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| Titel |
Changes of Wilkins Ice Shelf over the past 15 years and inferences on its stability |
| VerfasserIn |
M. Braun, A. Humbert, A. Moll |
| 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 ; 3, no. 1 ; Nr. 3, no. 1 (2009-03-18), S.41-56 |
| Datensatznummer |
250000784
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| Publikation (Nr.) |
 copernicus.org/tc-3-41-2009.pdf |
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| Zusammenfassung |
| The Wilkins Ice Shelf is situated on the Antarctic Peninsula, a region where
seven ice shelves disintegrated or retreated between 1995 and 2002. This
study combines various remote sensing datasets from Wilkins Ice Shelf, with
the aim of detecting its present and recent dynamics as well as recent
changes. The survey includes structural mapping, ERS-1/2 SAR interferometry
and analysis of ICESat GLAS ice surface elevation data. Ice front retreat
rates from 1986 to 2008 showed several distinct break-up events, including
one in February 2008, when 40% of a part of the ice shelf that connected two
islands broke off. Surface elevations have been used to study tidal effects,
crack formation and to estimate the ice thickness over the floating area.
The derived interferometric velocities cover the south-eastern part of the
ice shelf as well as major tributaries and reveal maximum inflow speeds of
up to 330 m a−1. We show that drainage of melt ponds into crevasses
were of no relevance for the break-up at Wilkins Ice Shelf. Buoyancy forces
caused rift formation before the break-up in February 2008. Additionally,
the evolution of failure zones of the order of tenths of kilometres in
length in pre-conditioned locations at ice rises is shown. Investigation of
the current (February 2009) situation shows that about 3100 km2 at the
Northern Wilkins Ice Shelf are endangered, however, there is no visible
signature that the remaining 8000 km2 are at risk. |
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