Torsional waves in a magneto-viscoelastic layer over an inhomogeneous substratum

Abstract

The propagation of torsional waves generated during earthquakes or mechanical explosions encounter various anomalies like layered structure, crustal inhomogeneities, geomagnetic field, viscosity etc. These anomalies significantly change the governing characteristics of propagating seismic waves. In the present study the authors explored the torsional-surface-wave propagation in a homogeneous magneto-viscoelastic layer over an inhomogeneous magneto-isotropic substratum. A closed-form solution for displacements in layer and substratum is found and the generalized absorption-dispersion relation is derived analytically. The characteristics of torsional waves in some simpler geometry have been deduced as particular cases to the present study. The impact of inhomogeneities-free lower substratum and the absence of magnetic field from layer and substratum is further investigated using numerical simulations and results were analyzed using implicit contour plotting.