Beyond 1 Hz: Double-difference active source adjoint tomography of Salton Trough

Rasheed Ajala, Patricia Persaud, & Alan Juarez

Submitted August 16, 2021, SCEC Contribution #11547, 2021 SCEC Annual Meeting Poster #012

A decade after the Salton Seismic Imaging Project (SSIP), we have initiated the overdue high-frequency adjoint tomography of Salton Trough crust. We are mainly motivated by previous results showing that embedding 3D travel time Earth models developed using SSIP data into the SCEC community velocity models can significantly improve low-frequency waveform predictions. To increase the computational feasibility of the inversion, we employ the double-difference travel time misfit functional to maximize the retrieval of structural information using only the highest quality shot gathers and a limited number of simulations. The spatial domain is also limited to stations in the SSIP array as the experiment geometry is well-suited to the proposed scheme. SeisFlows is being used to manage data and kernel processing, simulations performed through SPECFEM3D, and model optimization to ensure reproducibility and ease of experimentation with a different workflow by other researchers. Our starting model is a hybrid model produced in previous work that is comprised of 3D local SSIP travel time models embedded into CVM-H 15.1. We are working in a 1-4 Hz frequency band and using only vertical component seismograms for the first step in our multiscale updates.

Key Words
Full waveform inversion, community models

Ajala, R., Persaud, P., & Juarez, A. (2021, 08). Beyond 1 Hz: Double-difference active source adjoint tomography of Salton Trough. Poster Presentation at 2021 SCEC Annual Meeting.

Related Projects & Working Groups
SCEC Community Models (CXM)