SCEC Award Number 17188 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Joint body wave-surface wave imaging of the Central California Seismic Project region
Investigator(s)
Name Organization
Clifford Thurber University of Wisconsin, Madison
Other Participants Dr. Peng Li
SCEC Priorities 3a, 1d, 3b SCEC Groups CCSP, Seismology, CXM
Report Due Date 06/15/2018 Date Report Submitted 12/07/2018
Project Abstract
The goal of our project is to contribute to the development of high-resolution compressional and shear wave velocity (Vp and Vs) models for the region of the SCEC Central California Seismic Project, a region termed the Central California Area (CCA) (Figure 1). The work we are carrying out involves several tasks. (Task 1) One is to merge our previous seismic velocity tomography datasets that cover different parts of the CCA, and integrate them to densely cover the entire CCA. These include both body-wave and surface-wave datasets, the latter from ambient noise. (Task 2) Another more time-consuming task is to further augment the existing datasets in order to provide improved spatial sampling of the region. A key part of this task is to substantially increase the number of S-wave arrivals in the body-wave dataset and expand the coverage of ambient noise correlation functions (ANCFs) for the surface-wave dataset. (Task 3) The final task is to carry out preliminary joint inversions of the enlarged body-wave and surface-wave datasets, and compare the resulting model to the SCEC CCA model.
Intellectual Merit The project has created datasets and compressional and shear velocity models for the Central California Area (CCA) that can be used to improve the current SCEC CCA model (CCA-06) and can provide an alternative model to the CCA-06 model for higher-frequency waveform simulations, respectively.
Broader Impacts An improved structural model for the CCA can contribute to improved assessment of ground-shaking hazards, especially in regard to the Diablo Canyon nuclear power plant.
Exemplary Figure Figure 3c. Representative cross-sections through our new joint-inversion Vs models compared to the SCEC CCA-06 Vs model. (a) Joint inversion Vs model cross-sections, 1D initial model. (b) SCEC CCA-06 Vs model cross-sections. (c) Joint inversion Vs model cross-sections, 3D initial model. Top row: profile 5-5'. Second row: profile 10-10'. Third row: profile 15-15'. Fourth row: profile 20-20'. Note that some apparent discontinuities in the 3D panels arise from interpolating from the N-S/E-W oriented grid in the joint inversion to SW-NE cross-sections.