Seismic observations of transient subglacial water-flow beneath MacAyeal Ice Stream, West Antarctica

Authors

J. Paul Winberry, Central Washington University
Sridhar Anandakrishnan, Pennsylvania State University
Richard B. Alley, Pennsylvania State University

Department or Administrative Unit

Geological Sciences

Document Type

Article

Author Copyright

Copyright 2009 by the American Geophysical Union.

Publication Date

6-12-2009

Journal

Geophysical Research Letters

Abstract

New seismic observations of harmonic tremors beneath MacAyeal Ice Stream, West Antarctica are reported. Each of the two tremor events that we recorded during a six week period had sustained arrival of 3 Hz energy for approximately 10 minutes. During that time the source location migrated a few kilometers. The harmonic nature of the tremors is interpreted as the result of resonance in subglacial water-filled cracks and conduits. The duration, monochromatic nature, and movement of the tremor indicate that the source mechanism is likely flow in the subglacial water system resulting from the discharge from a small subglacial lake. Our results suggest that the subglacial water system produces repeated, small outburst floods, with possible implications for ice-stream dynamics.

Comments

This article was originally published in Geophysical Research Letters. The full-text article from the publisher can be found here.

Recommended Citation

Winberry, J. P., S. Anandakrishnan, and R. B. Alley (2009), Seismic observations of transient subglacial water-flow beneath MacAyeal Ice Stream, West Antarctica, Geophys. Res. Lett., 36, L11502, doi:10.1029/2009GL037730.