CGRG Bibliography of Canadian Geomorphology
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Author : Carlson, A.E.; Clark, P.U.; Haley, B.A.; and Klinkhammer, G.P.
Date : 2009.
Title : Routing of western Canadian Plains runoff during the 8.2 ka cold event.
Publication : Geophysical Research Letters
Issue : 36(L14704):
Page(s) : doi:10.1029/2009GL038778.
Abstract
The collapse of the Laurentide Ice Sheet over Hudson Bay ~8.47 ka allowed the rapid drainage of glacial Lake Agassiz into the Labrador Sea, an event identified as causing a reduction in Atlantic meridional overturning circulation (AMOC) and the 8.2 ka cold event. Atmosphere-ocean models simulations based on this forcing, however, fail to reproduce several characteristics of this event, particularly its duration. Here we use planktonic foraminifera U/Ca records to document the routing of western Canadian Plains runoff that accompanied ice-sheet collapse. Geochemical modeling of the ~7 nmol/mol increase in U/Ca at the opening of Hudson Bay indicates an increase in freshwater discharge of 0.13 ± 0.03 Sverdrups (106 m3 s-1) from routing, a sufficient magnitude to cause an AMOC reduction. We suggest that this routing event suppressed AMOC strength for several centuries after the drainage of Lake Agassiz, explaining multi-centennial climate anomalies associated with the 8.2 ka cold event.
Bibliography of Canadian Geomorphology