The effect of discontinuities in density and shear velocity on the asymptotic overtone structure of torsional eigenfrequencies of the Earth

This paper pursues theoretically and comments on results obtained by Wang, Gettrust & Cleary from a model study of the asymptotic overtone structure of torsional eigenfrequencies of the Earth. It shows that a number of qualitative results, which they derive about the dependence of the asymptotic overtone structure on the position and nature of discontinuities in density and shear velocity, can be derived quantitatively.