The shallow shelf approximation as a “sliding law” in a thermomechanically coupled ice sheet model
نویسندگان
چکیده
The shallow shelf approximation is a better “sliding law” for ice sheet modeling than those sliding laws in which basal velocity is a function of driving stress. The shallow shelf approximation as formulated by Schoof [2006a] is well-suited to this use. Our new thermomechanically coupled sliding scheme is based on a plasticity assumption about the strength of the saturated till underlying the ice sheet in which the till yield stress is given by a Mohr-Coulomb formula using a modeled pore water pressure. Using this scheme, our prognostic whole ice sheet model has convincing ice streams. Driving stress is balanced in part by membrane stresses, the model is computable at high spatial resolution in parallel, it is stable with respect to parameter changes, and it produces surface velocities seen in actual ice streams.
منابع مشابه
Shallow shelf approximation as a ‘‘sliding law’’ in a thermomechanically coupled ice sheet model
[1] The shallow shelf approximation, a balance of membrane stresses for ice flow, is an effective ‘‘sliding law’’ for ice sheet modeling. Our use of it as a sliding law becomes a standard model for ice stream flow when the sliding velocity is large (100 m a 1 and faster). Following Schoof (2006a), we describe the basal resistance as plastic till for which the yield stress is given by a Mohr-Cou...
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