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Author Smith, James A ♦ Hillenbrand, Claus-Dieter ♦ Kuhn, Gerhard ♦ Klages, Johann Philipp ♦ Graham, Alastair G C ♦ Larter, Robert D ♦ Ehrmann, Werner ♦ Moreton, Steven Grahame ♦ Wiers, Steffen ♦ Frederichs, Thomas
Source PANGAEA
Content type Text
Publisher PANGAEA
File Format ZIP
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Earth sciences ♦ Geology, hydrology & meteorology
Subject Keyword Land Surface
Abstract Glaciers flowing into the Amundsen Sea Embayment (ASE) account for > 35% of the total discharge of the West Antarctic Ice Sheet (WAIS) and have thinned and retreated dramatically over the past two decades. Here we present detailed marine geological data and an extensive new radiocarbon dataset from the eastern ASE in order to constrain the retreat of the WAIS since the Last Glacial Maximum (LGM) and assess the significance of these recent changes. Our dating approach, relying mainly on the acid insoluble organic (AIO) fraction, utilises multi-proxy analyses of the sediments to characterise their lithofacies and determine the horizon in each core that would yield the most reliable age for deglaciation. In total, we dated 69 samples and show that deglaciation of the outer shelf was underway before 20,600 calibrated years before present (cal. yr BP), reaching the mid-shelf by 13,575 cal. yr BP and the inner shelf to within c.150 km of the present grounding line by 10,615 cal. yr BP. The timing of retreat is broadly consistent with previously published radiocarbon dates on biogenic carbonate from the eastern ASE as well as AIO 14C ages from the western ASE and provides new constraints for ice sheet models. The overall retreat trajectory - slow on the outer shelf, more rapid from the middle to inner shelf - clearly highlights the importance of reverse bedslopes in controlling phases of accelerated groundling line retreat. Despite revealing these broad scale trends, the current dataset does not capture detailed changes in ice flow, such as stillstands during grounding line retreat (i.e., deposition of grounding zone wedges) and possible readvances as depicted in the geomorphological record.
Temporal Coverage 2006-02-08T23:59:00/2010-03-20T08:42:00
Spatial Coverage Latitude: -72.920947;Longitude: -105.387368
Description Note: 30 datasets
Part of series Supplement to: Smith, JA et al. (2014): New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum. Global and Planetary Change, 122, 224-237, https://doi.org/10.1016/j.gloplacha.2014.07.015
Educational Use Research
Learning Resource Type Data Set
Publisher Date 2014-09-02
Rights License https://creativecommons.org/licenses/by/3.0/


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