Accession Number : ADA296051

Title :   Relationships between Ocean Bottom Noise and the Environment.

Descriptive Note : Final rept. 1 Oct 89-30 May 95,

Corporate Author : SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA

Personal Author(s) : Babcock, Jeffrey M. ; Kirkendall, Barry A. ; Orcutt, John A.

PDF Url : ADA296051

Report Date : 27 JUN 1995

Pagination or Media Count : 39

Abstract : Observations of ocean bottom low frequency noise and surface environmental data over a period of 27 days in the North Atlantic during the SAMSON and SWAE experiments reveal how closely related the noise is to meteorological conditions. Double frequency microseisms produced by nonlinear interactions of storm-induced surface gravity waves are especially evident in the frequency band O.16-0.3 Hz and show a high variability in both amplitude and peak frequencies. Bifurcated at times, the peak which characterizes the microseism band contains local and distant or teleseismic components which are generated at different locations. Weather and storm fetch appear to be the major contributors to the size and shape of microseism spectra. Storm development on the sea surface is associated with progressively lower microseism frequencies along with a concurrent increase in amplitude. The single frequency microseism peak is a continuous feature and is observed to portray the same time-dependent spectral characteristics as the portion of the double frequency peak associated with distant storms. Coherence studies confirm that both peaks (single and teleseismic double) originate at a distant source. These peaks are generated at roughly the same location with some storm component over the coastline. (AN)

Descriptors :   *AMBIENT NOISE, *NORTH ATLANTIC OCEAN, *OCEAN BOTTOM, *MICROSEISMS, PEAK VALUES, OCEAN WAVES, OCEAN SURFACE, TIME DEPENDENCE, COHERENCE, OCEANOGRAPHIC DATA, BATHYMETRY, SEISMIC DATA, FREQUENCY BANDS, NONLINEAR SYSTEMS, SEASONAL VARIATIONS, LONG RANGE(DISTANCE), STORMS, SEISMIC WAVES, WIND VELOCITY, AIR WATER INTERACTIONS, MARINE METEOROLOGY, OCEAN ENVIRONMENTS, SEISMOGRAPHS.

Subject Categories : Physical and Dynamic Oceanography
      Seismology

Distribution Statement : APPROVED FOR PUBLIC RELEASE