Recent advances in more than one dimensional anelastic wave theory predict characteristics of seismic waves in an anelastic Earth that are not predicted by elastic models.

Anelastic solutions of fundamental problems reveal:

1) P and S body waves refracted at anelastic boundaries with wave speeds and attenuation coefficients that vary with contrasts in intrinsic material absorption and angle of incidence,

2) Anelastic seismic rays distinct from those predicted by elastic solutions with measurable differences in ray-path locations, distances, travel times, and amplitude attenuation in the near- surface, crust, and mantle.

3) New insights for interpretation of seismic waves to infer anelastic material characteristics of the Earth's interior.