Predictions and observations of seafloor infrasonic noise generated by sea surface orbital motion
Lindstrom, Timothy E.
MetadataShow full item record
A model is developed for the prediction of the seismo-acoustic noise spectrum in the microseism peak region (0.1 to 0.7 Hz). The model uses a theory developed by Cato [J. Acoust. Soc. Am., 89 , 1096-1112 (1991)] for an infinite depth ocean in which the surface orbital motion caused by gravity waves may produce acoustic waves at twice the gravity wave frequency. Using directional wave spectra as inputs, acoustic source levels are computed and incorporated into a more realistic environment consisting of a horizontally stratified ocean with an elastic bottom. Noise predictions are made using directional wave spectra obtained from the SWADE surface buoys moored off the coast of Virginia and the SAFARI sound propagation code, with a bottom model derived using wave speeds measured in the EDGE deep seismic reflection survey. The predictions are analyzed for noise level variations with frequency, wave height, wind direction, and receiver depth. These predictions are compared to noise measurements made in ECONOMEX using near-bottom receivers located close to the surface buoys. Good agreement is found between the predictions and observations under a variety of environmental conditions.
Submitted in partial fulfillment of the requirements for the degree of Ocean Engineer at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1991
Showing items related by title, author, creator and subject.
Waldbauer, Jacob R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-02)Biological activity has shaped the surface of the earth in numerous ways, but life’s most pervasive and persistent global impact has been the secular oxidation of the surface environment. Through primary production – the ...
Temporal variability and vertical structure in larval abundance : the potential roles of biological and physical processes Garland, Elizabeth D. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-02)Recruitment variability in benthic invertebrate populations results from variability in planktonic larval supply and from processes occurring during and after larval settlement onto the seafloor. The focus of this thesis ...
Physiological and behavioral diagnostics of nitrogen limitation for the toxic dinoflagellate Alexandrium fundyense Poulton, Nicole J. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-09)One challenge in phytoplankton ecology is to measure species-specific physiological responses to changes in environmental conditions. Of particular importance in this regard are harmful algal bloom (RAB) species such as ...