Lunar near‐surface shear wave velocities at the Apollo Landing Sites as inferred from spectral amplitude ratios
Lunar near‐surface shear wave velocities at the Apollo Landing Sites as inferred from spectral amplitude ratios
复制标题
从谱振幅比推断出阿波罗登陆点的月球近地表剪切波速度
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
H. Dorman
中科院分区：
文献类型：
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作者：
P. Horváth;G. Latham;Yosio Nakamura;H. Dorman
重新检查长周期地震图的水平与垂直振幅比，以确定阿波罗12号，14号，15号和16号月球着陆点的剪切波速度分布。平均频谱比，计算出的影响信号的数量，进行了比较，计算的基本模式瑞利波在介质中的均匀，各向同性，水平层的频谱比。最佳拟合模型的剪切速度在不同的网站彼此相似，除了底层站14，从所有网站的平均相差不超过20%。剪切速度从地表的40 m/s增加到各个站点95 m至160 m深度处的约400 m/s。在此深度范围内，速度-深度函数很好地由两个分段线性段表示，尽管不能排除一阶不连续性的存在。
The horizontal-to-vertical amplitude ratios of the long-period seismograms are reexamined to determine the shear wave velocity distributions at the Apollo 12, 14, 15, and 16 lunar landing sites. Average spectral ratios, computed from a number of impact signals, were compared with spectral ratios calculated for the fundamental mode Rayleigh waves in media consisting of homogeneous, isotropic, horizontal layers. The shear velocities of the best fitting models at the different sites resemble each other and differ from the average for all sites by not more than 20% except for the bottom layer at station 14. The shear velocities increase from 40 m/s at the surface to about 400 m/s at depths between 95 and 160 m at the various sites. Within this depth range the velocity-depth functions are well represented by two piecewise linear segments, although the presence of first-order discontinuities cannot be ruled out.