Acoustic Characteristics of Subharmonics Generated from Water-Saturated Sandy Sediment

Abstract

Nonlinear acoustic characteristics of sediments are veryimportant to understand nonlinear phenomena of marine gassysediments. Acoustic characteristics of subharmonics generatedfrom water-saturated sandy sediment were investigated. Whena harmonic sound wave with high-amplitude was incident onthe water-saturated sandy sediment, subharmonic componentsof incident wave were generated due to nonlinearity of water-saturatedsandy sediment. The level of generated firstsubharmonic sound wave was about 23 dB greater than thebackground noise level at fundamental frequency withmaximum incident pressure. The level of subharmonic soundwaves was dependent on the amplitude of the harmonics aswell as of the fundamental.