Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics
The Antarctic bedrock is evolving as the solid Earth responds to the past and ongoing evolution of the ice sheet. A recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) has generally been losing its mass since the Last Glacial Maximum. In a sustained warming climate, the...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20140017427 2023-05-15T13:22:10+02:00 Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics Nowicki, S. Morlighem, Mathieu Ivins, Erik R. Seroussi, Helene L. Larour, Eric Y. Adhikari, Surendra Unclassified, Unlimited, Publicly available June 30, 2014 application/pdf http://hdl.handle.net/2060/20140017427 unknown Document ID: 20140017427 http://hdl.handle.net/2060/20140017427 Copyright, Distribution as joint owner in the copyright CASI Geophysics GSFC-E-DAA-TN16447 Solid Earth: Open Access; 5; 1; 569-584 2014 ftnasantrs 2019-07-21T00:21:04Z The Antarctic bedrock is evolving as the solid Earth responds to the past and ongoing evolution of the ice sheet. A recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) has generally been losing its mass since the Last Glacial Maximum. In a sustained warming climate, the AIS is predicted to retreat at a greater pace, primarily via melting beneath the ice shelves.We employ the glacial isostatic adjustment (GIA) capability of the Ice Sheet System Model (ISSM) to combine these past and future ice loadings and provide the new solid Earth computations for the AIS.We find that past loading is relatively less important than future loading for the evolution of the future bed topography. Our computations predict that the West Antarctic Ice Sheet (WAIS) may uplift by a few meters and a few tens of meters at years AD 2100 and 2500, respectively, and that the East Antarctic Ice Sheet is likely to remain unchanged or subside minimally except around the Amery Ice Shelf. The Amundsen Sea Sector in particular is predicted to rise at the greatest rate; one hundred years of ice evolution in this region, for example, predicts that the coastline of Pine Island Bay will approach roughly 45mmyr1 in viscoelastic vertical motion. Of particular importance, we systematically demonstrate that the effect of a pervasive and large GIA uplift in the WAIS is generally associated with the flattening of reverse bed slope, reduction of local sea depth, and thus the extension of grounding line (GL) towards the continental shelf. Using the 3-D higher-order ice flow capability of ISSM, such a migration of GL is shown to inhibit the ice flow. This negative feedback between the ice sheet and the solid Earth may promote stability in marine portions of the ice sheet in the future. Other/Unknown Material Amery Ice Shelf Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Bay NASA Technical Reports Server (NTRS) Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Amery Ice Shelf ENVELOPE(71.000,71.000,-69.750,-69.750) Amundsen Sea Antarctic East Antarctic Ice Sheet Island Bay ENVELOPE(-109.085,-109.085,59.534,59.534) Pine Island Bay ENVELOPE(-102.000,-102.000,-74.750,-74.750) The Antarctic West Antarctic Ice Sheet |
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Open Polar |
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NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Geophysics |
spellingShingle |
Geophysics Nowicki, S. Morlighem, Mathieu Ivins, Erik R. Seroussi, Helene L. Larour, Eric Y. Adhikari, Surendra Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics |
topic_facet |
Geophysics |
description |
The Antarctic bedrock is evolving as the solid Earth responds to the past and ongoing evolution of the ice sheet. A recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) has generally been losing its mass since the Last Glacial Maximum. In a sustained warming climate, the AIS is predicted to retreat at a greater pace, primarily via melting beneath the ice shelves.We employ the glacial isostatic adjustment (GIA) capability of the Ice Sheet System Model (ISSM) to combine these past and future ice loadings and provide the new solid Earth computations for the AIS.We find that past loading is relatively less important than future loading for the evolution of the future bed topography. Our computations predict that the West Antarctic Ice Sheet (WAIS) may uplift by a few meters and a few tens of meters at years AD 2100 and 2500, respectively, and that the East Antarctic Ice Sheet is likely to remain unchanged or subside minimally except around the Amery Ice Shelf. The Amundsen Sea Sector in particular is predicted to rise at the greatest rate; one hundred years of ice evolution in this region, for example, predicts that the coastline of Pine Island Bay will approach roughly 45mmyr1 in viscoelastic vertical motion. Of particular importance, we systematically demonstrate that the effect of a pervasive and large GIA uplift in the WAIS is generally associated with the flattening of reverse bed slope, reduction of local sea depth, and thus the extension of grounding line (GL) towards the continental shelf. Using the 3-D higher-order ice flow capability of ISSM, such a migration of GL is shown to inhibit the ice flow. This negative feedback between the ice sheet and the solid Earth may promote stability in marine portions of the ice sheet in the future. |
format |
Other/Unknown Material |
author |
Nowicki, S. Morlighem, Mathieu Ivins, Erik R. Seroussi, Helene L. Larour, Eric Y. Adhikari, Surendra |
author_facet |
Nowicki, S. Morlighem, Mathieu Ivins, Erik R. Seroussi, Helene L. Larour, Eric Y. Adhikari, Surendra |
author_sort |
Nowicki, S. |
title |
Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics |
title_short |
Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics |
title_full |
Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics |
title_fullStr |
Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics |
title_full_unstemmed |
Future Antarctic Bed Topography and Its Implications for Ice Sheet Dynamics |
title_sort |
future antarctic bed topography and its implications for ice sheet dynamics |
publishDate |
2014 |
url |
http://hdl.handle.net/2060/20140017427 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(71.000,71.000,-69.750,-69.750) ENVELOPE(-109.085,-109.085,59.534,59.534) ENVELOPE(-102.000,-102.000,-74.750,-74.750) |
geographic |
Amery Amery Ice Shelf Amundsen Sea Antarctic East Antarctic Ice Sheet Island Bay Pine Island Bay The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Amery Amery Ice Shelf Amundsen Sea Antarctic East Antarctic Ice Sheet Island Bay Pine Island Bay The Antarctic West Antarctic Ice Sheet |
genre |
Amery Ice Shelf Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Bay |
genre_facet |
Amery Ice Shelf Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Pine Island Bay |
op_source |
CASI |
op_relation |
Document ID: 20140017427 http://hdl.handle.net/2060/20140017427 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766363619146072064 |