Summary of a One-Year Ambient Noise Measurement Program Off Bermuda

Abstract

Abstract : The results of ambient noise data recorded simultaneously during a one year period between January and December 1966 from 5 hydrophones located in the Northwest Atlantic at depths of 30, 400, 1100, 2400, and 2500 fm (55, 730, 2000, 4400, and 4500 m) are presented. The results show a dependence in the ambient noise spectrum levels as a function of depth, frequency, and wind speed. The shallow hydrophone (at 30 fm or 55 m) was more wind dependent than the deeper ones, especially at frequencies below 281 Hz. Above 281 Hz, the correlation coefficient of the ambient noise spectrum levels with wind speed is observed to be essentially independent of water depth for all 5 hydrophones. No significant seasonal effects on the mean values of the ambient noise levels is observed as a function of depth, except for differences in level caused by the wind speed conditions existing during the different seasons. The difference in ambient noise level between hydrophone depths as a function of frequency is suspected to be the result of the two major directional noise sources existing in deep ocean areas.