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| Titel |
Ice velocity and ice elevation changes at Fleming Glacier, Antarctic Peninsula |
| VerfasserIn |
Anja Wendt, Francisca Bown, Andrés Rivera, Rodrigo Zamora, Gino Casassa, Claudio Bravo, Mathias Fritsche, Reinhard Dietrich |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250056437
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| Zusammenfassung |
| The Antarctic Peninsula is one of the hot spots in climate warming with air temperature
trends well above the global average. Ice shelves in the region are known to have
retreated and collapsed during the last decades with the retreat of Wordie Ice Shelf in
the 1980s as one of the first well-documented events. Since then, the retreat has
continued reducing the original surface area of about 2000 km2 in the 1960s to less than
100 km2 in 2010 that still survive as two small and isolated ice tongues. Fleming
Glacier, the largest glacier draining into Wordie Bay, has lost all its floating part and
its glacier front is situated upstream of its 1996 grounding line. We investigate
Fleming Glacier in order to determine how the change in the buttressing force at its
terminus affects the flow behaviour. Ice velocities at the lower reaches of the glacier
were determined using image correlation techniques applied to optical and radar
satellite data acquired between 1989 and 2010. The results show an acceleration of the
glacier of between 30 and 60 % within this time span. During the summer season
2008/2009 GPS measurements were conducted at an altitude of about 900 m a.s.l. and a
distance of 40 km from the glacier front where velocity data from the 1970s are
available. The data demonstrate that acceleration also affects the upper reaches. A
detailed analysis of 10 month of continuous GPS data reveals an acceleration signal
even within this short time period. A comparison of airborne laser scanning data
acquired in 2004 and 2008 revealed a surface lowering all along a longitudinal
profile starting at an elevation of 1100 m down to the ice front where maximum
elevation change rates of -4.1 m per year were detected. Elevation trends determined
from ICESat data confirm the former result. In summary, negative ice elevation
trends together with the acceleration of the ice flow indicate that Fleming Glacier
has not yet reached a new equilibrium and is still losing mass due to enhanced ice
flow. |
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