In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 101, No. 5_Supplement ( 1997-05-01), p. 3031-3031
Abstract:
During a recent seismoacoustics experiment, a moored, near-bottom, source just outside the surf zone (approximately 500-m seaward) in 9-m deep water, transmitted 8 tones from 70 to 700 Hz. Recordings were made by several fixed sensor systems, including: 1) a bottom hydrophone/3-component geophone package 15-m distant; 2) two horizontal bottom hydrophone arrays in a nearly perpendicular configuration in 12-m water 1.23 km away and 1.06 km farther offshore; and 3) five 3-component geophones buried at approximate 14-m spacing across the beach at 480–530 m range. These data were used to create 5-min time series of the spectral levels and directionality of the tones every 1/2 h over an 8-h period. Results indicate that within a 5-min period, fluctuations of 10–15 dB occur in the bottom hydrophone array signal levels which, typically, are not correlated from frequency to frequency. Fluctuations in the land geophone data are somewhat smaller, and only the 2 or 3 highest-frequency tones are detectable. Variations in water depth, measured by a package also located just outside the surf zone, are used with an adiabatic normal mode model to predict the fluctuation effects of ocean surface wave activity alone. [Work supported by ONR, Code 32].
Type of Medium:
Online Resource
ISSN:
0001-4966
,
1520-8524
Language:
English
Publisher:
Acoustical Society of America (ASA)
Publication Date:
1997
detail.hit.zdb_id:
1461063-2
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