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Bathymetry data reveal glaciers vulnerable to ice‐ocean interaction in Uummannaq and Vaigat glacial fjords, west Greenland
Author(s) -
Rignot E.,
Fenty I.,
Xu Y.,
Cai C.,
Velicogna I.,
Cofaigh C. Ó,
Dowdeswell J. A.,
Weinrebe W.,
Catania G.,
Duncan D.
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 - 10.1002/2016gl067832
Subject(s) - fjord , geology , glacier , sill , bathymetry , oceanography , glacial period , iceberg , tidewater glacier cycle , glacier morphology , seafloor spreading , ice sheet , greenland ice sheet , continental shelf , geomorphology , cryosphere , sea ice , ice stream , ice calving , pregnancy , geochemistry , lactation , biology , genetics
Abstract Marine‐terminating glaciers play a critical role in controlling Greenland's ice sheet mass balance. Their frontal margins interact vigorously with the ocean, but our understanding of this interaction is limited, in part, by a lack of bathymetry data. Here we present a multibeam echo sounding survey of 14 glacial fjords in the Uummannaq and Vaigat fjords, west Greenland, which extends from the continental shelf to the glacier fronts. The data reveal valleys with shallow sills, overdeepenings (>1300 m) from glacial erosion, and seafloor depths 100–1000 m deeper than in existing charts. Where fjords are deep enough, we detect the pervasive presence of warm, salty Atlantic Water (AW) (>2.5°C) with high melt potential, but we also find numerous glaciers grounded on shallow (<200 m) sills, standing in cold (<1°C) waters in otherwise deep fjords, i.e., with reduced melt potential. Bathymetric observations extending to the glacier fronts are critical to understand the glacier evolution.