The generation of infrasonic ambient noise in the ocean by nonlinear interactions of ocean surface waves

Abstract

Expressions for the spectra of infrasonic ocean noise and microseisms induced by nonlinear wave interaction are derived theoretically for an ocean environment modeled as a water layer overlying a solid half-space. A series of spectral transfer functions relating the source pressure field induced by the wave action to the underwater acoustic noise field and that of the microseisms this generates in the seabed are defined and calculated. The effect of bottom reflections on the transfer function is examined and an estimate of the contribution of the Rayleigh wave component of the microseism signal received onshore is also made.