The seismic cycle in the area of the 2011 M_w9.0 Tohoku-Oki earthquake
- Creators
- Perfettini, H.
- Avouac, J. P.
Abstract
We model seismic and aseismic slip on the Japan megathrust in the area of the M_w9.0, 2011 Tohoku-Oki earthquake based on daily time series from 400 GPS stations of the GEONET network and campaign measurements of six sea floor displacements. The coseismic and postseismic slip distributions are inverted simultaneously using principal component analysis-based inversion method (PCAIM). Exploring a wide range of boundary conditions and regularization constraints, we found the coseismic slip distribution to be quite compact with a peak slip between 30 and 50 m near the trench. Our model shows deep afterslip fringing the downdip edge of the coseismic rupture but also a dominant zone of shallow afterslip. Afterslip over the first 279 days following the main shock represents about 40% of the coseismic moment. We compare the coseismic and postseismic models with an interseismic coupling model derived from inland and sea bottom measurements determined in a self-consistent manner. Assuming that seismic and aseismic slip had to match the long-term slip rate along the megathrust, the recurrence time of M_w9.0 earthquakes is estimated to 100–300 years, while historical and paleotsunami records suggest a return period more of the order of 1000 years. The discrepancy is smaller if the shallower portion of the megathrust is assumed to produce both aseismic slip, as the afterslip model suggests, and seismic slip during occasional large tsunamigenic earthquakes.
Additional Information
© 2014 American Geophysical Union. Received 23 September 2013; Accepted 31 March 2014; Accepted article online 3 April 2014; Published online 27 May 2014. We thank Michiko Onogaki for providing the GEONET data, Brendan Meade for providing the interseismic velocities of Loveless and Meade [2010], Shinzaburo Ozawa, Mohamed Chlieh, Hiroo Kanamori, Michael Bevis, Erwan Pathier, and Michel Bouchon for useful discussions. We thank Tom Parson, Marcos Moreno and an anonymous reviewer for their constructive reviews that really helped improving the manuscript. Some of the figures of this paper have been done using GMT (http://gmt.soest.hawaii.edu/). This is Tectonics Observatory contribution #260.Attached Files
Published - jgrb50636.pdf
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Additional details
- Alternative title
- The seismic cycle in the area of the 2011 Mw9.0 Tohoku-Oki earthquake
- Eprint ID
- 47483
- Resolver ID
- CaltechAUTHORS:20140724-154902013
- Created
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2014-07-24Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Caltech Tectonics Observatory, Seismological Laboratory, Division of Geological and Planetary Sciences
- Other Numbering System Name
- Caltech Tectonics Observatory
- Other Numbering System Identifier
- 260