A major West Antarctic ice stream discharges by sudden and brief periods of very rapid motion paced by oceanic tidal oscillations of about 1 meter. Acceleration to speeds greater than 1 meter per hour and deceleration back to a stationary state occur in minutes or less. Slip propagates at approximately 88 meters per second, suggestive of a shear wave traveling within the subglacial till. A model of an episodically slipping friction-locked fault reproduces the observed quasi-periodic event timing, demonstrating an ice stream's ability to change speed rapidly and its extreme sensitivity to subglacial conditions and variations in sea level.

Item Type:	Refereed Article
Keywords:	Acceleration; Deceleration; Friction; Ocean engineering; Oscillations; Shear waves; Tidal oscillations; Ice; ice; ice stream; sea level; stick-slip; tidal cycle; acceleration; Antarctica; article; calculation; dynamics; motion; ocean environment
Research Division:	Earth Sciences
Research Group:	Physical geography and environmental geoscience
Research Field:	Physical geography and environmental geoscience not elsewhere classified
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the earth sciences
UTAS Author:	King, MA (Professor Matt King)
ID Code:	81798
Year Published:	2003
Web of Science® Times Cited:	179
Deposited By:	Geography and Environmental Studies
Deposited On:	2013-01-08
Last Modified:	2013-01-08
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