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Late Quaternary grounded ice extent in the Filchner Trough, Weddell Sea, Antarctica: new marine geophysical evidence

Larter, Robert D.; Graham, Alastair G.C.; Hillenbrand, Claus-Dieter; Smith, James A.; Gales, Jennifer A.. 2012 Late Quaternary grounded ice extent in the Filchner Trough, Weddell Sea, Antarctica: new marine geophysical evidence. Quaternary Science Reviews, 53. 111-122. 10.1016/j.quascirev.2012.08.006

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Abstract/Summary

The Last Glacial Maximum (LGM; ca 23–19 ka BP) extent of grounded ice in the Filchner Trough, a major cross shelf trough extending seaward from the Filchner Ice Shelf in the southern Weddell Sea, has been much debated. Here we present data from the first extensive multibeam swath bathymetry and sub-bottom acoustic profiling surveys in the Filchner Trough that include several parallel survey lines with overlapping swaths. We interpret these new data, combined with published observations and radiocarbon dates from sediment cores, as indicating that the grounding line in the Filchner Trough during the LGM advanced beyond the middle shelf, probably to within 40 km of the shelf break, and possibly reached the shelf break. Three different hypotheses are discussed that could reconcile this interpretation with interpretations, based on ice coring and surface exposure age data, that LGM ice surface elevations in areas draining into the Filchner and Ronne ice shelves were no more than a few hundred metres higher than today: (1) ice plain conditions extended along most of the Filchner Trough; (2) the ice shelf advanced and thickened so that it “touched down” on the continental shelf for a short period; (3) LGM ice drainage pathways in the interior of the Weddell Sea embayment were different from those observed today.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1016/j.quascirev.2012.08.006
Programmes: BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ice Sheets
ISSN: 0277-3791
Additional Keywords: Antarctic; Ice sheet; Last Glacial Maximum; Bathymetry; Acoustic profile; Geomorphology; Bedform; Lineation; Furrow; Grounding zone wedge
Date made live: 04 May 2012 07:52
URI: http://nora.nerc.ac.uk/id/eprint/17873

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