Interface scattering by poroelastic seafloors: First-order theory

A perturbation model is developed for sound scattering by a poroelastic seafloor having roughness small compared to the acoustic wavelength. The sediment is assumed to be homogeneous and isotropic with wave propagation described by Biot’s equations. When applied to sandy sediments, the model predicts backscattering levels that are substantially lower than those of a fluid model having the same roughness, density, sound speed, and attenuation.