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

TitleFreshwater Outburst from Lake Superior as a Trigger for the Cold Event 9300 Years Ago
Publication TypeJournal Article
Year of Publication2010
AuthorsYu, S-Y, Colman, SM, Lowell, TV, Milne, GA, Fisher, TG, Breckenridge, A, Boyd, M, Teller, JT
JournalScience
Volume328
Issue5983
Pagination1262-1266
ISSN0036-8075
Abstract

Paleoclimate proxy records reveal a pervasive cooling event with a Northern Hemispheric extent similar to 9300 years ago. Coeval changes in the oceanic circulation of the North Atlantic imply freshwater forcing. However, the source, magnitude, and routing of meltwater have remained unknown. Located in central North America, Lake Superior is a key site for regulating the outflow of glacial meltwater to the oceans. Here, we show evidence for an similar to 45-meter rapid lake-level fall in this basin, centered on 9300 calibrated years before the present, due to the failure of a glacial drift dam on the southeast corner of the lake. We ascribe the widespread climate anomaly similar to 9300 years ago to this freshwater outburst delivered to the North Atlantic Ocean through the Lake Huron-North Bay-Ottawa River-St. Lawrence River valleys.

DOI10.1126/science.1187860