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| Titel |
Cascading water underneath Wilkes Land, East Antarctic ice sheet, observed using altimetry and digital elevation models |
| VerfasserIn |
T. Flament, E. Berthier, F. Remy |
| 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. 2 ; Nr. 8, no. 2 (2014-04-15), S.673-687 |
| Datensatznummer |
250116094
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| Publikation (Nr.) |
 copernicus.org/tc-8-673-2014.pdf |
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| Zusammenfassung |
| We describe a major subglacial lake drainage close to the ice divide in
Wilkes Land, East Antarctica, and the subsequent cascading of water
underneath the ice sheet toward the coast. To analyse the event, we combined
altimetry data from several sources and subglacial topography. We estimated
the total volume of water that drained from Lake CookE2 by differencing
digital elevation models (DEM) derived from ASTER and SPOT5 stereo imagery
acquired in January 2006 and February 2012. At 5.2 ± 1.5 km3, this
is the largest single subglacial drainage event reported so far in
Antarctica. Elevation differences between ICESat laser altimetry spanning
2003–2009 and the SPOT5 DEM indicate that the discharge started in November
2006 and lasted approximately 2 years. A 13 m uplift of the surface,
corresponding to a refilling of about 0.6 ± 0.3 km3, was observed
between the end of the discharge in October 2008 and February 2012. Using
the 35-day temporal resolution of Envisat radar altimetry, we monitored the
subsequent filling and drainage of connected subglacial lakes located
downstream of CookE2. The total volume of water traveling within the
theoretical 500-km-long flow paths computed with the BEDMAP2 data set is
similar to the volume that drained from Lake CookE2, and our
observations suggest that most of the water released from Lake CookE2
did not reach the coast but remained trapped underneath the ice sheet. Our
study illustrates how combining multiple remote sensing techniques allows
monitoring of the timing and magnitude of subglacial water flow beneath the
East Antarctic ice sheet. |
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