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