Paleohydraulics of the last outburst flood from glacial Lake Agassiz and the 8200BP cold event

2004 ◽  
Vol 23 (3-4) ◽  
pp. 389-407 ◽  
Author(s):  
Garry K.C. Clarke ◽  
David W. Leverington ◽  
James T. Teller ◽  
Arthur S. Dyke
Keyword(s):  
Glacial Lake ◽  
Outburst Flood ◽  
Lake Agassiz ◽  
Cold Event ◽  
Glacial Lake Agassiz

scholarly journals Freshwater Discharge, Sediment Transport, and Modeled Climate Impacts of the Final Drainage of Glacial Lake Agassiz

2009 ◽  
Vol 22 (8) ◽  
pp. 2161-2180 ◽  
Author(s):  
Garry K. C. Clarke ◽  
Andrew B. G. Bush ◽  
John W. M. Bush
Keyword(s):  
North Atlantic ◽  
Climate Impacts ◽  
Meridional Overturning Circulation ◽  
Glacial Lake ◽  
Lake Agassiz ◽  
Cold Event ◽  
The North ◽  
Glacial Lake Agassiz ◽  
The North Atlantic ◽  
Ice Production

Abstract A cold event at around 8200 calendar years BP and the release, at around that time, of a huge freshwater outburst from ice-dammed glacial Lake Agassiz have lent support to the idea that the flood triggered the cold event. Some suggest that the freshwater addition caused a weakening of the North Atlantic meridional overturning circulation (MOC) thereby reducing the ocean transport of heat to high northern latitudes. Although several modeling efforts lend strength to this claim, the paleoceanographic record is equivocal. The authors’ aim is to use a coupled ocean–atmosphere model to examine the possibility that the two events are causally linked but that MOC reduction was not the main agent of change. It is found that the outburst flood and associated redirection of postflood meltwater drainage to the Labrador Sea, via Hudson Strait, can freshen the North Atlantic, leading to reduced salinity and sea surface temperature, and thus to increased sea ice production at high latitudes. The results point to the possibility that the preflood outflow to the St. Lawrence was extremely turbid and sufficiently dense to become hyperpycnal, whereas the postflood outflow through Hudson Strait had a lower load of suspended sediment and was buoyant.

Postglacial Diatom Stratigraphy in Relation to the Recession of Glacial Lake Agassiz

1975 ◽  
Vol 5 (4) ◽  
pp. 529-540 ◽  
Author(s):  
J.C. Ritchie ◽  
L.K. Koivo
Keyword(s):  
Sandy Beach ◽  
Sedimentary Environment ◽  
Glacial Lake ◽  
Lake Agassiz ◽  
Organic Detritus ◽  
Sedimentary Environments ◽  
Grand Rapids ◽  
Glacial Lake Agassiz ◽  
Diatom Stratigraphy ◽  
Beach Sands

The sediment and diatom stratigraphy of a small pond on The Pas moraine, near Grand Rapids, Manitoba, reveals a change in sedimentary environment related directly to the last stages of Glacial Lake Agassiz. Beach sands were replaced by clay 7300 14C y. a., then by organic silt and, at 4000 14C y. a. by coarse organic detritus; the corresponding diatom assemblages were (I) a predominantly planktonic spectrum in beach sands, (II) a rich assemblage of nonplanktonic forms, and (III) a distinctly nonplanktonic acidophilous spectrum. These results confirm Elson's (1967) reconstruction of the extent and chronology of the final (Pipun) stage of Glacial Lake Agassiz. The sedimentary environments change from a sandy beach of a large lake at 7300 BP to a small, shallow eutrophic pond with clay and silt deposition from 7000 to 4000 BP. From 4000 BP to the present, organic detritus was deposited in a shallow pond that tended toward dystrophy.

Micromorphology of iceberg scour in clays: Glacial Lake Agassiz, Manitoba, Canada

2012 ◽  
Vol 55 ◽  
pp. 125-144 ◽  
Author(s):  
Lorna D. Linch ◽  
Jaap J.M. van der Meer ◽  
John Menzies
Keyword(s):  
Glacial Lake ◽  
Lake Agassiz ◽  
Glacial Lake Agassiz ◽  
Iceberg Scour
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