Electroseismic Scholte‐wave analysis: A potential method for estimating shear‐wave velocity structure of shallow‐water seabed sediments

Abstract

The potential application of conducting Scholte‐wave analysis using electroseismic (ES) pressure fields excited by an electric current source due to the electrokinetic effect in fluid‐saturated porous seabed sediments is investigated. Firstly, we develop a numerical modeling algorithm by combining the Luco‐Apsel‐Chen generalized reflection and transmission method with the peak‐trough averaging method to simulate the ES wave fields in stratified fluid/porous media. The modeling results show that the ES pressure signals recorded on the seafloor are mainly composed of evanescent ES waves, and Scholte waves are the dominant wave pattern. Their amplitudes are generally within the order of magnitudes capable of being detected by current seismic instruments. Then, the modified frequency‐Bessel transform method is extended to extract the Scholte‐wave dispersion curves from ES pressure fields. Results demonstrate that Scholte‐wave dispersion curves extracted from ES records are superior to those extracted from conventional seismic wave fields excited by an air‐gun source under the same source‐receiver geometry because they contain many overtones and are almost free from the interferences of dispersive guided waves. Furthermore, the Scholte‐wave dispersion inversion results obtained by employing the Levenberg‐Marquardt method show that the shear‐wave velocity model inverted by Scholte‐wave dispersion curves extracted from the ES pressure field is more accurate than those obtained by dispersion curves extracted from the seismic wave fields with the guided‐wave removal. The above results indicate that the ES Scholte‐wave analysis method has the potential to evaluate the shear‐wave velocities of shallow‐water seabed sediments.This article is protected by copyright. All rights reserved