HIGH-ORDER FINITE DIFFERENCE MODELING OF RAYLEIGH WAVE IN TWO-DIMENSIONAL ELASTIC MEDIA

In order to study the generation mechanism and propagation rule of Rayleigh waves in complex media,and to understand the collected results correctly and improve the inversion precision,it was used the 410 high-order finite difference method with staggered grids to simulate full-wave-fields in elastic media.Synthetic single-shot records and snaps of a homogeneous half-space,a layered media in which shear wave velocity increasing with depth and a layered media with a low velocity interlayer were got by the above simulation.According to the results of model simulation,the past low-order finite difference method is not suitable to study the dispersion characteristics of Rayleigh waves because it may cause serious numerical dispersion.The high-order finite difference method with staggered grids can suppress numerical dispersion effectively,and its modeling results of layered media are consistent with calculation results of dispersion equation.Therefore,this method can be used to study complex non-layered media,and to discuss their dispersion characteristics and instruct practical prospecting works.