Publication Date:
2013-02-26
Description:
[1] 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 datasets, 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 changerelies on correct understanding of the till rheology as well as local basal processes near the grounding line.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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