Application of the extended poroacoustic model of marine sediments to the calculation of the sound reflection coefficient from the seabed

Abstract

The article consider the application of the extended poroacoustic theory of the propagation of stress waves in marine sediments to the calculation of the coefficient of sound reflection from the seabed. It is proposed to calculate the reflection coefficient using a simple acoustic formula, replacing the equilibrium density of the porous medium in it with the effective density. The main assumptions are given and the dispersion relations of the extended poroacoustic model of unconsolidated marine sediments are derived (GSED). Model GSED allows calculating the frequency dependences of the propagation velocity and the attenuation coefficients of sound and shear waves in marine sediments. Internal friction between granules and viscous losses due to relative fluid movement are taken into account. The adequacy of GSED model is shown by comparison with experimental data taken from open sources. The results of calculating the reflection coefficient within the framework of the proposed method are compared with experimental data.