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| Titel |
Sensitivity of last deglacial and modern Antarctic Ice Sheet to the distribution of basal roughness |
| VerfasserIn |
D. Pollard, R. M. DeConto |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250064105
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| Zusammenfassung |
| The distributions of basal roughness and deformable sediment versus hard
bedrock underneath Antarctica are poorly known, yet have a large influence
on the geometry of the Antarctic Ice Sheet. Most paleoclimatic
continental-scale ice-sheet simulations to date have assumed very
simple distributions, which probably contribute to the large errors found
in modern surface ice elevations. Here a crude inverse method is used to
deduce the distribution of basal sliding coefficients, by fitting to modern
observed surface elevations in a 3-D hybrid ice sheet-shelf model.
Modern errors in ice elevation are considerably reduced, from several
hundred meters to a few tens of meters in most areas. However, it is found
that the simulated total ice volume at Last Glacial Maximum ~15 ka,
deglacial retreat history, and contribution to eustatic sea-level rise
are quite sensitive to the new sliding-coefficient distribution, and also
to the value assumed on continental shelves. Last deglacial results are
presented, and model-data comparisons that could reduce the model
uncertainty are discussed. |
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