Glacial Lake Agassiz




During the deglaciation of the Northern Hemisphere, which started around 20,000 years ago and ended around 8,000 years ago, giant lakes formed at the edges of ice sheets in North America and Eurasia. Some of these lakes were dammed by the disappearing ice sheets and on some occasions these dams failed, producing gigantic floods. The largest of these lakes was Glacial Lake Agassiz ice dam dammed by the waning Laurentide Ice Sheet. The final drainage of this lake produced a flood that released 150,000 km3 northward to Hudson Bay. Ultimately the freshwater released from the flood was routed to the Atlantic Ocean. The ocean response to this huge influx of freshwater is thought to be the trigger for the cold event that occcurred around 8,200 years ago. However, many questions remain to be answered.



Clarke, G. K. C., D. W. Leverington, J. T. Teller, A. S. Dyke, and S. J. Marshall. 2005. Fresh arguments against the Shaw megaflood hypothesis. Quaternary Science Reviews, 24, 1533-1541.

Clarke, G. K. C., D.W. Leverington, J. T. Teller, and A. S. Dyke. 2004. Paleohydraulics of the last outburst flood from glacial Lake Agassiz and the 8,200 BP cold event. Quaternary Science Reviews, 23, 389-407.

Clarke, G. K. C., D. W. Leverington, J. T. Teller, and A. S. Dyke. 2003. Superlakes, megafloods, and abrupt climate change. Science, 301, 922-923.

Mangerud, J., M. Jakobsson, H. Alexanderson, V. Astakhov, G. K. C. Clarke, M. Henriksen, C. Hjort, G. Krinner, J.-P. Lunkka, P. Möller, A. Murray, O. Nikolskaya, M. Saarnisto, and J. I. Svendsen. 2004. Ice-dammed lakes and rerouting of the drainage of Northern Eurasia during the last glaciation. Quaternary Science Reviews, 23, 13131332.