Document Type

Article

Publication Version

Published Version

Publication Date

12-2010

Journal or Book Title

Journal of Geophysical Research: Earth Surface

Volume

115

Issue

F4

First Page

1

Last Page

14

DOI

10.1029/2010JF001666

Abstract

Here we report results of water pressure pulse studies conducted at Storglaciären (Sweden) and West Washmawapta Glacier (British Columbia, Canada). Comparison of pressure pulse records with meteorological conditions at Storglaciären indicates that several periods of increased basal slip activity observed during a 10 day interval of summer 2008 were due to precipitation loading of the glacier surface, rather than to infiltration of surface water to the glacier bed; this indicates that the glacier bed was close to the failure strength for much of this interval. Pressure pulse magnitudes for the two glaciers were well-fit by power law distributions similar to those earlier observed at Trapridge Glacier (and similar in form to the Gutenberg-Richter relationship commonly used in seismology), suggesting that the mechanical processes that give rise to these distributions are robust features of soft-bedded glaciers. In contrast, interevent time distributions for both glaciers diverge from those observed at Trapridge Glacier for short recurrence intervals, suggesting that the factors that govern the rate at which these processes occur differ between glaciers. An examination of pressure pulse characteristics at West Washmawapta Glacier indicates that the establishment of a basal drainage system in summer 2008 resulted in increased stability and reduced sensitivity to meltwater input, suggesting that common assumptions about the relationship between meltwater production and ice flow are oversimplified. These results demonstrate that water pressure pulse observations can provide valuable insight into the dynamics of soft-bedded glaciers.

Comments

This article is from Journal of Geophysical Research: Earth Surface 115 (2010): art. F04025, doi:10.1029/2010JF001666. Posted with permission.

Copyright Owner

American Geophysical Union

Language

en

File Format

application/pdf

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