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Surge at Basin 3 analysed using continuum and discrete ice models

Written by Thomas Zwinger.

The built-in inversion capabilities of Elmer/Ice have been used to determine the change of basal friction coefficients below the glacier at Basin 3, Austfonna, during the acceleration phase of its recent surge. This time series, showing the unplugging of the stagnant ice front, was made possible by a highly temporal and spatial resolved set of satellite observations. 

 

Observations also provided information on the crevasse field at the glacier, which was used to compare with the results obtained by the discrete element model, HiDEM, which was used to determine the instantaneous fractures as a reaction to the changing inverted basal friction. Identifying those crevasses that are deep enough to act as a path for surface water towards the bed and using a simplified hydraulic model, the possible mechanisms that lead to the surge of Basin 3 in early 2013 are discussed in this paper.

The picture shows the by Elmer/Ice computed basal sliding velocities as well as the flow path according to the hydraulic potential of water entering the deepest crevasses (red dots) that have been computed with HiDEM.

Read more: Gong, Y., Zwinger, T., Åström, J., Altena, B., Schellenberger, T., Gladstone, R., and Moore, J. C., 2018. Simulating the roles of crevasse routing of surface water and basal friction on the surge evolution of Basin 3, Austfonna ice cap. The Cryosphere, 12, 1563-1577, doi:10.5194/tc-12-1563-2018

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