ELASTIC WAVE PROPAGATION IN TRANSVERSELY ISOTROPIC MEDIA USING FINITE DIFFERENCES¹

Abstract

A bstract When treating the forward full waveform case, a fast and accurate algorithm for modelling seismic wave propagation in anisotropic inhomogeneous media is of considerable value in current exploration seismology. Synthetic seismograms were computed for P‐SV wave propagation in transversely isotropic media. Among the various techniques available for seismic modelling, the finite‐difference method possesses both the power and flexibility to model wave propagation accurately in anisotropic inhomogeneous media bounded by irregular interfaces. We have developed a fast high‐order vectorized finite‐difference algorithm adapted for the vector supercomputer. The algorithm is based on the fourth‐order accurate MacCormack‐type splitting scheme. Solving the equivalent first‐order hyperbolic system of equations, instead of the second‐order wave equation, avoids computation of the spatial derivatives of the medium's anisotropic elastic parameters. Examples indicate that anisotropy plays an important role in modelling the kinematic and the dynamic properties of the wave propagation and should be taken into account when necessary.