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根据首都圈地震台网、国家地震台网、IRIS台站资料,并比较了流动的华北地震台阵部分台站资料的结果,利用地震各向异性分析,得到减少局部构造影响后的华北地区(至少是华北地区北部)的地壳背景水平主压应力方向为北东95.1°±15.4°,穿透壳幔的SKS分裂的快剪切波偏振平均值为北东110.2°±15.8°.而台站分析也显示,地壳内近场资料的快剪切波偏振与SKS快剪切波偏振总是相差十几度以上.不同周期下的Rayleigh面波相速度方位各向异性快波优势方向也同样揭示出随深度增加快波优势方向的变化.这个特征暗示华北地区的壳幔耦合关系可能既不是简单的壳幔解耦型,也不是壳幔强耦合型,可能是两种模式共存的不均匀分布,或者是物理性质介于两者之间的渐变模式.研究表明,在分析穿透整个岩石圈的SKS分裂和地表的GPS观测的基础上,增加揭示地壳各向异性的近场资料剪切波分裂,结合面波的方位各向异性,可以更准确地多方位刻画壳幔各向异性性质,进而探讨壳幔的耦合关系.
According to the data from the seismological network, the national seismograph network and the IRIS station in the Capital area, and by comparing the data of some stations in the flowing North China seismic array, the paper analyzes the seismic anisotropy and obtains the results of the reduction of the influence of local tectonics in North China At least north of North China), the horizontal principal compressive stress of the crust background is 95.1 ° ± 15.4 ° north-east and that of the SKS splitting through the crust and mantle is 110.2 ° ± 15.8 ° north-east The analysis also shows that the fast shear-wave polarization in near-field data in the crust is always more than a dozen degrees above the shear-wave polarization of SKS, and the predominant direction of the azimuthal anisotropy of Rayleigh surface wave velocity in different periods is also revealed This feature suggests that the crust-mantle coupling relationship in North China may not be a simple crust-mantle decoupling type nor a strong coupling type of crust-mantle, and may be an inhomogeneous distribution of coexistence of the two modes , Or a gradual change in the physical properties between the two.Studies have shown that based on the analysis of the SKS splitting and surface GPS observations that have penetrated the entire lithosphere, the near-field data shears revealing the anisotropy of the crust Splitting wave, surface wave azimuthal anisotropy of the binding, can be more accurately characterize the multi-faceted nature of the shell mantle anisotropy, and further explore the relationship between the coupling shell mantle.