SCEC Award Number 20040 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title Incorporation of Salton Sea Imaging Project data into joint inversions for Vp and Vs models and model assessment via wavefield simulations
Name Organization
Clifford Thurber University of Wisconsin, Madison
Other Participants Ben Heath
SCEC Priorities 4a, 3a, 3b SCEC Groups Seismology, CXM, CS
Report Due Date 03/15/2021 Date Report Submitted 05/05/2021
Project Abstract
Our current SCEC project, award #20040, involves application of joint body wave-surface wave tomography to southern California using the joint inversion code of Fang et al. (2016) with a greatly expanded dataset compared to previous studies. We use multiple starting models, followed by evaluation of the tomographically updated models via wavefield simulation. Specifically, the inversion results and the starting and final models are evaluated for their relative ability to fit waveforms for selected regional earthquakes, using simulations done with SPECFEM3D. The overall goal of our work is to assess whether the combination of (1) assembling an enlarged dataset, taking particular advantage of data from the Salton Sea Imaging Project (SSIP; Han et al., 2016), and (2) applying a joint body wave-surface wave inversion code can (3) produce a seismic velocity model that better fits regional waveforms than the starting models for a set of moderate-sized earthquakes.
Intellectual Merit The research endeavors to improve the seismic velocity models that are used for wavefield simulations for prediction of ground motion during future earthquakes. Our work has employed a novel joint body wave-surface wave inversion method.
Broader Impacts By improving the seismic velocity models that are used for wavefield simulations for prediction of ground motion during future earthquakes, the accuracy of the simulations will be improved. Because such simulations are used for seismic hazard assessment, the hazard assessment will in turn be improved.
Exemplary Figure Figure 2. Map-view slices through (left) the Fang et al. (2016) starting model compared to (right) the joint inversion result. (a-b) Vp. (c-d) Vs.

Fang, H., H. Zhang, H. Yao, A. Allam, D. Zigone, Y. Ben-Zion, C. Thurber, and R. D. van der Hilst (2016), A new algorithm for three-dimensional joint inversion of body-wave and surface-wave data and its application to the Southern California Plate Boundary Region, J. Geophys. Res. Solid Earth, 121, doi:10.1002/2015JB012702.