Ambient noise analysis and finite difference modelling of VLF borehole seismic data
Stephen, Ralph A.
Swift, Stephen A.
Bolmer, S. Thompson
MetadataShow full item record
This report describes a preliminary analysis of borehole seismic data to determine VLF/Sub-bottom Seismic Noise in the Atlantic and the preliminary results of finite difference modelling for a Cape Fear environment. Noise levels were not a simple function of depth and there are indications that noise levels may depend on local geology about a given receiver position and/or on clamping. Coherency of the noise was generally poor (<0.8) and was independent of depth. There is no evidence for distinct polarizations or directionality of the noise. The lowest determined value for ambient noise power on the vertical component was 10-4 nm2/Hz in the frequency range from 5-50 Hz. The better clamped horizontal component had comparable power values. In conclusion, although the drill ship was on the site and drill pipe was in the hole, analysis of the data for a large number of windows can provide meaningful upper bounds on the ambient noise levels in the upper crust.
Suggested CitationWorking Paper: Stephen, Ralph A., Swift, Stephen A., Bolmer, S. Thompson, "Ambient noise analysis and finite difference modelling of VLF borehole seismic data", 1987-03, DOI:10.1575/1912/2640, https://hdl.handle.net/1912/2640
Showing items related by title, author, creator and subject.
Ice shelf structure derived from dispersion curve analysis of ambient seismic noise, Ross Ice Shelf, Antarctica Diez, Anja; Bromirski, Peter D.; Gerstoft, Peter; Stephen, Ralph A.; Anthony, Robert E.; Aster, Richard C.; Cai, Chen; Nyblade, Andrew; Wiens, Douglas A. (Oxford University Press, 2016-02-16)An L-configured, three-component short period seismic array was deployed on the Ross Ice Shelf, Antarctica during November 2014. Polarization analysis of ambient noise data from these stations shows linearly polarized waves ...
Preliminary examination of the low-frequency ambient noise field in the South China Sea during the 2001 ASIAEX experiment Wei, Ruey-Chang; Chen, Chi-Fang; Newhall, Arthur E.; Lynch, James F.; Duda, Timothy F.; Liu, Chih-Sheng; Lin, Po-Chang (IEEE, 2004-10)This correspondence presents a preliminary examination of the low frequency ambient noise field measured in the South China Sea component of the Asian Seas International Acoustics Experiment (ASIAEX), concentrating on the ...
Wu, Hui-Xia (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1992-06)A six mooring acoustic tomography array was jointly deployed by Scripps Institution of Oceanography and Woods Hole Oceanographic Institution in 1988, and a year long time series of ambient noise in the 200-300 Hz was ...