Nonlinear Properties of In-Situ Sediment Gas Bubbles

摘要

A model for difference frequency backscatter from trapped bubbles in sandysediments is developed. The Biot theory is incorporated to model the acoustics of sandy sediment. Biot fast and slow waves are included by modeling the pore fluid as a superposition of two acoustic fluids with effective densities that differ from the pore fluid's actual density and account for its confinement within sediment pores. The principle of acoustic reciprocity is employed to develop an expression for the backscattering strength.