Freshwater Outburst from Lake Superior as a Trigger for the Cold Event 9300 Years Ago

Down the Drain A pervasive cooling event affected much of the Northern Hemisphere approximately 9300 years ago. This event was accompanied by changes in ocean circulation in the North Atlantic, forced presumably by a large injection of fresh water produced by melting of the Laurentide Ice Sheet, but...

Full description

Bibliographic Details
Published in:Science
Main Authors: Yu, Shi-Yong, Colman, Steven M., Lowell, Thomas V., Milne, Glenn A., Fisher, Timothy G., Breckenridge, Andy, Boyd, Matthew, Teller, James T.
Format: Article in Journal/Newspaper
Language:English
Published: American Association for the Advancement of Science (AAAS) 2010
Subjects:
Lawrence River
North Bay
Ice Sheet
North Atlantic
Online Access:https://doi.org/10.1126/science.1187860
https://www.science.org/doi/pdf/10.1126/science.1187860
Description
Summary:Down the Drain A pervasive cooling event affected much of the Northern Hemisphere approximately 9300 years ago. This event was accompanied by changes in ocean circulation in the North Atlantic, forced presumably by a large injection of fresh water produced by melting of the Laurentide Ice Sheet, but the source, magnitude, and routing of the meltwater remain unknown. Yu et al. (p. 1262 , published online 29 April) present evidence that the trigger for this cooling episode was an outburst flood from Lake Superior. Reconstructing lake-level changes in the Superior basin suggests that a rapid fall of lake level of about 45 meters occurred 9300 years ago, possibly due to the sudden failure of a drift dam. Rapid drainage through the North Bay–Ottawa River–St. Lawrence River valleys into the North Atlantic should have been sufficient to disturb ocean circulation in line with the geologic record.

Similar Items