An S-wave is a wave in an elastic medium in which the restoring force is provided by shear. S-waves are divergenceless,
where u is the displacement of the wave, and come in two polarizations: SV (vertical) or SH (horizontal). The speed of an S-wave is given by
where is the shear modulus and is the density.
Elastic Wave, P-Wave, Seismic Parameter, Shear
