The Effect of Ice Cover on Shallow Water Ambient Noise

Abstract

Ambient sea noise in the frequency range 12.5–6400 Hz was measured in the Cabot Strait, near Cape North, Nova Scotia, during the period 23 February to 16 April 1971 with a bottom-mounted hydrophone at a 350 ft depth. During this period, floe ice moved continuously, giving ice coverage that varied from 0/10ths to 10/10ths. The wind-dependent noise spectra and distributions of spectral levels are presented for various degrees of ice coverage. It was found that the spectral levels are wind dependent for all degrees of ice cover, but the under-ice spectral levels are significantly lower than the open water levels for comparable wind velocities.