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A slow slip event in the south central Alaska Subduction Zone and related seismicity anomaly
Author(s) -
Wei Meng,
McGuire Jeffrey J.,
Richardson Eliza
Publication year - 2012
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 - 10.1029/2012gl052351
Subject(s) - induced seismicity , geology , seismology , subduction , slip (aerodynamics) , aftershock , global positioning system , episodic tremor and slip , geodesy , tectonics , physics , thermodynamics , telecommunications , computer science
We detected a slow slip event in the south central Alaska Subduction Zone by analyzing continuous GPS data from the Plate Boundary Observatory (PBO) network. The slow slip event started in early 2010 at a depth of 35 km beneath the Cook Inlet, near the down‐dip end of the locked zone, and is ongoing as of November 2011 with an accumulated magnitude of M w 6.9. Analysis of the earthquake catalog in the same area using the stochastic Epidemic Type Aftershock Sequence model (ETAS) shows a small but detectable seismicity increase during the slow slip event. We also find a change in seismicity rate around 1998, that may suggest an earlier slow slip event in the same region. Slow slip events in Alaska appear more widespread than previously thought but have remained undetected due to their long durations, the time intervals between them, and the limited time records from the continuous GPS.