Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2-2011

Journal or Book Title

Journal of Glaciology

Volume

57

Issue

201

First Page

77

Last Page

87

DOI

10.3189/002214311795306583

Abstract

The cold-based termini of polythermal glaciers are usually assumed to adhere strongly to an immobile substrate and thereby supply significant resistance to the flow of warm-based ice upglacier. This compressive environment is commonly thought to uplift basal sediment to the surface of the glacier by folding and thrust faulting. We present model and field evidence from the terminus of Storglacïaren, Sweden, showing that the cold margin provides limited resistance to flow from up-glacier. Ice temperatures indicate that basal freezing occurs in this zone at 10–1 – 10–2 ma–1, but model results indicate that basal motion at rates greater than 1 ma–1 must, nevertheless, persist there for surface and basal velocities to be consistent with measurements. Estimated longitudinal compressive stresses of 20–25 kPa within the terminus further indicate that basal resistance offered by the cold-based terminus is small. These results indicate that where polythermal glaciers are underlain by unlithified sediments, ice-flow trajectories and sediment transport pathways may be affected by subglacial topography and hydrology more than by the basal thermal regime.

Comments

This is a manuscript of an article in Journal of Glaciology 57 (2011): 77, doi:10.3189/002214311795306583. Posted with permission.

Copyright Owner

Peter L. Moore, et al

Language

en

File Format

application/pdf

Published Version

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