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地震横波分裂参数是确定地球介质各向异性基本特征的重要依据.在过去几十年间,快横波偏振方向和快-慢横波到时差测量值的显著离散已经成为影响学界对地震各向异性和横波分裂进行深入研究的一个突出障碍.本文具体分析了实际地球介质的各向异性和非均匀性可能引起的地震记录上地震波震相观测走时和理论走时的偏离、观测偏振和理论偏振的偏离,以及震相观测序列和理论序列的偏离;指出了实际三分量地震记录上地震波震相矢量普遍存在的偏振非正交和路径非正交关系是传统正交分离和参数测量结果显著离散的根本原因;用仿真模拟实例分析了现有震相识别和波形分析方法可能带来的震相漏识别或误识别,介绍了利用矢量分析技术分离三分量观测记录上地震波震相完整波形的基本思路,推导了以地震波空间偏振矢量方向为参数的波形分离运算表达式,以及直接利用三分量地震记录的傅里叶频谱在不同坐标分量上的投影来测量地震记录上各个震相矢量空间方向的近似方法.
Seismic shear-wave splitting parameters are an important basis for determining the fundamental characteristics of the anisotropy of the Earth’s medium.In the past few decades, the significant dispersion of the fast-shear-wave polarization direction and the fast-slow shear-wave to time-lapse measurements have become critical factors affecting the seismic anisotropy and shear wave A major obstacle to in-depth study of the splitting.In this paper, we analyze in detail the deviations of observed time and theoretical travel time, the deviations of observed and theoretical polarizations that may be caused by the seismic wave seismic phases on the seismic records caused by anisotropy and inhomogeneity of the real earth medium It is pointed out that the non-orthogonal polarizations and non-orthogonal paths of seismic phase phasors in actual three-component seismic records are the fundamental reasons for the traditional orthogonal separation and the significant discrepancy of the measured parameters. A simulation example is given to analyze the possible phase-out recognition or misrecognition of the existing phase identification and waveform analysis methods. The basic idea of separating the complete waveform of the seismic phase from the three-component observation records by using vector analysis is introduced. Separation of Waveform Expression with Parameter of Space Polar Vector Direction of Seismic Wave , And the direct use of three-component seismic recording the Fourier spectrum of the different components of the coordinate measuring projection direction vector space approximation respective phases on the seismic record.