Geodesy and Gravity/Tectonophysics
Modeling afterslip and aftershocks following the 1992 Landers earthquake
Article first published online: 19 JUL 2007
Copyright 2007 by the American Geophysical Union.
Journal of Geophysical Research: Solid Earth (1978–2012)
Volume 112, Issue B7, July 2007
How to Cite
2007), Modeling afterslip and aftershocks following the 1992 Landers earthquake, J. Geophys. Res., 112, B07409, doi:10.1029/2006JB004399., and (
- Issue published online: 19 JUL 2007
- Article first published online: 19 JUL 2007
- Manuscript Accepted: 4 APR 2007
- Manuscript Revised: 9 MAR 2007
- Manuscript Received: 17 MAR 2006
- 1992 Landers earthquake;
- postseismic deformation;
 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(), 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 Mw7.3, 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.