Abstract
The vertical distribution of amplitudes is studied for the M11 type dispersive Rayleigh wave which is propagated along the surface of a superficial layer overlying a semi-infinite elastic medium.
Among others, the case in which the velocity of the distortional wave in the substratum is lower than that in the superficial layer, that is to say, the case that the substratum is a low velocity layer, is especially investigated.
The results obtained are as follow.
(1) The amplitude distribution and the particle orbits of the M11 waves are analogous to those of the nondispersive Rayleigh wave which is propagated along the surface of a semi-infinite elastic solid. This is true even if the substratum is a low velocity layer.
(2) If the substratum is rigid, the particle orbit for the waves of which the wave lengths are longer than about 4.6H (H: thickness of the superficial layer), is of an opposit sense in contrast with that for other waves in the existence domain.
