Sound Attenuation in the Red Sea.

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)

Document Details

Document Type
Technical Report
Publication Date
Aug 02, 1971
Accession Number
AD0731362

Entities

People

  • David G. Browning
  • Everett N. Jones
  • Robert H. Mellen
  • William H. Thorp

Organizations

  • Naval Undersea Warfare Center

Tags

DTIC Thesaurus Topics

  • Attenuation
  • Energy
  • Extrapolation
  • Frequency
  • Heat Of Activation
  • Oceans
  • Red Sea
  • Sea Water
  • Water

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Oceanography.
  • Systems Analysis and Design