Verification of Correctness of Using Real Part of Complex Root as Rayleigh-wave Phase Velocity by Synthetic Models
High-frequency (≥2 Hz) Rayleigh-wave phase velocity have been utilized to determine shear-wave velocities in near-surface geophysics since early 1980s.One of the key steps is to calculate the theoretical dispersion curve of an earth model.When the earth model contains a low-velocity half-space,however,some roots of dispersion equation turn out to be complex numbers,which makes phase velocities disappear at some frequencies.When encountering this situation,we append an additional high velocity layer as the half-space to the model to make the roots real or use the real parts of complex roots as Rayleigh-wave phase velocities.The correctness of the first method has been verified by some scientists;however,the correctness of the second method remains to be unproved.In this paper,we firstly discuss how nearest offset affects a synthetic model and how to choose a suitable nearest offset for a synthetic model.Then we use some synthetic models to verify correctness of using real parts of complex roots as Rayleigh-wave phase velocities when an earth model contains a low velocity layer as the half-space.
Rayleigh wave phase velocity real part of complex root synthetic model
Yudi Pan Jianghai Xia Chong Zeng
Subsurface Imaging and Sensing Laboratory, China University of Geosciences, Wuhan, PRC;Institute of BGP Research and Development Center, Houston, TX, USA
国际会议
长沙
英文
271-275
2012-06-15（万方平台首次上网日期，不代表论文的发表时间）