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Article
Two Modes of Accelerated Glacier Sliding Related to Water
Geophysical Research Letters
  • J. T Harper
  • Neil Humphrey, University of Wyoming
  • W. T Pfeffer
  • B. Lazar
Document Type
Article
Publication Date
6-29-2007
Disciplines
Abstract
We present the first glacier-wide detailed measurement of basal effective pressure and related observations including bed separation to elucidate the role of water in sliding. The hard bedded glacier instrumented in our study exhibited two phases of accelerated sliding motion apparently driven by separate mechanisms. The first acceleration phase ( up to 5 fold increase in speed) was closely tied to an increase in bed separation. The faster second phase ( up to 9 fold increase in speed) was related to an unusually high level of connectivity of subglacial waters. We infer the first mode was related to cavity opening and the second mode was related to reduced ice contact with the bed. Glacier sliding over a hard bed is typically represented by sliding laws that include the effective basal pressure, but neither sliding phase was accompanied by a simultaneous decrease in local or regional effective pressure.
DOI
10.1029/2007GL030233
Comments
An edited version of this paper was published by AGU. Copyright 2007 American Geophysical Union.
Citation Information
J. T Harper, Neil Humphrey, W. T Pfeffer and B. Lazar. "Two Modes of Accelerated Glacier Sliding Related to Water" Geophysical Research Letters Vol. 34 Iss. 12 (2007)
Available at: http://works.bepress.com/neil_humphrey/7/