Simultaneous inversion for crustal thickness and anisotropy by multiphase splitting analysis of receiver functions
Simultaneous inversion for crustal thickness and anisotropy by multiphase splitting analysis of receiver functions
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DOI：
10.1093/gji/ggaa435
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发表时间：
2020-09
影响因子：
2.8
通讯作者：
F. Link;G. Rümpker;A. Kaviani
中科院分区：
文献类型：
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作者：
F. Link;G. Rümpker;A. Kaviani
我们提出了一种技术，以获得强大的估计地壳厚度和弹性特性，包括各向异性，从剪切波分裂接收器功能的转换相位。我们结合联合收割机叠加程序与地壳转换的Ps相和它的第一个混响，PpPs相，在那里我们还允许一个预定义的倾斜莫霍面的分裂效果的校正方案。两个阶段的合并稳定的分析过程，并允许同时解决地壳厚度，平均P波与S波速度的比率，各向异性的百分比和快轴方向。堆叠是基于使用基于射线的算法计算的到达时间和极化。合成试验表明，该技术的鲁棒性和其适用性的构造环境中的莫霍面倾角是显着的。这些测试还表明，浸渍层边界的影响可能会覆盖一个可能的各向异性签名。为了约束我们的结果的不确定性，我们进行统计测试的基础上，自举方法。我们通过比较时差校正后叠加振幅的相干性来区分不同的模型类。我们将新技术应用于实际数据的例子，从不同的构造制度，并显示堆叠接收器功能的相干性可以得到改善，当各向异性和倾斜莫霍面包括在分析中。这些例子强调了统计分析在处理堆叠程序和潜在的模糊解决方案时的优势。
We present a technique to derive robust estimates for the crustal thickness and elastic properties, including anisotropy, from shear wave splitting of converted phases in receiver functions. We combine stacking procedures with a correction scheme for the splitting effect of the crustal converted Ps-phase and its first reverberation, the PpPs-phase, where we also allow for a predefined dipping Moho. The incorporation of two phases stabilizes the analysis procedure and allows to simultaneously solve for the crustal thickness, the ratio of average P- to S-wave velocities, the percentage of anisotropy and the fast-axis direction. The stacking is based on arrival times and polarizations computed using a ray-based algorithm. Synthetic tests show the robustness of the technique and its applicability to tectonic settings where dip of the Moho is significant. These tests also demonstrate that the effects of a dipping layer boundary may overprint a possible anisotropic signature. To constrain the uncertainty of our results we perform statistical tests based on a bootstrapping approach. We distinguish between different model classes by comparing the coherency of the stacked amplitudes after moveout correction. We apply the new technique to real-data examples from different tectonic regimes and show that coherency of the stacked receiver functions can be improved, when anisotropy and a dipping Moho are included in the analysis. The examples underline the advantages of statistical analyses when dealing with stacking procedures and potentially ambiguous solutions.