A Review of Low-Frequency Sound Attenuation in the Ocean.
Abstract
The trend to lower sonar frequencies following WW 2 has revealed the existence of two and possibly more regimes of excess attenuation of sound in the oceans. The first of these, identified as a relaxation absorption caused by the MgSO4 content in sea water and, below 100 kHz, results in an increase in the absorption coefficient over fresh water by roughly a factor of 20. The second shows a further increase by a factor of 10 below 1 kHz. A number of hypotheses, including a second relaxation, have been proposed to explain the excess attenuation anomaly. Experimental techniques, data analysis, and mathematical models are discussed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 18, 1971
- Accession Number
- AD0782274
Entities
People
- D. G. Browning
- E. N. Jones
- R. H. Mellen
- W. H. Thorp
Organizations
- Naval Undersea Warfare Center