Earthquake Ground Motions in Community and Hybrid Earth Models in Salton Trough: Coupling Influence of Topography, Geotechnical Layering, and Anelasticity

Rasheed Ajala, Patricia Persaud, & Alan Juarez

In Preparation March 13, 2021, SCEC Contribution #10950

Accurately predicting the full seismic wavefield in the Earth depends on accounting for the complete physics of wave propagation, an accurate source model, and having the best model of the Earth’s geologic structure. We evaluate two popular community models in Salton Trough in terms of ground motion estimates by validating a few representations of the models that include topography, attenuating rheology, and a geotechnical layer or the lack thereof. For one of the models developed without topography, we test a 1D and linear extension of the model parameters to the real free surface and a default representation that morphs the original model following topographic variations. Hybrid model subspaces for each community model are generated by smoothly embedding high-resolution local models using a Tukey window with arbitrary support and varying taper degrees. Only the inclusion of attenuation consistently produces better predictions. We show other factors to be coupled or model-inherent.

Citation
Ajala, R., Persaud, P., & Juarez, A. (2021). Earthquake Ground Motions in Community and Hybrid Earth Models in Salton Trough: Coupling Influence of Topography, Geotechnical Layering, and Anelasticity. Geophysical Research Letters, (in preparation).


Related Projects & Working Groups
Assimilating SSIP data into a Full 3D Tomography (F3DT) model of the Salton Trough, SCEC Community Models (CXM), Ground Motions (GM), San Andreas Fault System (SAFS)