Crustal reflection of plane<i>P</i>and<i>SV</i>waves

Expressions in terms of layer matrices have been derived for the motion of the free surface when plane harmonic P or SV waves are incident at any given angle at the base of a horizontally layered crust. A computer program has been written to calculate normalized surface displacements as functions of horizontal phase velocity (or angle of incidence) and wave period. Numerical values have been obtained for the same single-layered model of the continental crust for which the corresponding calculations for SH waves have been presented previously. The surface motion pattern is similar to that of the SH case, but it is somewhat more complex owing to PS and SP conversions at the layer boundaries. Variations in amplitude and phase of the surface displacements are particularly large and erratic in the case of SV waves that are incident at angles such that α1 αn, the crustal transfer functions for incident SH and SV waves are sufficiently similar for conventional methods to be used in determining the angle of polarization with moderate accuracy.