Green’s Functions for Surface Waves in a Generic Velocity Structure
Green’s Functions for Surface Waves in a Generic Velocity Structure
复制标题
通用速度结构中表面波的格林函数
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
S. Atiganyanun
中科院分区：
文献类型：
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作者：
V. Tsai;S. Atiganyanun
计算面波速度和相关位移/应力本征函数以及绿色函数的方法已经建立了几十年。然而，据我们所知，还没有人记录过常用经验缩放对这些属性的定量评估。例如，目前不可能采用给定的剪切波速度对深度的幂律依赖关系，并查找相速度对频率的相应依赖关系，或绿色函数表面位移。我们在文献中解决了这一差距，并在这里为近地表速度结构的几个常用经验公式提供了相速度和绿色函数振幅的明确定量精确表达式。这些精确的表达式被发现在使用浅层相速度的应用中以及在解释来自近地表过程的地震振幅或振幅比的应用中是立即有用的，所述近地表过程例如河流运输、冰震、滑坡和火山震颤。
Methodologies for calculating surface‐wave velocities and the associated displacement/stress eigenfunctions and Green’s functions have been well established for many decades. However, to our knowledge, no one has ever documented a quantitative evaluation of these properties for commonly used empirical scalings. For example, it is currently not possible to take a given power‐law dependence of shear‐wave velocity on depth and look up the corresponding dependence of phase velocity on frequency, or Green’s function surface displacement. We address this gap in the literature and here provide explicit quantitatively accurate expressions for phase velocities and Green’s function amplitudes for a few commonly used empirical formulas for near‐surface velocity structure. These exact expressions are found to be immediately useful in applications that use shallow phase velocities and also in applications that interpret seismic amplitudes or amplitude ratios from near‐surface processes such as fluvial transport, icequakes, landslides, and volcanic tremor.