Likely P‐to‐S Conversion at the Core‐Mantle Boundary Extracted From Array Processing of Noise Records
Likely P‐to‐S Conversion at the Core‐Mantle Boundary Extracted From Array Processing of Noise Records
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DOI：
10.1029/2021gl097034
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发表时间：
2022-03
影响因子：
5.2
通讯作者：
Tianze Liu;P. Shearer
中科院分区：
文献类型：
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作者：
Tianze Liu;P. Shearer
在过去的几十年中，地震噪声作为地震信号的有力补充被广泛用于地球结构成像。虽然地震噪声场包含面波和体波分量，但由于面波振幅大，大多数以前的研究都集中在面波上。在这里，我们使用阵列分析来识别作为PKP波传播的体波噪声。我们发现，通过在包含PKP噪声信号的时间窗口中对阵列堆叠的水平分量和垂直分量数据进行互相关，我们提取了可能代表PKS-PKP的相位，即PKS和PKP之间的差分相位。该阶段可用于剪切波分裂分析。我们的研究结果还表明，体波噪声的来源在空间和时间上都是非常不均匀的，这应该在未来的研究中使用体波噪声来成像地球结构。
Seismic noise has been widely used to image Earth's structure in the past decades as a powerful supplement to earthquake signals. Although the seismic noise field contains both surface‐wave and body‐wave components, most previous studies have focused on surface waves due to their large amplitudes. Here, we use array analyses to identify body‐wave noise traveling as PKP waves. We find that by cross‐correlating the array‐stacked horizontal‐ and vertical‐component data in the time windows containing the PKP noise signals, we extract a phase likely representing PKS‐PKP, the differential phase between PKS and PKP. This phase can potentially be used for shear‐wave‐splitting analysis. Our results also suggest that the sources of body‐wave noise are extremely heterogeneous in both space and time, which should be accounted for in future studies using body‐wave noise to image Earth structure.