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Multi-channel analysis of surface waves MASW of models with high shear-wave velocity contrast

J. Ivanov·R. D. Miller·S. Peterie·C. Zeng·J. Xia·T. Schwenk
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Abstract

We use the multi-channel analysis of surface waves MASW method to analyze synthetic seismic data calculated using models with high shear-wave velocity Vs contrast. The MASW dispersion-curve images of the Rayleigh wave are obtained using various sets of source-offset and spread-size configurations from the synthetic seismic data and compared with the theoretically calculated fundamental- and higher-mode dispersion-curves. Such tests showed that most of the dispersion-curve images are dominated by higher-mode energy at the low frequencies, especially when analyzing data from long receiver offsets and thus significantly divert from numerically expected dispersion-curve trends, which can lead to significant Vs overestimation. Further analysis showed that using data with relatively short spread lengths and source offsets can image the desired fundamental-mode of the Rayleigh wave that matches the numerically expected dispersion-curve pattern. As a result, it was concluded that it might be possible to avoid higher-mode contamination at low frequencies at sites with high Vs contrast by appropriate selection of spread size and seismic source offset. ?? 2011 Society of Exploration Geophysicists.

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J. Ivanov, R. D. Miller, S. Peterie, C. Zeng, J. Xia, T. Schwenk. 2011-08-08. Multi-channel analysis of surface waves MASW of models with high shear-wave velocity contrast. https://doi.org/10.1190/1.3627461

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