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


Personal Author(s) : Sutton, George H ; Tilley, David G ; Farmer, David ; Holman, R A ; Lewis, B


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a212942.pdf


Report Date : 03 Aug 1989


Pagination or Media Count : 201


Abstract : The objective of the research in ULF/VLF seismo-acoustic noise in the ocean is to improve our quantitative understanding of the physical processes that generate the acoustic/seismic 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 ULF/VLF frequency band; and to determine the effects of ocean, bottom, and sub-bottom acoustic/seismic 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 ocean/crustal waveguide between source region(s) 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 velocity/attenuation structures of the oceanic waveguide; in general, the relationships also are strongly frequency dependent.


Descriptors :   *UNDERWATER SOUND , *SEISMIC WAVES , *AMBIENT NOISE , OCEAN WAVES , OCEAN CURRENTS , PARAMETERS , STRUCTURES , WIND , MOTION , ATMOSPHERIC DISTURBANCES , WAVEGUIDES , POWER SPECTRA , REGIONS , SEISMIC DATA , SPECTRA , ICE , ACOUSTIC ARRAYS , PRESSURE , EARTH CRUST , ATTENUATION , OCEANS , EARTHQUAKES , BOTTOM , CURRENTS , WORKSHOPS , ACOUSTIC FIELDS , ACOUSTIC PROPERTIES , VOLCANOES , SEISMIC ARRAYS , WATER FLOW , LOW FREQUENCIES , VELOCITY , SOURCES


Subject Categories : Acoustics


Distribution Statement : APPROVED FOR PUBLIC RELEASE