Modelling Seismic Waves in Strongly Heterogeneous Media Using a Wavelet-Based Method

Tae-Kyung Hong and B.L.N. Kennett (2002)

AGU Fall Meeting, San Francisco, Dec. 6-10, 2002

Most numerical techniques for modelling seismic wave propagation encounter significant difficulties when confronted with media with strong heterogeneity. However, a wavelet-based approach can provide high accuracy and stability of spatial differentiation even in highly perturbed media. The wavelet-based method therefore allows the treatment of localized zones of strong contrast such as media with a fluid-filled crack. The accuracy of the method makes it possible to consider seismic waves in a medium with a weak systematic structure such as subduction zones, where slabs exhibit mild-velocity contrast to the background and therefore there can be significant interface waves on the surfaces of the slabs when the source is close to the slab. The wavelet-based method also allows an accurate treatment of the scattering effect of short-scale heterogeneity, as encountered in the crust. The results indicate that conventional finite difference methods are likely to overestimate scattering attenuation.