Perfettini, H. and Avouac, J.-P. (2007) Modeling afterslip and aftershocks following the 1992 Landers earthquake. Journal of Geophysical Research B, 112 (B7). Art. No. B07409 . ISSN 0148-0227 http://resolver.caltech.edu/CaltechAUTHORS:20101115-104352655
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One way to probe the rheology of the lithosphere and fault zones is to analyze the temporal evolution of deformation following a large earthquake. In such a case, the lithosphere responds to a known stress change that can be assessed from earthquake slip models constrained from seismology and geodesy. Here, we model the postseismic response of a fault zone that is assumed to obey a rate-strengthening rheology, where the frictional stress varies as aσ ln(ε), ε being the deformation rate and aσ > 0 a rheological parameter. The model is simple enough that these parameters can be estimated by inversion of postseismic geodetic data. We apply this approach to the analysis of geodetic displacements following the M_w 7.3, 1992, Landers earthquake. The model adjusts well the measured displacements and implies aσ ≈ 0.47–0.53 MPa. In addition, we show that aftershocks and afterslip follow the same temporal evolution and that the spatiotemporal distribution of aftershocks is consistent with the idea that they are driven by reloading of the seismogenic zone resulting from frictional afterslip.
|Additional Information:||© 2007 American Geophysical Union. Received 17 March 2006; revised 9 March 2007; accepted 4 April 2007; published 19 July 2007. We are very grateful to J. C. Savage and Y. Fialko for providing us with some of the materials used in this study. We thank Y. Fialko and A. Rubin for their constructive reviews which have really helped us to clarify some key assumptions of the model. We have also benefited from discussions with J.-P. Ampuero and S. Mazzotti. We thank H. G. Steele and E. Nadin for language corrections. Some of the figures in this paper were made using Generic Mapping Tools (GMT) [Wessel and Smith, 1998]. This work has been partially funded by IRD. This is Caltech Tectonics Observatory contribution 69.|
|Group:||Caltech Tectonics Observatory|
|Subject Keywords:||1992 Landers earthquake; afterslip; aftershocks; postseismic deformation; GPS|
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|Official Citation:||Perfettini, H., and J.-P. Avouac (2007), Modeling afterslip and aftershocks following the 1992 Landers earthquake, J. Geophys. Res., 112, B07409, doi:10.1029/2006JB004399.|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||15 Nov 2010 19:38|
|Last Modified:||26 Dec 2012 12:38|
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