Scattering of homogeneous and inhomogeneous viscoelastic waves from arbitrary heterogeneities: update
Shahpoor Moradi, Kristopher A. Innanen
We consider the problem of scattering of homogeneous and inhomogeneous waves from perturbations in five viscoelastic parameters (density, P- and S-wave velocities, and P- and S-wave quality factors), as formulated in the context of the Born approximation. Within this approximation the total wave field is the superposition of an incident plane wave and a scattered wave, the latter being a spherical wave weighted by a function of solid angle called the scattering potential. In elastic media the scattering potential is real, but if dissipation is included through a viscoelastic model, the potential becomes complex and thus impacts the amplitude and phase of the outgoing wave. We show that elliptically polarized P- and SI- waves cannot to leading order be scattered into linearly polarized SIwaves. Furthermore, the elastic formulation is straightforwardly recovered in the limit as P- and S-wave quality factors tend to infinity.