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Seismic observations of transient subglacial water‐flow beneath MacAyeal Ice Stream, West Antarctica
Author(s) -
Winberry J. Paul,
Anandakrishnan Sridhar,
Alley Richard B.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl037730
Subject(s) - geology , ice stream , geomorphology , flow (mathematics) , denudation , geophysics , seismology , cryosphere , oceanography , tectonics , sea ice , geometry , mathematics
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.