Accession Number : AD0731362

Title :   Sound Attenuation in the Red Sea.

Descriptive Note : Research rept.,

Corporate Author : NAVAL UNDERWATER SYSTEMS CENTER NEWPORT R I

Personal Author(s) : Jones,Everett N. ; Browning,David G. ; Thorp,William H. ; Mellen,Robert H.

Report Date : 02 AUG 1971

Pagination or Media Count : 45

Abstract : Many experiments have shown that the attenuation of low-frequency (below 10 kHz) sound in sea water is at least 10 times the value predicted by extrapolation from higher frequencies. Since attenuation is a factor in sonar design and propagation prediction, the Naval Underwater Systems Center has initiated a program to determine the exact magnitude, variation, and cause of this anomaly throughout the oceans of the world. This report describes the first experiment, which was conducted in the Red Sea. The results show a shift in relaxation frequency from 1 kHz (Atlantic) to 1.5 kHz (Red Sea). The corresponding activation energy is 3.1 kcal/mole. Results support the contention that a chemical relaxation causes the anomaly. In practical terms, this experiment shows that the Thorp formula gives a good estimation for attenuation anywhere in the oceans and can be made more exact by correcting for temperature. (Author)

Descriptors :   (*UNDERWATER SOUND, *RED SEA), LOW FREQUENCY, ATTENUATION, SALINITY, TEMPERATURE, SEA WATER, CORRECTIONS, ANOMALIES

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

Distribution Statement : APPROVED FOR PUBLIC RELEASE