Document Type

Article

Publication Title

Journal of Geophysical Research: Earth Surfaces

Publisher

American Geophysical Union

Publication Date

9-9-2015

Volume

120

Disciplines

Computer Sciences | Glaciology

Abstract

We use a new discretization technique to solve the higher-order thermomechanically coupled equations of glacier evolution. We find that under radially symmetric continuum equations, small perturbations in symmetry due to the discretization are sufficient to produce the initiation of non-symmetric thermomechanical instabilities which we interpret as ice streams, in good agreement with previous studies which have indicated a similar instability. We find that the inclusion of membrane stresses regularizes the size of predicted streams, eliminating the ill-posedness evident in previous investigations of ice stream generation through thermomechanical instability. Ice streams exhibit strongly irregular periodicity which is influenced by neighboring ice streams and the synoptic state of the ice stream. Ice streams are not always the same size but instead appear to follow a temperature-dependent distribution of widths that is robust to grid refinement. the morphology of the predicted ice streams corresponds reasonably well to extant ice streams in physically similar environments.

Keywords

ice sheet model; ice streams; thermofrictional instability; membrane stress; periodic time scales

DOI

10.1002/2015JF003499

Comments

An edited version of this paper was published by AGU. Copyright 2015 American Geophysical Union.

Rights

© 2015. American Geophysical Union.

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