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Basal mechanics of ice streams: Insights from the stick-slip motion of Whillans Ice Stream, West Antarctica
journal contribution
posted on 2023-05-17, 15:25 authored by Winberry, JP, Anandakrishnan, S, Alley, RB, Bindschadler, RA, Matt KingMatt KingThe 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 Whillaňs 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. Copyright 2009 by the American Geophysical Union.
History
Publication title
Journal of Geophysical Research: Earth SurfaceVolume
114Issue
F1Article number
F01016Number
F01016Pagination
1-11ISSN
0148-0227Department/School
School of Geography, Planning and Spatial SciencesPublisher
Wiley-Blackwell Publishing, Inc.Place of publication
USARights statement
Copyright 2009 American Geophysical UnionRepository Status
- Restricted