Earth model-space exploration in Southern California: Influence of topography, geotechnical layer, and attenuation on wavefield accuracy

Accurately predicting the seismic wavefield is important for physics-based earthquake hazard studies and dependent on an accurate source model, a good model of subsurface geology, full physics wave propagation. Here, we conduct numerical experiments to investigate effect different representations Southern California Earthquake Center Harvard community velocity models waveform predictions in vicinity San Andreas fault Salton Trough. We test general preconceptions about importance topography, near-surface geotechnical layering, anelastic attenuation up maximum frequency 0.5 Hz. For developed without implement 1D linear extensions that preserve geologic structure pull-up approach adapts original topographic variations distorts subsurface. The includes elevation so squashed topography representation, which flattens it. both models, modify top 350 m by partially applying Ely layer using minimum shear 600 m/s incorporate Olsen ratio 0.05. evaluate resulting 24 classical misfit five moderate-magnitude earthquakes. Only inclusion consistently improves predictions. It becomes more impactful at higher frequencies, where it significantly performance levels crude extension close version. representation also enhances prediction ability model. Squashing elevation-referenced produces better seismogram fits, suggesting imagers construct tomographic avoid issues related missing parameters near free surface or discrepancies with Although implementation would permit velocities as low 90 proves computationally expensive, our partial provides slightly results some cases. Our can serve recommendations implementing these future validation optimization studies.