Episodic propagation of a rift on the Amery Ice Shelf, East Antarctica

We investigate ice shelf rift propagation using a combination of GPS and seismic measurements near the tip of an active rift in the Amery Ice Shelf. These measurements reveal that propagation occurs in episodic bursts, which were identified based on swarms of seismicity accompanied by rapid rift wid...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Bassis, JN, Coleman, R, Fricker, HA, Minster, JB
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 2005
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Online Access:https://doi.org/10.1029/2004GL022048
http://ecite.utas.edu.au/33000
Description
Summary:We investigate ice shelf rift propagation using a combination of GPS and seismic measurements near the tip of an active rift in the Amery Ice Shelf. These measurements reveal that propagation occurs in episodic bursts, which were identified based on swarms of seismicity accompanied by rapid rift widening. The bursts last approximately 4 hours and are separated by 10-24 days. In between bursts, the rift widens at a rate comparable to that of ice shelf spreading. Comparison of automatic weather station data and tidal amplitudes show that the propagation bursts are not directly triggered by winds or tides, suggesting that rift propagation is driven by the background glaciological stress in the ice shelf. We show that the ice debris that partly fills the rift may play a role in controlling the rate of propagation. Copyright 2005 by the American Geophysical Union.