Grain-size-sensitive creep of ice in the 'dislocation creep' regime
Abstract
Deformation experiments on polycrystalline ice reveal multiple creep mechanisms, each of which can be described by a power law relationship of the form ė ∝ σnd-p , where ė is strain rate, σ differential stress, n the stress exponent, d grain size, and p the grain size exponent. For ice-sheet modeling, the rheological behavior of ice can be described by a composite flow law containing two parallel creep mechanisms - grain boundary sliding creep, which is grain size-sensitive, with n ~ 2 and p ~ 1.4, and dislocation creep, which is grain size-insensitive, with n ~ 4 and p = 0.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC015...03H
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0726 Ice sheets;
- CRYOSPHERE;
- 0798 Modeling;
- CRYOSPHERE;
- 3902 Creep and deformation;
- MINERAL PHYSICS