SCATTERING OF ELASTIC-WAVES BY A SPHERICAL INCLUSION .1. THEORY AND NUMERICAL RESULTS

A complete and exact solution for the problem of an incident P wave sc attered by an elastic spherical inclusion is presented and described. The solution can be obtained from either analytical formulae or stable numerical procedures. A method of estimating the number of terms that must be retained in the harmonic series in order to achieve a specifi ed accuracy is given. The results are investigated by calculating synt hetic seismograms, scattering diagrams, and scattering cross-sections for a broad frequency band and for both low-velocity and high-velocity inclusions. The fields within the shadow zone are formed primarily fr om three different types of waves, P waves transmitted through the sph ere, P waves diffracted around the sphere, and S waves converted at th e boundary of the sphere. The relative contribution from these differe nt waves depends upon the distance of the observation point from the s phere.