In:
Science Advances, American Association for the Advancement of Science (AAAS), Vol. 5, No. 4 ( 2019-04-05)
Kurzfassung:
Ice sheet mass loss is currently dominated by fast-flowing glaciers (ice streams) terminating in the ocean as ice shelves and resting on beds below sea level. The factors controlling ice-stream flow and retreat over longer time scales ( 〉 100 years), especially the role of three-dimensional bed shape and bed strength, remain major uncertainties. We focus on a former ice stream where trough shape and bed substrate are known, or can be defined, to reconstruct ice-stream retreat history and grounding-line movements over 15 millennia since the Last Glacial Maximum. We identify a major behavioral step change around 18,500 to 16,000 years ago—out of tune with external forcing factors—associated with the collapse of floating ice sectors and rapid ice-front retreat. We attribute this step change to a marked geological transition from a soft/weak bed to a hard/strong bed coincident with a change in trough geometry. Both these factors conditioned and ultimately hastened ice-stream demise.
Materialart:
Online-Ressource
ISSN:
2375-2548
DOI:
10.1126/sciadv.aau1380
Sprache:
Englisch
Verlag:
American Association for the Advancement of Science (AAAS)
Publikationsdatum:
2019
ZDB Id:
2810933-8
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