Geometry-preserving full-waveform tomography and its application in the Longmen Shan area
Geometry-preserving full-waveform tomography and its application in the Longmen Shan area
复制标题
保形全波形层析成像及其在龙门山地区的应用
DOI：
10.1007/s11430-021-9849-5
复制
发表时间：
2022-01
影响因子：
5.7
通讯作者：
Yun Chen
中科院分区：
文献类型：
--
作者：
Xingpeng Dong;Dinghui Yang;Hejun Zhu;Yun Chen
经典的基于L2范数的波形层析成像经常受到无法克服的周期跳跃问题的困扰;因此，迭代反演福尔斯落入局部最小值，产生错误的图像。根据最优运输理论，采用了一种基于二次Wasserstein度量（W2-范数）的新的几何保持失配函数，提高了反问题的稳定性和凸性.数值实验表明，基于W2范数的全波形层析成像算法比基于L2范数的全波形层析成像算法具有更大的收敛半径和更快的收敛速度，能够有效地缓解跳周问题。将该方法应用于龙门山地区，得到了可靠的岩石圈速度模型。层析成像结果表明，四川盆地结晶地壳楔入青藏高原地壳内部，青藏高原东部中下地壳剪切波速度较低，表明韧性地壳流动和碎屑岩间强烈的相互作用共同控制了龙门山的隆升行为。此外，我们发现大地震（例如，汶川地震和芦山地震）不仅发生在高、低速区的交界处，而且也发生在正向负径向各向异性的过渡区。这些发现提高了我们对该地区大地震机制的理解。
Classic L2-norm-based waveform tomography is often plagued by insurmountable cycle skipping problems; as a result, the iterative inversion falls into local minima, yielding erroneous images. According to the optimal transportation theory, we adopt a novel geometry-preserving misfit function based on the quadratic Wasserstein metric (W2-norm), which improves the stability and convexity of the inverse problem. Numerical experiments illustrate that W2-norm-based full-waveform tomography has a larger convergence radius and a faster convergence rate than the L2-norm and can effectively mitigate cycle skipping issues. We apply this method to the Longmen Shan area and obtain a reliable lithospheric velocity model. Our tomographic results indicate that the crystalline crust underlying the Sichuan Basin wedges into the crustal interior of the Tibetan Plateau, and the mid-lower crust of the eastern Tibetan Plateau is characterized by low shear-wave velocities, indicating that ductile crustal flow and strong interactions between terranes jointly dominate the uplift behavior of the Longmen Shan. Furthermore, we find that large earthquakes (e.g., the Wenchuan and Lushan events) occur not only at the junction between high- and low-velocity regions but also in the transition zone from positive to negative radial anisotropy. These findings improve our understanding of the mechanism responsible for large earthquakes in this region.
登录
查看更多内容
西藏东南部下方的 P 波层析图像：2008 年汶川地震机制研究
DOI：
10.1007/s11430-010-4037-5
发表时间：
2010-09
期刊：
Science China Earth Sciences
影响因子：
--
作者：
Wei Wei;Sun RuoMei;Shi YaoLin
通讯作者：
Shi YaoLin
基于均匀采样无放回集合卡尔曼滤波方法的全波形反演
影响因子：
18.9
作者：
Wang Jian;Yang Dinghui;Jing Hao;Wu Hao
通讯作者：
Wu Hao
影响因子：
2.3
作者：
N. Rawlinson;S. Pozgay;S. Fishwick
通讯作者：
N. Rawlinson;S. Pozgay;S. Fishwick
DOI：
10.4310/ajm.2016.v20.n2.a7
发表时间：
2013-02
期刊：
arXiv: Geometric Topology
影响因子：
--
作者：
X. Gu;F. Luo;Jian Sun;S. Yau
通讯作者：
X. Gu;F. Luo;Jian Sun;S. Yau
影响因子：
1.8
作者：
He Xiangli;Li Haibing;Wang Huan;Z. Lei;S. Zhiming;Si Jialiang
通讯作者：
He Xiangli;Li Haibing;Wang Huan;Z. Lei;S. Zhiming;Si Jialiang