The Role of Lateral and Vertical Shear in Tributary Flow toward a West Antarctic Ice Stream

Authors

Christina L. Hulbe, Portland State UniversityFollow
Weili WangFollow
Ian R. JoughinFollow
Martin J. Siegert

Sponsor

This work was supported by U.S. National Science Foundation grant OPP-0105308 and the NASA IceSat project.

Published In

Annals of Glaciology

Document Type

Article

Publication Date

1-1-2003

Subjects

Ice sheets -- Antarctica, Glaciers -- Antarctica, Ice sheets -- Mathematical models, Ice shelves -- Antarctica

Abstract

Narrow lateral shear margins are the most distinctive visual feature of the West Antarctic ice streams. Large shear stresses within these layers support the majority of the gravitational driving stress within a fast-flowing ice stream.The present contribution looks upstream, to the tributaries that feed ice-stream onsets, and considers the effects of both horizontal and vertical shear on their flow. Numerical and direct simulations of vertical and horizontal shear are used.Vertical shear, simulated using an anisotropic flow law, is of particular interest.We conclude that by isolating overlying ice from large-amplitude variations in bed elevation -vertical shear margins - play an important role in sustaining relatively rapid tributary flow.

Description

Originally appeared in Annals of Glaciology, published by the International Glaciological Society. Article can be found at http://www.igsoc.org/annals/

DOI

10.3189/172756403781816194

Persistent Identifier

http://archives.pdx.edu/ds/psu/8433

Citation Details

Hulbe, C.L., W.L. Wang, I. Joughin, and M.J. Siegert, 2003, The role of lateral and vertical shear in tributary flow toward a West Antarctic ice stream, Annals of Glaciology, 36, 244-250.