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Pressure and electric fluctuations on the deep seafloor: Background noise for seismic detection
Author(s) -
Webb Spahr,
Cox Charles S.
Publication year - 1984
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl011i010p00967
Subject(s) - microseism , geology , seafloor spreading , noise (video) , geophysics , quiet , ambient noise level , seismology , electric field , interference (communication) , geodesy , physics , oceanography , sound (geography) , channel (broadcasting) , quantum mechanics , artificial intelligence , computer science , electrical engineering , image (mathematics) , engineering
Pressure and electric field fluctuations are suitable for detecting seismic disturbances on the seafloor in the frequency range of .02 to 2 Hz. The background noise has two maxima in this range. From .01 to .03 Hz the pressure spectrum decreases because hydrodynamic filtering increasingly removes the direct influence of long surface gravity waves. The electric spectrum decreases because of increasing absorption of ionospheric disturbances. From 0.09 to 0.11 Hz both spectra increase sharply to a series of peaks where the non‐linear interference of opposed surface wave trains generates microseisms. At 0.09 Hz the inferred vertical ground motion on the seafloor approaches that of quiet continental sites.