Consistent generation of ice-streams via thermo-viscous instabilities modulated by membrane stresses

Hindmarsh, Richard C.A. ORCID: https://orcid.org/0000-0003-1633-2416. 2009 Consistent generation of ice-streams via thermo-viscous instabilities modulated by membrane stresses. Geophysical Research Letters, 36 (6), L06502. 6, pp. 10.1029/2008GL036877

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Abstract/Summary

Accurate computation of ice-stream location and dynamics is a key aspiration for theoretical glaciology. Ice-sheet models with thermo-viscous coupling have been shown to exhibit stream-like instabilities using shallow-ice approximation mechanics, but the location and width of these streams depends on the numerical implementation and are not unique. We present results from thermo-viscously coupled ice-sheet models incorporating membrane stresses. Spontaneous generation of fast-flowing linear features still occurs under certain parameter regimes, with computed stream widths between 20 km to 100 km, comparable with observations. These features are maintained as the grid-size is decreased. The thermo-viscous feedback mechanism that generates ice-streams under the shallow ice approximation still operates, now selecting a unique stream size. Computations of thermo-viscous ice flows should include membrane stresses when the bed is approximately flat, e. g. parts of Antarctica and former ice-sheets of the Northern hemisphere. Previous calculations of spontaneous ice-stream generation using the shallow ice approximation should be reassessed. Citation: Hindmarsh, R. C. A. (2009), Consistent generation of ice-streams via thermo-viscous instabilities modulated by membrane stresses, Geophys. Res. Lett., 36, L06502, doi:10.1029/2008GL036877.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1029/2008GL036877
Programmes:	BAS Programmes > Global Science in the Antarctic Context (2005-2009) > Glacial Retreat in Antarctica and Deglaciation of the Earth System
ISSN:	0094-8276
Additional Keywords:	ice stream, instability
NORA Subject Terms:	Glaciology
Date made live:	02 Nov 2010 14:00 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/11030

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1029/2008GL036877

Programmes:

BAS Programmes > Global Science in the Antarctic Context (2005-2009) > Glacial Retreat in Antarctica and Deglaciation of the Earth System

ISSN:

0094-8276

Additional Keywords:

ice stream, instability

NORA Subject Terms:

Glaciology