A wavelet-based method for simulation of two-dimensional elastic wave propagation

A wavelet-based method is introduced for the modelling of elastic wave propagation in 2-D media. The spatial derivative operators in the elastic wave equations are treated through wavelet transforms in a physical domain. The resulting second-order differential equations for time evolution are then solved via a system of first-order differential equations using a displacement-velocity formulation. With the combined aid of a semi-group representation and spatial differentiation using wavelets, a uniform numerical accuracy of spatial differentiation can be maintained across the domain. Absorbing boundary conditions are considered implicitly by including attenuation terms in the governing equations and the traction-free boundary condition at a free surface is implemented by introducing equivalent forces in the semi-group scheme. The method is illustrated by application to SH and P-SV waves for several models and some numerical results are compared with analytical solutions. The wavelet-based method achieves a good numerical simulation and shows an applicability for an elastic-wave study.