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The internal deformation regime of Thwaites Glacier


McCormack, F and Warner, R and Treverrow, A and Seroussi, H, The internal deformation regime of Thwaites Glacier, Abstracts from the Twenty-Sixth Annual WAIS Workshop, 16-18 October 2019, Julian, California, U.S.A. (2019) [Conference Extract]

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Internal deformation is the main process controlling ice flow in ice shelves and in slow-moving regions of polar ice sheets where the ice is frozen to the bed. However, the contribution of internal deformation to flow in ice streams and fast-flowing regions is typically poorly constrained in ice sheet models. The current standard description of internal deformation used in most large-scale ice sheet models -- the Glen flow relation -- is limited by its failure to capture the tertiary flow of anisotropic ice that prevails in polar ice sheets. Here, we compare the flow regime of Thwaites Glacier as simulated by the Glen flow relation with a recent flow relation for anisotropic ice -- the ESTAR flow relation. With ESTAR, internal deformation contributes a factor of three times more to overall flow in the Thwaites Glacier ice streaming zone than when using the Glen flow relation. Using temperature dependent flow rate parameters with a stronger physical basis along with the ESTAR flow relation together provide the best match to observed surface velocities, but parameter selection and "matching" (i.e. via inversion) can significantly alter the predicted flow regime. Our results have implications for ice sheet evolution and stability, and may provide insight into an improved picture of basal sliding parameterizations.

Item Details

Item Type:Conference Extract
Keywords:ice sheet dynamics, deformation, Thwaites Glacier, Antarctica
Research Division:Earth Sciences
Research Group:Physical geography and environmental geoscience
Research Field:Glaciology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:McCormack, F (Dr Felicity McCormack)
UTAS Author:Warner, R (Dr Roland Warner)
UTAS Author:Treverrow, A (Dr Adam Treverrow)
ID Code:135523
Year Published:2019
Deposited By:Oceans and Cryosphere
Deposited On:2019-10-29
Last Modified:2019-10-29

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