glaciers; Greenland; ice discharge; ice loss; land uplift; surface mass balance; Dynamic thinning; Elastic displacements; Estimate dynamics; Global Navigation Satellite Systems; Ice discharges; Short term; Solid earth; Geophysics; Earth and Planetary Sciences (all); General Earth and Planetary Sciences
Abstract :
[en] We present a novel method to estimate dynamic ice loss of Greenland's three largest outlet glaciers: Jakobshavn Isbræ, Kangerlussuaq Glacier, and Helheim Glacier. We use Global Navigation Satellite System (GNSS) stations attached to bedrock to measure elastic displacements of the solid Earth caused by dynamic thinning near the glacier terminus. When we compare our results with discharge, we find a time lag between glacier speedup/slowdown and onset of dynamic thinning/thickening. Our results show that dynamic thinning/thickening on Jakobshavn Isbræ occurs 0.87 ± 0.07 years before speedup/slowdown. This implies that using GNSS time series we are able to predict speedup/slowdown of Jakobshavn Isbræ by up to 10.4 months. For Kangerlussuaq Glacier the lag between thinning/thickening and speedup/slowdown is 0.37 ± 0.17 years (4.4 months). Our methodology and results could be important for studies that attempt to model and understand mechanisms controlling short-term dynamic fluctuations of outlet glaciers in Greenland.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Hansen, Karina ; DTU Space, Technical University of Denmark, Kongens Lyngby, Denmark
Truffer, Martin ; Geophysical Institute, University of Alaska Fairbanks, Fairbanks, United States
Aschwanden, Andy ; Geophysical Institute, University of Alaska Fairbanks, Fairbanks, United States ; Department of Glaciology and Climate, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
Mankoff, Kenneth ; Department of Glaciology and Climate, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
Bevis, Michael ; School of Earth Sciences, Ohio State University, Colombus, United States
Humbert, Angelika ; Alfred-Wegener-Institut Helmholtz Zentrum für Polar- und Meeresforschung, Germany and University of Bremen, Bremerhaven, Germany
van den Broeke, Michiel R. ; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, Netherlands
Noël, Brice ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie ; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, Netherlands
Bjørk, Anders; Department of Geosciences and Natural Resources, University of Copenhagen, Copenhagen, Denmark
Colgan, William ; Department of Glaciology and Climate, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
Kjær, Kurt H.; Centre for GeoGenetics, Globe Institute, University of Copenhagen, Copenhagen, Denmark
Adhikari, Surendra ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States
Barletta, Valentina; DTU Space, Technical University of Denmark, Kongens Lyngby, Denmark
Khan, Shfaqat A. ; DTU Space, Technical University of Denmark, Kongens Lyngby, Denmark
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