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An increase in crevasse extent, West Greenland: Hydrologic implications
Author(s) -
Colgan William,
Steffen Konrad,
McLamb W. Scott,
Abdalati Waleed,
Rajaram Harihar,
Motyka Roman,
Phillips Thomas,
Anderson Robert
Publication year - 2011
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2011gl048491
Subject(s) - crevasse , geology , physical geography , climatology , earth science , environmental science , geomorphology , geography
We compare high‐resolution 1985 and 2009 imagery to assess changes in crevasse extent in the Sermeq Avannarleq ablation zone, West Greenland. The area occupied by crevasses >2 m wide significantly increased (13 ± 4%) over the 24‐year period. This increase consists of an expansion of existing crevasse fields, and is accompanied by widespread changes in crevasse orientation (up to 45°). We suggest that a combination of ice sheet thinning and steepening are responsible for the increase in crevasse extent. We examine the potential impact of this change on the hydrology of the ice sheet. We provide a first‐order demonstration that moulin‐type drainage is more efficient in transferring meltwater fluctuations to the subglacial system than crevasse‐type drainage. As enhanced basal sliding is associated with meltwater “pulses”, an increase in crevasse extent can therefore be expected to result in a net decrease in basal sliding sensitivity. An increase in crevasse extent may also accelerate cryo‐hydrologic warming and enhance surface ablation.