Accession Number : AD0774884

Title :   Attenuation of Low-Frequency Sound in the Ocean: NUSC Research Program 1967-1972.

Descriptive Note : Technical rept.,

Corporate Author : NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CONN NEW LONDON LAB

Personal Author(s) : Browning,David G. ; Thorp,William H.

Report Date : 04 JAN 1974

Pagination or Media Count : 55

Abstract : During the past five years, the Naval Underwater Systems Center has conducted a series of experiments to study the attenuation of low-frequency sound in sea water. The report reviews each of these investigations and the techniques employed and traces their respective contributions to the current understanding of sound attenuation in the ocean. Experimental evidence suggesting the probable existence in sea water of a relaxational process around one kHz is reinforced by recent laboratory measurements involving boron-borate reactions. Results of measurements in major ocean areas of the world show generally consistent values of low-frequency attenuation, thereby permitting use of simple empirical formulas for adequate prediction at frequencies above 100 Hz. At longer wavelengths, the exact behavior of the coefficients remain poorly defined. (Author)

Descriptors :   *Underwater sound, *Sea water, Attenuation, Low frequency, Sound transmission, Red Sea, Indian Ocean, Hudson Bay

Subject Categories : Physical and Dynamic Oceanography
      Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE