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Estimating Ice Discharge at Greenland's Three Largest Outlet Glaciers Using Local Bedrock Uplift
Author(s) -
Hansen Karina,
Truffer Martin,
Aschwanden Andy,
Mankoff Kenneth,
Bevis Michael,
Humbert Angelika,
Broeke Michiel R.,
Noël Brice,
Bjørk Anders,
Colgan William,
Kjær Kurt H.,
Adhikari Surendra,
Barletta Valentina,
Khan Shfaqat A.
Publication year - 2021
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 - 10.1029/2021gl094252
Subject(s) - glacier , geology , thinning , slowdown , bedrock , rock glacier , glacier morphology , firn , ice stream , geomorphology , physical geography , climatology , cryosphere , sea ice , geography , political science , law , forestry
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.