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Lookup NU author(s): Professor Matt King
The downstream portion of Whillans Ice Stream, West Antarctica, moves primarily by stick-slip motion. The observation of stick-slip motion suggests that the bed is governed by velocity-weakening physics and that the basal physics is more unstable than suggested by laboratory studies. The stick-slip cycle of Whillans Ice Plain exhibits substantial variability in both the duration of sticky periods and in slip magnitude. To understand this variability, we modeled the forces acting on the ice stream during the stick phase of the stick-slip cycle. The ocean tides introduce changes in the rate at which stress is applied to the ice plain. Increased loading rates promote earlier failure and vice versa. Results show that the bed of Whillans Ice Stream strengthens over time (healing) during the quiescent intervals in the stick-slip cycle, with the bed weakening during slip events. The time-dependent strengthening of the ice plain bed following termination of slip events indicates that the strength of the bed may vary by up to 0.35 kPa during the course of a single day.
Author(s): Winberry JP, Anandadrishnan S, Alley RB, Bindschadler R, King MA
Publication type: Article
Publication status: Published
Journal: Journal of Geophysical Research: Earth Surface
Year: 2008
Volume: 114
Issue: 1
Date deposited: 12/07/2010
ISSN (print): 0148-0227
Publisher: American Geophysical Union
URL: http://dx.doi.org/10.1029/2008JF001035
DOI: 10.1029/2008JF001035
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