A note on the earth-stretching approximation for Love waves

Earth-flattening transformations provide an efficient means for computing Love-wave dispersion and torsional normal mode frequencies in radially heterogeneous, spherically symmetric earth models. These transformations involve simple algebraic sealing factors applied to solutions for SH waves in a layered half-space. They result in considerable computational savings over solutions expressed directly in spherical geometry. Several earth-flattening transformations for SH waves are described in the literature (Anderson and Toksöz, 1973; Sato, 1968; Biswas and Knopoff, 1970). Chapman (1973) has examined the general class of power-law earth-flattening transformations and their application to body-wave problems.