Seismic Variability Study of Eastern Alaska/Aleutian Megathrust
Abstract
The Eastern Alaska/Aleutian megathrust has ruptured in a number of >M8.0 earthquakes in the 20th century on multiple segments, causing strong ground shaking and generating Pacific-wide trunamis. Seismic variability along the arc within the Semidi-Shumagin segments, considered locked and creeping sections respectively, may be attributable to structural variations in the megathrust. We placed eight seismometers (6 broadband and 2 short-period) throughout the Alaska peninsula for the summer of 2011 to both record local seismicity and to serve as an onshore component to the Langseth ALEUT cruise. We combine these data with data from selected stations of the Alaska Earthquake Information Center (AEIC) and the Alaska Volcano Observatory (AVO) to locate local seismicity, to define the megathrust boundary, and to develop a velocity model of the arc in this region. So far, ~550 events during the two-month period were located using P- and S-phases and a local velocity model. Data from OBS's deployed during the ALEUT cruise will improve accuracy of locations along the megathrust.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.T11A2533M
- Keywords:
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- 7230 SEISMOLOGY / Seismicity and tectonics;
- 7240 SEISMOLOGY / Subduction zones;
- 8104 TECTONOPHYSICS / Continental margins: convergent