Glacial Lake Ojibway

Glacial Lake Ojibway was a prehistoric lake in what is now Northern Ontario. Ojibway was the last of the great proglacial lakes of the last ice age. Comparable in size to Lake Agassiz (to which it was probably linked), and north of the Great Lakes, it was at its greatest extent c. 8,500 years BP.

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 above sea level. (A comparable mechanism produced the Missoula floods that created the Channeled scablands of the Columbia River basin.)

A more recent analysis states "unequivocal evidence is still lacking in order to define the way the lake drained (i.e., either by a breach through the ice-dam, a supraglacial spillover or a subglacial flood), whether it drained by one or more pulses and the location of the northward flood routes toward Hudson Bay" and proposes that new evidence indicates that the process was in fact subglacial flooding. [Lajeunesse, P.; St-Onge, G. Reconstruction of the Last Outburst Flood of Glacial Lake Agassiz-Ojibway in Hudson Bay and Hudson Strait. American Geophysical Union, Fall Meeting 2007, abstract #C51A-0075 12/2007 Abstract retrieved February 24, 2008 from http://adsabs.harvard.edu/abs/2007AGUFM.C51A0075L See also AFP Sun Feb 24, 3:42 PM , “How it happened: The catastrophic flood that cooled the Earth” retrieved Feb 25, 2008 from http://ca.news.yahoo.com/s/afp/080224/canada/science_climate_ice_canada_1 ]

The draining of Lake Ojibway was the most likely cause of the 8.2 kiloyear event, which involved widespread climate change.

ee also

* List of prehistoric lakes
* Tyrrell Sea

References

* Pielou, E.C. "After the Ice Age". Chicago: University of Chicago Press, 1991.

* Lajeunesse, P.; St-Onge, G. "Reconstruction of the Last Outburst Flood of Glacial Lake Agassiz-Ojibway in Hudson Bay and Hudson Strait," American Geophysical Union, Fall Meeting 2007, abstract #C51A-0075 12/2007 Abstract retrieved February 24, 2008 from http://adsabs.harvard.edu/abs/2007AGUFM.C51A0075L

External links

* AFP Sun Feb 24, 3:42 PM , “How it happened: The catastrophic flood that cooled the Earth” retrieved Feb 25, 2008 from http://ca.news.yahoo.com/s/afp/080224/canada/science_climate_ice_canada_1