Rayleigh Waves in Anisotropic Media

It is shown that, in general, Rayleigh waves in semi-infinite anisotropic media are either (i) dissipative, or (ii) not propagated at all. It is possible that non-dissipative Rayleigh waves can travel in certain discrete directions. These directions are probably the borders between the wedges in which the Rayleigh waves are dissipative and the wedges in which they do not exist. If the free plane surface, however, is a plane of symmetry of the anisotropic material, Rayleigh waves, if they exist, are neither dissipative nor dispersive. The geometry of their propagation and the decay of their amplitudes is discussed in terms of the slowness and wave curves.