Acoustic penetration of ocean sediments in the context of Biot’s theory.

Abstract

Acoustic penetration of ocean sediments will be examined in the light of the Biot–Stoll theory of sound propagation in porous media. This theory is attractive from a number of perspectives. From an applications point of view, it can account for a number of anomalies that have been observed experimentally but are not explainable in terms of the simpler viscoelastic wave propagation theory. From a theoretical perspective, it provides improved connections between the sediment geophysical properties, such as grain size, porosity, permeability, and frame moduli, and the acoustic properties, such as reflection loss, sound speeds, and attenuations. The difficulty in using Biot’s theory is mostly in the understanding and quantification of certain key input parameters, particularly the elastic moduli of the solid matrix, and of the constituent granular material. The potential reward is a unified theoretical frame work for research into ocean sediment acoustics that brings acoustics and geophysics closer together. ...