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Rapid retreat and acceleration of Helheim Glacier, east Greenland
Author(s) -
Howat I. M.,
Joughin I.,
Tulaczyk S.,
Gogineni S.
Publication year - 2005
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 - 10.1029/2005gl024737
Subject(s) - geology , glacier , thinning , front (military) , glacier mass balance , acceleration , ice stream , tidewater glacier cycle , glacier morphology , ice calving , geodesy , physical geography , geomorphology , climatology , oceanography , sea ice , cryosphere , geography , physics , classical mechanics , pregnancy , lactation , biology , forestry , genetics
A significant amount of the measured coastal thinning of the Greenland ice sheet may be due to recent acceleration of outlet glaciers. Using remote sensing, we measured two major periods of speedup on Helheim Glacier between 2000 and 2005 that increased peak speeds from approximately 8 to 11 km/yr. These speedups coincided with rapid retreats of the calving front, totaling over 7.5 km. The glacier also thinned by over 40 m from 2001 to 2003. Retreat of the ice front appears to decrease resistance to flow and concentrates the gravitational driving force over a smaller area. Farther up‐glacier, acceleration may be a delayed response to surface draw‐down and steepening of the glacier's main trunk. If the 2005 speedup also produces strong thinning, then much of the glacier's main trunk may un‐ground, leading to further retreat.