SCEC Award Number 10092 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Sensitivity of modeled stressing and fault slip rates to lithosphere structure and rheology
Investigator(s)
Name Organization
Elizabeth Hearn University of British Columbia (Canada)
Other Participants Ali Vaghri
SCEC Priorities A3, A11, A SCEC Groups CDM
Report Due Date 02/28/2011 Date Report Submitted N/A
Project Abstract
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Intellectual Merit In 2010, my group continued its work on how rheological heterogeneities and viscoelastic relaxation influence GPS surface velocity fields (and hence inferred fault slip and stressing rates). My PhD student, Ali Vaghri, developed earthquake cycle models incorporating lateral rheological contrasts and multiple strike-slip faults. My own research addressed (1) earthquake cycles for faults with deep, viscous shear zones and (2) assessing when viscoelastic earthquake-cycle modeling is (or is not) required to infer fault slip rates from GPS velocity fields. This year, I also co-chaired workshops related to incorporating GPS data (and block model-inferred fault slip rates) into UCERF3. Taken together, this work aids in the interpretation of geodetic measurements of surface deformation in terms of subsurface processes, provides insight on the degree of complexity really required to adequately infer time-dependent seismic hazard, and highlights the importance of accurately representing fault system geometry at depth in deformation models.
Broader Impacts Understanding how to accurately model interseismic deformation and stress accumulation on active fault systems as economically as possible will expand the list of hypotheses we can test (e.g. different posited fault geometries). It could also make formal inversions for properties pertinent to seismic hazard (e.g. slip rates, stressing rates) possible - unthinkable for full-blown (heterogeneous, nonlinear) viscoelastic FE models. This is of obvious social importance because it allows us to refine PSHA in southern California.
I was on sabbatical this year, so I did not teach (hence, no benefits for teaching and learning at UBC).
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