Zoeppritz equations

Summary

The Zoeppritz equations give the amplitudes of the reflected and transmitted waves when a plane elastic wave hits a flat interface between two solids. An incident P-wave in general produces four waves: a reflected P-wave, a reflected S-wave, a transmitted P-wave and a transmitted S-wave. The equations are a $4 \times 4$ linear system expressing that displacement and traction are continuous across the interface. They are the exact basis of amplitude versus offset analysis in exploration seismology.