Subglacial bedforms reveal complex basal regime in a zone of paleo-ice stream convergence, Amundsen Sea embayment, West Antarctica

Larter, R.D. ORCID: https://orcid.org/0000-0002-8414-7389; Graham, A.G.C.; Gohl, K.; Kuhn, G.; Hillenbrand, C.-D. ORCID: https://orcid.org/0000-0003-0240-7317; Smith, J.A. ORCID: https://orcid.org/0000-0002-1333-2544; Deen, T.J.; Livermore, R.A.; Schenke, H.-W.. 2009 Subglacial bedforms reveal complex basal regime in a zone of paleo-ice stream convergence, Amundsen Sea embayment, West Antarctica. Geology, 37 (5). 411-414. 10.1130/G25505A.1

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Official URL: http://dx.doi.org/10.1130/G25505A.1

Abstract/Summary

The flow of ice streams, which account for most discharge from large ice sheets, is controlled by processes operating at the ice stream bed. Data from modern ice stream beds are difficult to obtain, but where ice advanced onto continental shelves during glacial periods, extensive areas of the former bed can be imaged using modern swath sonar tools. We present new multibeam swath bathymetry data analyzed alongside sparse preexisting data from the Amundsen Sea embayment. The compilation is the most extensive, continuous area of multi-beam data coverage yet obtained on the inner continental shelf of Antarctica. The data reveal streamlined subglacial bedforms that define a zone of paleo–ice stream convergence, but, in contrast to previous models, do not show a simple downflow progression of bedform types along paleo–ice stream troughs. We interpret high spatial variability of bedforms as indicating a complex mechanical and hydrodynamic regime at the former ice stream beds, consistent with observations from some modern ice streams. We conclude that care must be taken when using bedforms to infer paleo–ice stream velocities.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1130/G25505A.1
Programmes:	BAS Programmes > Global Science in the Antarctic Context (2005-2009) > Glacial Retreat in Antarctica and Deglaciation of the Earth System
ISSN:	0091-7613
NORA Subject Terms:	Glaciology Earth Sciences
Date made live:	10 Feb 2010 15:31 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/8456

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1130/G25505A.1

Programmes:

BAS Programmes > Global Science in the Antarctic Context (2005-2009) > Glacial Retreat in Antarctica and Deglaciation of the Earth System

ISSN:

0091-7613

NORA Subject Terms:

Glaciology
Earth Sciences

Date made live:

10 Feb 2010 15:31 +0 (UTC)