A fourth-order accurate finite-difference scheme for the computation of elastic waves

Abstract

A finite-difference model for elastic waves is introduced. The model is based on the first-order system of equations for the velocities and stresses. The differencing is fourth-order accurate on the spatial derivatives and second-order accurate in time. The model is tested on a series of examples including the Lamb problem, scattering from a plane interfaces and scattering from a fluid-elastic interface. The scheme is shown to be effective for these problems. The accuracy and stability is insensitive to the Poisson ratio. For the class of problems considered here, we find that the fourth-order scheme requires from two-thirds to one-half the resolution of a typical second-order scheme to give comparable accuracy.