read more
A team of archaeologists from British universities are due to return to Jersey to start their second season excavating across the island. Over the course of a month they will investigate a late ice age hunting camp in St Saviours, trace buried ice age coastlines and use sonar to map ancient landscapes submerged beneath the seas off the island's coast. The work will take place between 3rd and 22nd July by a team drawn from UCL's Institute of Archaeology, Southampton University, Manchester University and University of Wales Trinity St Davids . The project forms part of the Leverhulme-funded Ancient Human Occupation of Britain (AHOB) project based at the British Museum and has been developed in close partnership with Société Jersiaise and Jersey Heritage. Read more
A British astronomer has published new evidence that North America was strafed by thousands of fragments from a massive comet about 12,900 years ago, a theory he says is the best explanation yet for why the planet was plunged into a 1,000-year cooling period and dozens of ice age mammals went extinct at that time.
A thousand years after the last ice age ended, the Northern Hemisphere was plunged back into glacial conditions. For 20 years, scientists have blamed a vast flood of melt-water for causing this 'Younger Dryas' cooling, 13,000 years ago. Picking through evidence from Canada's Mackenzie River, geologists now believe they have found traces of this flood, revealing that cold water from North America's dwindling ice sheet poured into the Arctic Ocean, from where it ultimately disrupted climate-warming currents in the Atlantic. Read more
There was a time when the river we celebrate this year did not exist. A time eons before an English sea captain discovered what had been there since human beings could remember. A time before human beings existed. You could call that pre-history if you like. But not if you know how to read the signs, which are abounding. Alex Bartholomew, a professor of geology specializing in stratigraphy and palaeontology at SUNY New Paltz, has only to look around to read the history of the river. It's a history written in stone, in the rocks and the rock formations that have been shaped, exposed, buried, sunken and carved by all the wind, water, air and tectonic upheaval that 1.4 billion years can contain.
Two Canadian scientists probing the depths of Hudson Bay have discovered deep gouges on the sea floor and other evidence shedding new light on a colossal flood that occurred more than 8,000 years ago - a time when retreating glaciers were clearing a path for the first human populations in central Canada. Read more
A release of fresh water from a huge glacial lake in Canada triggered the most dramatic spell of chill in Europe and North America some 8200 years ago, according to a new study. The burst in Lake Agassiz, which was a giant water body that formed at the end of the last ice age as the huge Laurentide ice sheet melted, led to an estimated 100,000 cubic kilometres of fresh water rushing into the North Atlantic.