Tidally Controlled Stick-Slip Discharge of a West Antarctic Ice

• Published in: Science
• Main Authors: Bindschadler, Robert A., King, Matt A., Alley, Richard B., Anandakrishnan, Sridhar, Padman, Laurence
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 2003
• Subjects: Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1126/science.1087231; https://www.science.org/doi/pdf/10.1126/science.1087231

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.