Fully nonlinear inversion of fundamental mode surface waves for a global crustal model
Fully nonlinear inversion of fundamental mode surface waves for a global crustal model
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DOI：
10.1029/2007gl030989
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发表时间：
2007-08
影响因子：
5.2
通讯作者：
Ueli Meier;Andrew Curtis;J. Trampert
中科院分区：
文献类型：
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作者：
Ueli Meier;Andrew Curtis;J. Trampert
我们使用神经网络来寻找全球地壳参数的一维边缘概率密度函数（pdf）。完整的后验和先验pdf的信息内容可以量化参数受数据约束的程度。我们反演了地壳厚度pdf的基模Love和Rayleigh波相位和群速度图，并且与垂直平均地壳剪切波速度无关。利用相速度周期T > 35 s、群速度周期T > 18 s的面波资料，可以很好地约束陆壳莫霍面深度和垂直平均横波速度，但不能分辨洋壳垂直平均横波速度。后者是先验约束CRUST2.0。我们表明，由此产生的模型可以计算全球地壳校正面波层析成像的周期T > 50 s的相速度和T > 60 s的群速度。
We use neural networks to find 1‐dimensional marginal probability density functions (pdfs) of global crustal parameters. The information content of the full posterior and prior pdfs can quantify the extent to which a parameter is constrained by the data. We inverted fundamental mode Love and Rayleigh wave phase and group velocity maps for pdfs of crustal thickness and independently of vertically averaged crustal shear wave velocity. Using surface wave data with periods T > 35 s for phase velocities and T > 18 s for group velocities, Moho depth and vertically averaged shear wave velocity of continental crust are well constrained, but vertically averaged shear wave velocity of oceanic crust is not resolvable. The latter is a priori constrained by CRUST2.0. We show that the resulting model allows to compute global crustal corrections for surface wave tomography for periods T > 50 s for phase velocities and T > 60 s for group velocities.