The Motions of the Free Surface due to Plane Body Waves and S-Wave Polarization Angles

Abstract

The displacement and energy of seimic body waves at the free surface of the ground due to plane P, SV and SH waves incident at the bottom of the crust are calculated by Haskell's method for a four-layered crustal model in the western Japan. For same crustal model, the particle motions due to the incident P and SV waves are also discussed on the basis of displacements and phase differences.
Charts of F_h and F_v in equation (5) for determining the polarization angle of S waves are given for three cases of crustal model: two-layered model in the western, central and eastern Japan. These are usefull for the investigation of focal mechanism by the use of S wave data at short epicentral distances.