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Dynamic (in)stability of Thwaites Glacier, West Antarctica
Author(s) -
Parizek B. R.,
Christianson K.,
Anandakrishnan S.,
Alley R. B.,
Walker R. T.,
Edwards R. A.,
Wolfe D. S.,
Bertini G. T.,
Rinehart S. K.,
Bindschadler R. A.,
Nowicki S. M. J.
Publication year - 2013
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
eISSN - 2169-9011
pISSN - 2169-9003
DOI - 10.1002/jgrf.20044
Subject(s) - geology , ice tongue , ice shelf , ice stream , glacier , bedrock , accumulation zone , ice divide , ice sheet , glacier terminus , lead (geology) , glacier morphology , cryosphere , thinning , geomorphology , oceanography , sea ice , geography , forestry
Thwaites Glacier, West Antarctica, has the potential to directly contribute ∼1 m to sea level and currently is losing mass and thinning rapidly. Here, we report on regional results for the Sea‐level Response to Ice Sheet Evolution (SeaRISE) experiments and investigate the impact of i) spatial resolution within existing data sets, ii) grounding‐zone processes, and iii) till rheology on the dynamics of this outlet glacier. In addition to the SeaRISE data sets, we use detailed aerogeophysical and satellite data from Thwaites Glacier as input to a coupled ice stream/ice‐shelf/ocean‐plume model that includes oceanic influences across a several kilometers wide grounding zone suggested by new, high‐resolution data. Our results indicate that the ice tongue provides limited stability, and that while future atmospheric warming will likely add mass to the surface of the glacier, strong ice stream stabilization on bedrock highs narrower than the length of the grounding zone may be ephemeral if circulating waters substantially reduce basal resistance and enhance melting beneath grounded ice within this zone. However, we find that stability is significantly enhanced by effectively plastic till beds. Accurate projections of future sea level change relies on correct understanding of the till rheology as well as local basal processes near the grounding line.