APPROXIMATE ANALYTICAL EXPRESSIONS FOR THE VELOCITY OF RAYLEIGH-WAVES IN ISOTROPIC MEDIA AND ON THE BASAL-PLANE IN HIGH-SYMMETRY CRYSTALS

Various approaches to the determination of approximate analytical expressions for the velocity of Rayleigh waves in isotropic media and on the basal plane of rhombic, tetragonal, hexagonal, and cubic crystals are investigated. The Bergmann-Viktorov equation for the Rayleigh wave velocity in isotropic media is generalized to the anisotropic case. The author derives another approximate equation, which is more accurate than the Bergmann-Viktorov equation in the isotropic case.