The contribution of topographic scattering to teleseismic coda in southern California

Given that seismic coda is largely the result of scattering near the receiver, a tie to geological complexity, i.e., to crustal heterogeneity, is expected, but a systematic and predictive understanding of the important aspects of geology is lacking. We have developed a technique for mapping the origins of coda energy as recorded by regional networks that provides insight into the proximal generation of seismic coda. Here, the role of topography in the production of surface‐propagating coda energy, both as a scatterer and as a proxy of shallow geologic structure, is examined for the portion of the San Andreas fault system within the Southern California Seismic Network. We find significant correlation of P to Rg scattering potential with topographic roughness that extends to relatively subtle topography. The correlation peaks at a migration velocity of ∼2.9 km/s, confirming the identification of scattered Rg energy and offering an alternative means of estimating regional shallow velocity structure.