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Extensive winter subglacial water storage beneath the Greenland Ice Sheet
Author(s) -
Chu Winnie,
Schroeder Dustin M.,
Seroussi Helene,
Creyts Timothy T.,
Palmer Steven J.,
Bell Robin E.
Publication year - 2016
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 - 10.1002/2016gl071538
Subject(s) - geology , meltwater , greenland ice sheet , ice stream , ice sheet , glacier , bedrock , glacier morphology , geomorphology , ice divide , cryosphere , depth sounding , ice tongue , rock glacier , physical geography , hydrology (agriculture) , climatology , oceanography , sea ice , geography , geotechnical engineering
Abstract Surface meltwater that reaches the base of the Greenland Ice Sheet exerts a fundamental impact on ice flow, but observations of catchment‐wide movement and distribution of subglacial water remain limited. Using radar‐sounding data from two seasons, we identify the seasonal distribution of subglacial water in western Greenland. Our analysis provides evidence of widespread subglacial water storage beneath Greenland in the wintertime. The winter storage is located primarily on bedrock ridges with higher bed elevations in excess of 200 m. During the melt season water moves to the subglacial troughs. This inverse relationship with topography indicates that the material properties of the glacier bed strongly influence subglacial drainage development. Both the spatial variations in bed properties and the initial state of the subglacial hydrology system at the start of the melt season lead to differing glacier dynamical responses to surface melting across the Greenland Ice Sheet.