Investigating Elastic Heterogeneity and Topography Effects on 2010 Mw 7.2 El-Mayor Cucapah Earthquake Coseismic and Postseismic Deformation Using Finite Element Modelling and Space Geodetic Data
Abstract
The 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) earthquake, provides an important opportunity to investigate the complex dynamic processes of a transform plate boundary, where the response of the lithosphere to seismic events is influenced by the interaction among multiple faults, lithospheric heterogeneities, and topographic effects. Most existing studies represent the EMC area as an elastic half-space or layered structure and assume simplified fault configurations, which leads to considerable variability in the resultant fault slip models. To investigate the effects of fault geometry, surface topography and elastic heterogeneities, we developed a more realistic three-dimensional (3D) finite element model that includes multiple faults, a digital elevation model and material heterogeneities derived from seismic tomography studies. We first assess how well recently published fault slip distributions, derived from analytical inversions, when applied to forward numerical models fit the GPS observations. We iteratively improve the input fault slip distribution by performing a series of inverse models using available coseismic surface geodetic deformation data as constraints. The goodness of fit of the modeled deformation field is then cross-checked against far-field, InSAR and optical geodetic data. Checkerboard tests with synthetic datasets were used to quantify the resolution of our results. In the second part we use the optimized fault slip distribution from our best numerical model to develop forward viscoelastic models. We examine different rheology models proposed for the region and investigate lithospheric rheological influence on observed postseismic deformation using available postseismic observations.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.T52C..03P
- Keywords:
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- 0545 Modeling;
- COMPUTATIONAL GEOPHYSICS;
- 0560 Numerical solutions;
- COMPUTATIONAL GEOPHYSICS;
- 1932 High-performance computing;
- INFORMATICS;
- 3275 Uncertainty quantification;
- MATHEMATICAL GEOPHYSICS