WAVE-PROPAGATION IN A DISSIPATIVE STRATIFIED LAYER

A continuously-stratified solid layer between two homogeneous half-spaces is considered. The dissipative properties are incorporated through a viscoelastic model. Wave phenomena in a layer which are generated by an inhomogeneous wave incident at the boundary are then examined. A detailed analysis of wave propagation is then developed by means of a procedure which decouples the differential equations and the boundary conditions into two simpler subsystems. An appropriate method involving successive approximations provides a simple picture of the wave evolution in the layer. In this context, dissipation is shown to affect the occurrence of turning points. As a numerical application, the field in a porous-rock layer is determined. In addition to causing a decay of the wave amplitudes, dissipation results in involved wave modes.