Two-dimensional seismic wave simulation in anisotropic media by non-staggered finite difference method
二维各向异性介质中地震波场的高阶同位网格有限差分模拟

In this paper, a DRP/opt MacCormack finite difference scheme is used to simulate seismic wave propagation in two-dimensional anisotropic media. DRP/opt MacCormack is a non-staggered finite difference scheme which avoids the stress/strain interpolation in traditional staggered finite difference method. Compared to low-order non-staggered finite different scheme, it has low dispersion and dissipation. This scheme divides center difference to forward and backward one-side difference operators which are combined in 4-6 steps Runge-Kutta time integration. In a transverse isotropic media with vertical axis (VTI), we validate the high accuracy and stability of DRP/opt MacCormack scheme by comparing with spectral element method. In the realistic geological situations, the symmetric axes of transverse isotropic media are tiled (TTI), we simulate three components seismic wavefields in two-dimensional TTI media. The results show shear wave splitting and decoupling of in-plane/anti-plane movements. The numerical simulations show that DRP/opt MacCormack scheme is an efficient tool to study the wavefields in arbitrary anisotropic media. This scheme is suitable for media with arbitrary topographic variations and can be easily implemented in three-dimensional simulations.