Rayleigh‐wave dispersion analysis using complex‐vector seismic data

Abstract

A B S T R A C TIdentification of different modes of Rayleigh waves is essential in surface-wave surveys. Multi-mode Rayleigh waves can provide higher accuracy of the near-surface structure than the fundamental mode alone. However, some modes or frequencies of Rayleigh waves may be absent in the vertical-component seismic data. To complement the dispersion information, a method based on complex-vector seismic data is proposed. We construct the complex vector by setting the radial component and vertical component as the real part and imaginary part, respectively. Then, high-resolution linear Radon transform is used to obtain the multi-mode Rayleighwave dispersion image of the complex-vector seismic data. Based on different dispersion characteristics of the radial and vertical components, the dispersion images of the complex-vector seismic data show better performance against interferences and mode misidentification. Synthetic and field examples demonstrate advantages of the complex-vector method over the traditional vertical-component method in spectral bands and dispersion curve mode identification. Therefore, a more robust and accurate near-surface S-wave velocity structure can be expected compared to the traditional vertical-component Rayleigh-wave method.

Multiple Leaking Mode Dispersion Observations and Applications From Ambient Noise Cross‐Correlation in Oklahoma

“…We consider that N1 may be missing from the dispersion extraction in this study. It is worth noting that the determination of the number of dispersion curves is still an important issue that needs to be further studied in overtone dispersion inversion (Qiu et al., 2019; Zhang & Chan, 2003). This consideration in this study is mainly based on the local reference model and the inversion using only N0 and G1.…”

Tunnel Concealed Karst Cave Joint Detection by Tunnel Seismic and Transient Electromagnetic

“…The lower the offset, the stronger the acoustic wave and the lower the SNR. The distribution of surface waves varies with different components [29]. The surface wave is the most obvious in Y-component (Figures 7(b) and 8(b), B).…”

Rayleigh-Wave Dispersion Analysis and Inversion Based on the Rotation

“…The dispersive energy in the f–v domain can be imaged with the module of the Radon coefficients [ 14 ]. Then, the imaged energy is normalized at each frequency, which can remove the effect of the source wavelet spectrum [ 26 ].…”

“…However, the effective identification and accurate extraction of different modes and overcoming the difficulty of misidentification of Rayleigh-wave modes caused by the phenomenon of “mode kissing” has become the main problem faced by the traditional SPAC (spatial autocorrelation) method [ 22 , 23 , 24 ]. The high-resolution linear Radon transform [ 25 ] and the complex vector method, which jointly use the multi-component seismic data, show good results in extracting the surface-wave dispersion curves of different modes [ 26 ]. The joint use of the radial and vertical components of seismic translational motions to invert the shallow velocity structure has also been widely used [ 27 , 28 , 29 , 30 , 31 ].…”