A review of numerical experiments on seismic wave scattering

摘要: This paper reviews applications of the finite-difference and finite-element methods to study seismic wave scattering in both simple complex velocity models. These numerical simulations have improved our understanding portions earth where there is significant lateral heterogeneity, such as crust. The propagate complete wavefields through highly media include multiply scattered waves converted phases (e.g.,P toSV, SV toP, body surface wave). been especially useful cases moderate strong multiple becomes important. Progress has made with how near-surface, low-velocity basin structures scatter vertically-incident waves. proven evaluating from topography free interfaces buried at depth. Numerical studies demonstrated importance conversions (andvice versa) when heterogeneities topographic relief are present uppermost Recently, several investigations applied propagation models which vary randomly space. stochastic approach seeks understand effects small-scale complexity cannot be resolved deterministically. experiments quantified relationships between statistical properties random heterogeneity measurable high-frequency (≥1 Hz) seismograms. many features observed actual waves, including: amplitude time decay coda, apparent attenuation scattering, dispersion waveforms, travel waveform variations across arrays receivers.