Glacial retreat in the Amundsen Sea sector, West Antarctica – first cosmogenic evidence from central Pine Island Bay and the Kohler Range

Lindow, Julia; Castex, Marion; Wittmann, Hella; Johnson, Joanne S. ORCID: https://orcid.org/0000-0003-4537-4447; Lisker, Frank; Gohl, Karsten; Spiegel, Cornelia. 2014 Glacial retreat in the Amundsen Sea sector, West Antarctica – first cosmogenic evidence from central Pine Island Bay and the Kohler Range. Quaternary Science Reviews, 98. 166-173. https://doi.org/10.1016/j.quascirev.2014.05.010

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Text This article has been accepted for publication and will appear in a revised form in Quaternary Science Reviews, published by Elsevier. Copyright Elsevier. JLindow_submitted_revised_Manuscript_120514.docx - Accepted Version Download (3MB)

Abstract/Summary

The Amundsen Sea Embayment of West Antarctica hosts one of the most rapidly changing sectors of the West Antarctic Ice Sheet. With the fastest-flowing ice streams in Antarctica, the region around Pine Island Bay is characterized by rapid ice-sheet thinning and grounding-line retreat. Published surface-exposure data are limited to a few isolated nunataks making it difficult to assess the long-term deglacial history of the area. To address this, we correlate existing records of lateral ice-stream retreat from marine sediment cores with onshore glacial thinning in two key areas of eastern Marie Byrd Land: the Kohler Range and Pine Island Bay. Our 10Be surface-exposure ages are the first from the isolated Kohler Range and show that the nunataks there became ice-free between 8.6 and 12.6 ka. This implies a minimum long-term average thinning rate of 3.3 ± 0.3 cm/yr, which is one order of magnitude lower than recent rates based on satellite data. We also present pre- to early Holocene 10Be surface-exposure ages from two islands located approximately 80 km downstream of the Pine Island Glacier ice-shelf front to constrain the lateral deglacial history in the Pine Island Bay area. This study provides insight into the significance of local ice sheet variations and suggests that the post-LGM history in the Amundsen Sea sector was characterized by glacial thinning as well as lateral retreat in pre- to early Holocene times.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.quascirev.2014.05.010
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ice Sheets
ISSN:	02773791
Additional Keywords:	surface exposure dating, Amundsen Sea Embayment, West Antarctic Ice Sheet, deglaciation history, Holocene, Pine Island Bay, Kohler Range, cosmogenic isotopes, glacial retreat
Date made live:	15 Jul 2014 08:36 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/507825

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