Johnson, J.S. and Pollard, D. and Whitehouse, P.L. and Roberts, S.J. and Rood, D.H. and Schaefer, J.M. (2021) 'Comparing Glacial-Geological Evidence and Model Simulations 1 of Ice Sheet Change since the Last Glacial Period in the Amundsen Sea Sector of Antarctica.', Journal of Geophysical Research - Earth Surface, 126 (6). e2020JF005827.
Since the Last Glacial Maximum ∼20,000 years ago, the Antarctic Ice Sheet has undergone extensive changes, resulting in a much smaller present-day configuration. Improving our understanding of basic physical processes that played important roles during that retreat is critical to providing more robust model projections of future retreat and sea-level rise. Here, a limited-area nested ice sheet model was applied to the last deglacial retreat of the West Antarctic Ice Sheet in the Amundsen Sea Embayment (ASE), at 5 km resolution. The ice sheet response to climate and sea-level forcing was examined at two sites along the flowlines of Pine Island Glacier and Pope Glacier, close to the Hudson Mountains and Mount Murphy respectively, and the simulated responses compared with ice sheet thinning histories derived from glacial-geological data. The sensitivity of results to selected model parameters was also assessed. The model simulations predict a broadly similar response to ocean forcing in both the central and eastern ASE, with an initial rapid phase of thinning followed by a slower phase to the modern configuration. Although there is a mismatch of up to 5,000 years between the timing of simulated and observed thinning, the modeling suggests that the upstream geological records of ice surface elevation change reflect a response to retreat near the grounding line. The model-data mismatch could potentially be improved by accounting for regional variations in mantle viscosity, sea-surface heights and basal sliding properties across the continental shelf.
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|Publisher Web site:||https://doi.org/10.1029/2020JF005827|
|Publisher statement:||© 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.|
|Date accepted:||10 May 2021|
|Date deposited:||17 June 2021|
|Date of first online publication:||12 May 2021|
|Date first made open access:||17 June 2021|
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