Acceleration of Jakobshavn Isbrae Triggered by Warm, Subsurface Irminger Waters
Abstract
Observations over the past decade show a rapid acceleration of several outlet glaciers in Greenland and Antarctica. Among the largest changes seen, Jakobshavn Isbrae(JI), an outlet glacier feeding a deep ocean fjord on the west coast of Greenland, recently, and suddenly, switched its behavior from slow thickening prior to 1997 to subsequent rapid thinning and a doubling in glacier velocity. Suggested reasons for the JI speedup range from increased lubrication of the ice-bedrock interface as more meltwater drains to the bed during recently warmer summers, to weakening and breakup of the floating ice tongue. Here, we present evidence that the changes of the JI were in fact triggered by an increase in subsurface ocean temperature, based on hydrographic data showing a sudden jump during 1997 along the entire west coast of Greenland. This arrival of upstream, Irminger Sea warm water, originating near Iceland, was driven by changes in atmospheric circulation in the North Atlantic.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.C41D..01H
- Keywords:
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- 0700 CRYOSPHERE (4540);
- 0728 Ice shelves;
- 4200 OCEANOGRAPHY: GENERAL