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Reconstruction of ice-sheet changes in the Antarctic Peninsula since the Last Glacial Maximum

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posted on 12.06.2015, 13:51 authored by Colm O Cofaigh, Bethan J. Davies, Stephen J. Livingstone, James A. Smith, Joanne S. Johnson, Emma P. Hocking, Dominic A. Hodgson, John B. Anderson, Michael J. Bentley, Miquel Canals, Eugene Domack, Julian A. Dowdeswell, Jeffrey EvansJeffrey Evans, Neil F. Glasser, Claus-Dieter Hillenbrand, Robert D. Larter, Stephen J. Roberts, Alexander R. Simms
This paper compiles and reviews marine and terrestrial data constraining the dimensions and configuration of the Antarctic Peninsula Ice Sheet (APIS) from the Last Glacial Maximum (LGM) through deglaciation to the present day. These data are used to reconstruct grounding-line retreat in 5ka time-steps from 25kaBP to present. Glacial landforms and subglacial tills on the eastern and western Antarctic Peninsula (AP) shelf indicate that the APIS was grounded to the outer shelf/shelf edge at the LGM and contained a series of fast-flowing ice streams that drained along cross-shelf bathymetric troughs. The ice sheet was grounded at the shelf edge until ~20calkaBP. Chronological control on retreat is provided by radiocarbon dates on glacimarine sediments from the shelf troughs and on lacustrine and terrestrial organic remains, as well as cosmogenic nuclide dates on erratics and ice moulded bedrock. Retreat in the east was underway by about 18calkaBP. The earliest dates on recession in the west are from Bransfield Basin where recession was underway by 17.5calkaBP. Ice streams were active during deglaciation at least until the ice sheet had pulled back to the mid-shelf. The timing of initial retreat decreased progressively southwards along the western AP shelf; the large ice stream in Marguerite Trough may have remained grounded at the shelf edge until about 14calkaBP, although terrestrial cosmogenic nuclide ages indicate that thinning had commenced by 18kaBP. Between 15 and 10calkaBP the APIS underwent significant recession along the western AP margin, although retreat between individual troughs was asynchronous. Ice in Marguerite Trough may have still been grounded on the mid-shelf at 10calkaBP. In the Larsen-A region the transition from grounded to floating ice was established by 10.7-10.6calkaBP. The APIS had retreated towards its present configuration in the western AP by the mid-Holocene but on the eastern peninsula may have approached its present configuration several thousand years earlier, by the start of the Holocene. Mid to late-Holocene retreat was diachronous with stillstands, re-advances and changes in ice-shelf configuration being recorded in most places. Subglacial topography exerted a major control on grounding-line retreat with grounding-zone wedges, and thus by inference slow-downs or stillstands in the retreat of the grounding line, occurring in some cases on reverse bed slopes.

Funding

This review is a contribution to the ‘Reconstruction of Antarctic Ice Sheet Deglaciation’ project which is supported by the Scientific Committee for Antarctic Research Antarctic Climate Evolution Programme (SCAR-ACE). The research that underpins this review was supported in numerous grants over many years awarded through various funding agencies but notably the UK Natural Environment Research Council (NERC), the USA National Science Foundation (Office of Polar Programs), the Spanish National Antarctic Program and MINECO Polar Research Area, and the Catalonian government.

History

Department

  • Geography and Environment

Published in

Quaternary Science Reviews

Volume

100

Pages

87 - 110

Citation

O COFAIGH, C. ... et al, 2014. Reconstruction of ice-sheet changes in the Antarctic Peninsula since the Last Glacial Maximum. Quaternary Science Reviews, 100, pp. 87 - 110.

Publisher

Elsevier Ltd / © Durham University

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/

Acceptance date

18/06/2014

Publication date

2014-08-07

Copyright date

2014

Notes

This is an Open Access article published by Elsevier and distributed under a Creative Commons Attribution Licence CC-BY 3.0 http://creativecommons.org/licenses/by/3.0/ which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

ISSN

0277-3791

Language

en