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| Titel |
Bathymetric and oceanic controls on Abbot Ice Shelf thickness and stability |
| VerfasserIn |
J. R. Cochran, S. S. Jacobs, K. J. Tinto, R. E. Bell |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 8, no. 3 ; Nr. 8, no. 3 (2014-05-15), S.877-889 |
| Datensatznummer |
250116153
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| Publikation (Nr.) |
 copernicus.org/tc-8-877-2014.pdf |
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| Zusammenfassung |
| Ice shelves play key roles in stabilizing Antarctica's ice sheets,
maintaining its high albedo and returning freshwater to the Southern Ocean.
Improved data sets of ice shelf draft and underlying bathymetry are important
for assessing ocean–ice interactions and modeling ice response to climate
change. The long, narrow Abbot Ice Shelf south of Thurston Island produces a
large volume of meltwater, but is close to being in overall mass balance.
Here we invert NASA Operation IceBridge (OIB) airborne gravity data over the
Abbot region to obtain sub-ice bathymetry, and combine OIB elevation and ice
thickness measurements to estimate ice draft. A series of asymmetric
fault-bounded basins formed during rifting of Zealandia from Antarctica
underlie the Abbot Ice Shelf west of 94° W and the Cosgrove Ice
Shelf to the south. Sub-ice water column depths along OIB flight lines are
sufficiently deep to allow warm deep and thermocline waters observed near
the western Abbot ice front to circulate through much of the ice shelf
cavity. An average ice shelf draft of ~200 m, 15% less
than the Bedmap2 compilation, coincides with the summer transition between
the ocean surface mixed layer and upper thermocline. Thick ice streams
feeding the Abbot cross relatively stable grounding lines and are rapidly
thinned by the warmest inflow. While the ice shelf is presently in
equilibrium, the overall correspondence between draft distribution and
thermocline depth indicates sensitivity to changes in characteristics of the
ocean surface and deep waters. |
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