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Scattering of plane SV wave by wedge-shaped topographic features
Wedge models have been traditionally used as fundamental elements of topography due to their similarity with features like continental margin, mountain root, and crustal discontinuity. The scattering of seismic waves by elastic wedges has been a topic of interest in seismology and geophysics for many decades. Analytical, semi-analytical, experimental and numerical studies on idealized wedges have repeatedly provided insight into the seismic behavior of these features. Published results, however, have almost exclusively focused on incident Rayleigh waves and out-of-plane body (SH) waves. Complementing the existing body of work, we here present results from our study on the response of elastic wedges to incident SV waves, an idealized problem that can provide valuable insight to the understanding and parameterization of topographic amplification of seismic ground motion. For the numerical part of our analysis, we apply explicit finite differences scheme on a very large finite model to simulate wave propagation in an infinite wedge. The semi-analytical method is based on the generalized reciprocity theorem i.e. the integral solution of wave equation. We apply Laplace transform to reformulate this integral equation in the functional form. We then verify our result by available analytical solutions of infinite wedge. Finally, the verified numerical model is used to perform a systematic analysis of the effects of 2D convex topographic features on the seismic ground motion.Author(s):
Kami Mohammadi
Georgia Institute of Technology
United States
Domniki Asimaki
California Institute of Technology
United States