Submarine glacial landforms and rates of ice-stream collapse

The rate of deglacial ice-sheet retreat across polar continental shelves, and possible ice-stream collapse and sea-level rise, has been much debated. High-resolution imagery of seafloor morphology is available for many polar shelves and fjords. The rapidity of ice retreat is inferred from diagnostic...

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Bibliographic Details
Published in:Geology (Boulder) 2008-10, Vol.36 (10), p.819-822
Main Authors: Dowdeswell, J. A, Ottesen, D, Evans, J, Ó Cofaigh, C, Anderson, J. B
Format: Article
Language:English
Subjects:
Antarctic Peninsula
Antarctica
Arctic Ocean
Arctic region
bottom features
continental shelf
deglaciation
Europe
Geology
glacial features
glacial geology
Glaciers
grounded ice
ice movement
ice sheets
ice streams
Icebergs
Marine
marine environment
moraines
Northern Norway
Norway
Oceanography
periodicity
rates
Ross Sea
Scandinavia
Sea level
Southern Ocean
submarine environment
Svalbard
Western Europe
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Summary:The rate of deglacial ice-sheet retreat across polar continental shelves, and possible ice-stream collapse and sea-level rise, has been much debated. High-resolution imagery of seafloor morphology is available for many polar shelves and fjords. The rapidity of ice retreat is inferred from diagnostic assemblages of submarine landforms, produced at ice-stream sedimentary beds. These landforms, exposed by ice retreat across high-latitude shelves, demonstrate that deglaciation occurs in three main ways: rapidly, by flotation and breakup; episodically, by still-stands and/or grounding events punctuating rapid retreat; or by slower retreat of grounded ice. Submarine landform assemblages imply, through the presence of grounding-zone wedges overprinting mega-scale glacial lineations on many polar shelves, that ice-stream retreat is more often episodic than catastrophic. These observations provide a robust test of the ability of numerical models to predict the varied response of ice-sheet basins to environmental changes.
ISSN:0091-7613
1943-2682
DOI:10.1130/G24808A.1