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Retrieving surface waves from ambient seismic noise using seismic interferometry by multidimensional deconvolution
Author(s) -
Dalen Karel N.,
Mikesell T. Dylan,
Ruigrok Elmer N.,
Wapenaar Kees
Publication year - 2015
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2014jb011262
Subject(s) - deconvolution , seismic interferometry , ambient noise level , rayleigh wave , noise (video) , geology , acoustics , seismic noise , cross correlation , seismology , signal (programming language) , microseism , passive seismic , surface wave , physics , optics , computer science , interferometry , mathematics , statistics , artificial intelligence , image (mathematics) , programming language , sound (geography)
Retrieving virtual source surface waves from ambient seismic noise by cross correlation assumes, among others, that the noise field is equipartitioned and the medium is lossless. Violation of these assumptions reduces the accuracy of the retrieved waves. A point‐spread function computed from the same ambient noise quantifies the associated virtual source's spatial and temporal smearing. Multidimensional deconvolution (MDD) of the retrieved surface waves by this function has been shown to improve the virtual source's focusing and the accuracy of the retrieved waves using synthetic data. We tested MDD on data recorded during the Batholiths experiment, a passive deployment of broadband seismic sensors in British Columbia, Canada. The array consisted of two approximately linear station lines. Using 4 months of recordings, we retrieved fundamental‐mode Rayleigh waves (0.05–0.27 Hz). We only used noise time windows dominated by waves that traverse the northern line before reaching the southern (2.5% of all data). Compared to the conventional cross‐correlation result based on this subset, the MDD waveforms are better localized and have significantly higher signal‐to‐noise ratio. Furthermore, MDD corrects the phase, and the spatial deconvolution fills in a spectral ( f , k domain) gap between the single‐frequency and double‐frequency microseism bands. Frequency whitening of the noise also fills the gap in the cross‐correlation result, but the signal‐to‐noise ratio of the MDD result remains higher. Comparison of the extracted phase velocities shows some differences between the methods, also when all data are included in the conventional cross correlation.