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Drainage from water‐filled crevasses along the margins of Jakobshavn Isbræ: A potential catalyst for catchment expansion
Author(s) -
Lampkin D. J.,
Amador N.,
Parizek B. R.,
Farness K.,
Jezek K.
Publication year - 2013
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
eISSN - 2169-9011
pISSN - 2169-9003
DOI - 10.1002/jgrf.20039
Subject(s) - crevasse , geology , bedrock , geomorphology , drainage , drainage basin , hydrology (agriculture) , drainage system (geomorphology) , geography , ecology , cartography , geotechnical engineering , biology
Saturated crevasses occur in local depressions within the shear margins of Jakobshavn Isbræ at inflections in the ice stream's flow direction. Spatio‐temporal variability of seven distinctive saturated crevasse groups was examined during the 2007 melt season. The area of saturated crevasses reached its maximum extent, ~1.8 km 2 , in early July, and remained largely constant until early August. Filling rates are correlated with regional melt production, while drainage rates are highly correlated with areal extent. Estimates on potential drainage volume from the largest crevasse system are ~9.23 × 10 −3 km 3 ± 2.15 × 10 −8 km 3 and ~ 4.92 × 10 −2 km 3 ± 3.58 × 10 −8 km 3 , respectively, over a 16 day interval and are more than required for a distributed basal hydrologic system across this area to temporarily flood bedrock obstacles believed to control basal sliding. Future drainage events, likely extending farther inland with warming, could result in enhanced lateral mass discharge into the ice stream, with implications for the dynamic evolution of the entire basin.