C043-0016
The subglacial lake at Russell Glacier catchment, West Greenland, that wasn’t there

Monday, 14 December 2020
Poster
Coen M Hofstede1, Olaf Eisen1, Diedrich Fritzsche2, Alun Hubbard II3, Niklas Neckel1, Rickard Pettersson4 and Frank Wilhelms1, (1)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Bremerhaven, Germany, (2)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Potsdam, Potsdam, Germany, (3)CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, UiT The Arctic University of Norway, Department of Geoscience, Tromsø, Norway, (4)Uppsala University, Uppsala, Sweden
Abstract:
Ground penetrating radar data from 2010, showed a 2 x 1 km2 flat area with increased reflectivity at the base of the western margin of the Greenland Ice Sheet, located in a local minimum of the hydropotential, 5.6 km northwest of a supraglacial lake that drained later that summer. In analogy to comparable features in Antarctica, the obvious initial interpretation of such a feature was the presence of a subglacial lake. In 2013 an additional seismic survey revealed an elongated lens-shaped body at the bottom of a subglacial 150 m deep trough at this position. Further seismic attribute analysis indicates that the lens shaped body does not represent a lake, but consists of stratified consolidated sediments. Liquid water seems to be present on the northern flank of the trough. The bed on the northern side of the trough consists of unconsolidated, possibly dilated, sediments, whereas on the southern side it consists of more consolidated material. Our interpretation is the trough is part of subglacial drainage network, for which the sediments on the northern side of the trough act as a reservoir that allow water storage.
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