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Titel |
Future Antarctic bed topography and its implications for ice sheet dynamics |
VerfasserIn |
S. Adhikari, E. R. Ivins, E. Larour, H. Seroussi, M. Morlighem, S. Nowicki |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1869-9510
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Digitales Dokument |
URL |
Erschienen |
In: Solid Earth ; 5, no. 1 ; Nr. 5, no. 1 (2014-06-30), S.569-584 |
Datensatznummer |
250115288
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Publikation (Nr.) |
copernicus.org/se-5-569-2014.pdf |
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Zusammenfassung |
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
45 mm yr−1 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. |
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