Near-surface compressional and shear wave speeds constrained by body-wave polarization analysis
Near-surface compressional and shear wave speeds constrained by body-wave polarization analysis
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DOI：
10.1093/gji/ggy072
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发表时间：
2018-06
影响因子：
2.8
通讯作者：
Sunyoung Park;M. Ishii
中科院分区：
文献类型：
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作者：
Sunyoung Park;M. Ishii
提出了一种约束近地表地震结构的新技术，该技术将体波偏振方向与地震台正下方的波速联系起来。 P波偏振方向仅对横波速度敏感而对压缩波速度不敏感，而S波偏振方向对两种波速均敏感。该技术应用于日本高灵敏度地震仪网络的数据，结果表明，偏振分析获得的波速估计与钻孔测量的波速估计一致。波速的横向变化与地形和火山等地质和物理特征相关。该技术需要最少的计算资源，并且可用于任意数量的三分量远震记录，为对最浅（∼100 m）地壳结构进行非侵入性且廉价的研究提供了机会。
A new technique to constrain near-surface seismic structure that relates body-wave polarization direction to the wave speed immediately beneath a seismic station is presented. TheP-wave polarization direction is only sensitive to shear wave speed but not to compressional wave speed, while theS-wave polarization direction is sensitive to both wave speeds. The technique is applied to data from the High-Sensitivity Seismograph Network in Japan, and the results show that the wave speed estimates obtained from polarization analysis are compatible with those from borehole measurements. The lateral variations in wave speeds correlate with geological and physical features such as topography and volcanoes. The technique requires minimal computation resources, and can be used on any number of three-component teleseismic recordings, opening opportunities for non-invasive and inexpensive study of the shallowest (∼100 m) crustal structures.