Accession Number:

ADA212942

Title:

ULF/VLF (0.001 to 50 Hz) Seismo-Acoustic Noise in the Ocean. Proceedings of a Workshop Held at Austin, Texas on November 29-December 1, 1988

Descriptive Note:

Final rept.

Corporate Author:

RONDOUT ASSOCIATES INC STONE RIDGE NY

Report Date:

1989-08-03

Pagination or Media Count:

201.0

Abstract:

The objective of the research in ULFVLF seismo-acoustic noise in the ocean is to improve our quantitative understanding of the physical processes that generate the acousticseismic ambient noise field in the frequency band from 0.001 to 50 Hz as a function of location and time to experimentally identify and quantitatively define the important noise sources including the discrimination between noise from local and distant sources where possible, to theoretically establish and describe the physical processes which are the noise source in the ULFVLF frequency band and to determine the effects of ocean, bottom, and sub-bottom acousticseismic parameters on the observed noise field, i.e., the effects both of propagation and of local site conditions. General characteristics of important noise sources and of the noise power spectrum are already fairly well established over much of the frequency band of interest most are related to ocean waves and their meteorological sources. Ice motions, earthquakes, volcanic eruptions, turbulent tidal or other water currents, and atmospheric acoustic disturbances also discussed in the Proceedings, are other possible sources that might be considered where appropriate. Propagation through the oceancrustal waveguide between source regions and receiving instrument arrays produces important effects on the observed ambient pressure and the seismic motion components. Relationships among these components depend strongly on the wave type and upon the detailed velocityattenuation structures of the oceanic waveguide in general, the relationships also are strongly frequency dependent.

Subject Categories:

  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE