Love wave along the corrugated interface between an elastic half-space and the corrugated porous layer containing two fluids

Abstract

This article presents a comprehensive analysis of Love wave propagation along the interface between a porous layer saturated with two immiscible fluids and an underlying elastic half-space. The study places particular emphasis on the corrugated nature of both the interface and the upper boundary of the porous layer. A complex dispersion relation, governed by appropriate boundary conditions, is derived and subsequently simplified into four distinct subcases. The effects of corrugation parameters at the upper boundary of the porous layer and the interface between the layer and the elastic half-space are investigated. The influence of the undulation parameter, which represents the combined effects of wave number and porous layer thickness is also analyzed on the phase speed of the Love wave. In the numerical discussion, a geological structure analogous to oil-contaminated sandstone aquifers in contact with sedimentary bedrock, a common formation in coastal regions, is considered as a realistic example. The key findings reveal that the phase speed of Love waves is highly sensitive to both the corrugation and undulation parameters. Increased corrugation at the upper boundary of the layer enhances phase speed, while corrugation at the interface decreases it. An increase in the undulation parameter decreases the phase speed of the Love wave. Additionally, the presence of oil and water within the porous sandstone significantly reduces phase speed, particularly at lower frequencies, due to higher viscosity and internal friction. This study provides valuable insights into wave propagation dynamics in complex geological settings, with implications for hydrogeology, environmental monitoring, and seismic risk assessment.