Torsional Wave Propagation in an Initially Stressed Anisotropic Heterogeneous Crustal Layer Lying Over a Viscoelastic Half-space

Abstract

The present paper is concerned with the study of propagation of torsional surface waves in a non-homogeneous crustal layer under initial stress overlying a viscoelastic half-space. In the layer directional rigidities and density are considered to vary quadratically with depth. The dispersion equation is derived in closed form by means of separation of variables. As a special case when the layer is homogeneous, the dispersion relation coincides with the classical torsional wave equation. To show the nature of torsional waves, dispersion curves have been plotted by taking variation in initial stress, inhomogeneity and viscoelastic parameters. The substantial influence of initial stress, heterogeneity and viscoelastic parameter on the phase velocity are elucidated by means of graphs. This problem may find its applications in the field of earthquake engineering and geophysical prospects.