Near-surface flow in glaciers obeying Glen's law
In determining the gravity-driven flow of a glacier or ice sheet which obeys Glen's flow law, previous methods have predicted infinite longitudinal stress at the glacier's surface. This physically unacceptable occurrence is due to a break-down in the mathematical methods used to obtain the...
| Main Authors: | , |
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| Format: | Text |
| Language: | English |
| Published: |
1982
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1027.2504 http://qjmam.oxfordjournals.org/content/37/2/273.full.pdf |
| Summary: | In determining the gravity-driven flow of a glacier or ice sheet which obeys Glen's flow law, previous methods have predicted infinite longitudinal stress at the glacier's surface. This physically unacceptable occurrence is due to a break-down in the mathematical methods used to obtain the solution. Using the method of matched asymptotic expansions, the solution valid in the near-surface region of a steady-state glacier is determined. The size of the near-surface or boundary-layer region is found to be of order S1/n, where S = hJL is the assumed small ratio of the characteristic thickness and length of the ice sheet and n is the exponent in Glen's power law. The solution is obtained for ice sheets on both a steep and gentle base slope. The stress field in the near-surface region is obtained and we find that the boundary layer does not significantly affect the surface velocities or the glacier profile. 1. |
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