Lake Ojibway

Glacial Lake Agassiz and Lake Ojibway (7,900 YBP)

Lake Ojibway was a prehistoric lake in what is now northern Ontario and Quebec in Canada. Ojibway was the last of the great proglacial lakes of the last ice age.^[1] Comparable in size to Lake Agassiz (to which it is likely to be linked), and north of the Great Lakes, it was at its greatest extent c. 8,500 years BP. The former lakebed forms the modern Clay Belt, an area of fertile land.^[2]

Lake Ojibway was relatively short-lived. The lake drained in what must have been a catastrophic and dramatic manner around 8,200 years BP. One hypothesis is that a weakening ice dam separating it from Hudson Bay broke, as the lake was roughly 250 m (820 ft) above sea level. A comparable mechanism produced the Missoula floods that created the channeled scablands of the Columbia River basin.^[2]

A recent analysis states it has not been conclusively determined whether the lake drained by a breach of the ice dam, by water spilling over the glacier, or by a flood under the glacier. It is also not conclusively known whether there were one or more pulses, and the route the water took to reach Hudson's Bay has not been determined.^[2][3]

The draining of Lake Ojibway is a possible cause of the 8.2 kiloyear event, a major global cooling that occurred 8,200 years BP.

See also

• Tyrrell Sea
• Glacial lake outburst flood
• Lake Agassiz
• Glacial Lake Missoula
• List of prehistoric lakes
• Deluge (prehistoric)

References

1. Coleman, Arthur Philemon (1909). "Lake Ojibway; Last of the Great Glacial Lakes" (PDF). Ontario Bureau of Mines. Report 18 (4): 284–293. Retrieved 30 October 2015.
2. Lajeunesse, P.; St-Onge, G. (2007). "Reconstruction of the Last Outburst Flood of Glacial Lake Agassiz-Ojibway in Hudson Bay and Hudson Strait". American Geophysical Union, Fall Meeting 2007. Retrieved 2012-09-24.
3. Pielou, E.C. (1991). After the Ice Age. Chicago: University of Chicago Press. ISBN 9780226668123.

External links

• "How it happened: The catastrophic flood that cooled the Earth". Cosmos Magazine. 2008-02-25. Retrieved 2012-09-27.