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| Titel |
Ice stream or not? Radio-echo sounding of Carlson Inlet, West Antarctica |
| VerfasserIn |
E. C. King |
| 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 ; 5, no. 4 ; Nr. 5, no. 4 (2011-10-21), S.907-916 |
| Datensatznummer |
250002749
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| Publikation (Nr.) |
 copernicus.org/tc-5-907-2011.pdf |
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| Zusammenfassung |
| The Antarctic Ice Sheet loses mass to the surrounding ocean mainly by
drainage through a network of ice streams: fast-flowing glaciers bounded on
either side by ice flowing one or two orders of magnitude more slowly. Ice
streams flow despite low driving stress because of low basal resistance but
are known to cease flowing if the basal conditions change, which can take
place when subglacial sediment becomes dewatered by freezing or by a change
in hydraulic pathways. Carlson Inlet, Antarctica has been interpreted as a
stagnated ice stream, based on surface and basal morphology and shallow
radar reflection profiling. To resolve the question of whether the flow
history of Carlson Inlet has changed in the past, I conducted a ground-based
radar survey of Carlson Inlet, the adjacent part of Rutford Ice Stream, and
Talutis Inlet, West Antarctica. This survey provides details of the internal
ice stratigraphy and allows the flow history to be interpreted. Tight
folding of isochrones in Rutford Ice Stream and Talutis Inlet is interpreted
to be the result of lateral compression during convergent flow from a wide
catchment into a narrow, fast-flowing trunk. In contrast, the central part
of Carlson Inlet has gently-folded isochrones that drape over the bed
topography, suggestive of local accumulation and slow flow. A 1-D
thermo-mechanical model was used to estimate the age of the ice. I conclude
that the ice in the centre of Carlson Inlet has been near-stagnant for
between 3500 and 6800 yr and that fast flow has not occurred there during
that time period. |
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