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Sensitivity Analysis of Rayleigh-wave Ellipticity with Application to Near Surface Characterization
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics, Sep 2015, Volume 2015, p.1 - 5
Abstract
The joint inversion of surface-wave measurements and Rayleigh-wave ellipticity has gained popularity in recent years for near-surface soil characterization. The common approach is to use low-frequency, single-station ellipticity data in conjunction with high-frequency dispersion measurements obtained employing small aperture arrays. A complete understanding of the diagnostic potential of ellipticity in such conditions can be assessed only with a complete sensitivity analysis.
To this end, a new analytical method is presented for computing the sensitivity of Rayleigh-wave ellipticity with respect to the structural parameters of a layered elastic halfspace. This method employs a layer stacking procedure based on the subdeterminant formulation of the surface-wave forward problem and is numerically stable at high frequencies.
The sensitivity of the ellipticity curve is then evaluated quantitatively with specific focus on near-surface examples and compared to the dispersion patterns and sensitivity of modal phase velocity.