Group-velocity dispersion analysis of high-frequency rayleigh waves
Most MASW researchers mainly apply Rayleigh-wave phase-velocity dispersion for S-wave velocity estimation with a few exceptions applying Rayleigh-wave group-velocity dispersion. Herein, we first compare sensitivities of fundamental surface-wave phase velocities with group velocities with three four-layer models including a low-velocity layer or a high-velocity layer. Then synthetic data are simulated by a finite difference method. Images of group-velocity dispersive energy of the synthetic data are generated using the Multiple Filter Analysis (MFA) method. Results demonstrate that (1) the sensitivities of group velocities are higher than those of phase velocities and usable frequency ranges are wider than that of phase velocities, which is very helpful in improving inversion stability because for a stable inversion system, small changes in phase velocities do not result in a large fluctuation in inverted S-wave velocities; (2) group-velocity dispersive energy can be imaged using single-trace data if Rayleigh-wave fundamental-mode energy is dominant, which suggests that the number of shots required in data acquisition can be dramatically reduced and the horizontal resolution can be greatly improved using analysis of group-velocity dispersion.
Rayleigh waves group velocity dispersion analysis near-surface application
Yinhe Luo Jianghai Xia Yixian Xu Chong Zeng
Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, Hubei 430074, China Kansas Geological Survey, The University of Kansas, USA Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, Hubei 430074,China
国际会议
成都
英文
189-194
2010-06-14（万方平台首次上网日期，不代表论文的发表时间）