SCEC Award Number 10182 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Development of semi-analytic models of time-dependent deformation due to earthquakes
Investigator(s)
Name Organization
Yuri Fialko University of California, San Diego
Other Participants Chris Takeuchi
Sylvain Barbot
SCEC Priorities A3, A11, C SCEC Groups CDM, FARM
Report Due Date 02/28/2011 Date Report Submitted N/A
Project Abstract
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Intellectual Merit We developed an efficient tool for forward modeling of postseismic deformation that does not
require custom-build meshes, yet is sufficiently general to honor
realistic boundary conditions and constitutive relationships. This tool was applied to investigate transient
deformation following the 1992 M7.3 Landers and the 1999
M7.1 Hector Mine earthquakes in the Mojave desert, Southern California. A joint inversion of the post-Landers and post-Hector Mine data favors a combination of poroelastic rebound (with ~3% reduction in the effective elastic moduli) and viscoelastic relaxation in the lower crust and upper mantle as the dominant mechanisms of transient deformation. The data neither exclude nor require a contribution of afterslip on a deep extension of the ruptured faults.
While the geodetic data cannot resolve fine details of the viscosity variations with depth, the best-fitting model suggests a weak lower crust and weak asthenosphere, separated by a ~20km-thick layer of strong upper mantle, consistent with the ``jelly sandwich'' model.
Broader Impacts This project supported an early career scientist (former graduate student Sylvain Barbot, now a postdoc at Caltech).
Exemplary Figure N/A
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