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| Titel |
Ice tectonic deformation during the rapid in situ drainage of a supraglacial lake on the Greenland Ice Sheet |
| VerfasserIn |
S. H. Doyle, A. L. Hubbard, C. F. Dow, G. A. Jones, A. Fitzpatrick, A. Gusmeroli, B. Kulessa, K. Lindback, R. Pettersson, J. E. Box |
| 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 ; 7, no. 1 ; Nr. 7, no. 1 (2013-01-28), S.129-140 |
| Datensatznummer |
250017407
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| Publikation (Nr.) |
 copernicus.org/tc-7-129-2013.pdf |
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| Zusammenfassung |
| We present detailed records of lake discharge, ice motion and passive
seismicity capturing the behaviour and processes
preceding, during and following the rapid drainage of
a 4 km2 supraglacial lake through 1.1-km-thick ice
on the western margin of the Greenland Ice Sheet. Peak discharge
of 3300 m3 s−1 coincident with
maximal rates of vertical uplift indicates that surface water accessed the ice–bed interface causing
widespread hydraulic separation and enhanced basal motion. The
differential motion of four global positioning system (GPS) receivers located around the lake record the
opening and closure of the fractures through which the lake drained. We hypothesise that the majority
of discharge occurred through a 3-km-long fracture with a peak width
averaged across its wetted length of 0.4 m. We argue that the
fracture's kilometre-scale length allowed rapid discharge to be achieved by
combining reasonable water velocities with sub-metre fracture widths. These
observations add to the currently limited knowledge of in situ supraglacial
lake drainage events, which rapidly deliver large volumes of water to the
ice–bed interface. |
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