A team of researchers have found evidence that climate change on a global scale took place about 13,000 years ago, caused by a flood of biblical proportions.
Previous research had suggested that a massive outpouring of water from glacial Lake Agassiz in Canada may have travelled down the St. Lawrence eastward and out into the Atlantic Ocean, causing significant global climate change. But, writing in the journal Nature this week, geologists from England and Canada have discovered that the outflow likely went north into the Arctic Ocean instead.
Lake Agassiz was a large body of water that covered much of what is now the Canadian prairies, created by the damming of northward drainage by the huge ice sheet that covered much of Canada at this time.
The team of geologists examined boulder gravel in the Athabasca River Valley just north of Fort McMurray, Alberta. This material was deposited when thousands of cubic kilometres of water from glacial Lake Agassiz rushed through the area many millennia ago.
Most importantly, the dating of deposits related to this flood far downstream, near the mouth of the Mackenzie River, has established that this catastrophic flood occurred 13,000 years ago. This coincides with the start of a well-documented cooling period around the globe known as the Younger Dryas, which began a thousand-year-long cold spell.
The researchers note that this new evidence means the outflow from Lake Agassiz was not solely eastward along the St. Lawrence River into the Atlantic Ocean, as had been previously thought.
“This new evidence adds to our view that the outburst flood from Lake Agassiz did lead to a change in ocean circulation and climate cooling,” explains research team member James Teller, geological sciences, University of Manitoba. “This may mean that the ice in the Arctic Ocean was forced out into the North Atlantic and helped change ocean circulation.”
For more information, contact Dr. James Teller, geological sciences, University of Manitoba, at: 204-474-9270.