Age determination for sediment cores from the Amundsen Sea Embayment ...
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 fr...
Main Authors: | , , , , , , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
PANGAEA
2014
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Subjects: | |
Online Access: | https://dx.doi.org/10.1594/pangaea.835462 https://doi.pangaea.de/10.1594/PANGAEA.835462 |
Summary: | 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 ... : Supplement to: 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 (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 ... |
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