is both in the direction of propagation and perpendicular (in a vertical
plane), and “phased” so that the motion is
generally elliptical – either prograde or
~ 2.0 - 4.2 km/s in the Earth depending on frequency of the
propagating wave, and therefore the depth of penetration of the waves.
waves are also dispersive and the amplitudes generally decrease with depth
in the Earth. Appearance and particle motion are similar to water
waves. Depth of penetration of the
Rayleigh waves is also dependent on frequency, with lower frequencies
penetrating to greater depth.