Tidally controlled stick-slip discharge of a West Antarctic ice.
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.
Bindschadler
Robert A
RA
Ocean and Ice Branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Robert.A.Bindschadler@nasa.gov
King
Matt A
MA
Alley
Richard B
RB
Anandakrishnan
Sridhar
S
Padman
Laurence
L