Seismic radiation analyses in anisotropic media based on general dislocation source model
Seismic radiation analyses in anisotropic media based on general dislocation source model
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基于一般位错源模型的各向异性介质地震辐射分析
DOI：
10.1093/jge/gxab006
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发表时间：
2021-04
影响因子：
1.4
通讯作者：
Wang Yibo
中科院分区：
文献类型：
--
作者：
Yao Yi;Wang Yibo
各向异性影响震源机制，使其复杂化。剪切运动在各向同性介质中产生纯双耦合（DC）源。而在各向异性介质中，它将产生非直流分量，其中包括各向同性（ISO）和补偿线性矢量偶极子（CLVD）分量。此外，再加上断层运动的多样性，震源可能变得极其复杂。基于位错模型，得到了地震矩张量，并利用矩张量进行了各种分析，包括矩张量分解、辐射方向图、辐射能量比和地震传播特性等。由于介质的各向异性也影响地震波的传播，因此假设震源区是最小的和各向异性的，但传播路径是各向同性的。研究得出了一些有趣的结论。结果表明，在低倾角条件下，各向异性主要影响震源机制，而高倾角条件下，各向异性对极性影响不大。根据矩张量分解，如果只存在ISO或CLVD之一，则可以断言源区是各向异性的，因为ISO分量伴随着各向同性介质中的CLVD分量。直流分量是决定辐射能比的重要因素之一。本文给出了各向异性条件下一般位错震源的震源机制解的一些有价值的发现，有助于认识该次地震的震源特征，为以后的震源机制解反演奠定了基础。
Anisotropy affects the focal mechanism and makes it complicated. A shear motion generates a pure double-couple (DC) source in isotropic media. While in anisotropic media, it will produce non-DC components, which contain isotropic (ISO) and compensated linear vector dipole (CLVD) components. Besides, coupled with the diversity of fault motion, the source may become extremely complicated. In this paper, the seismic moment tensor is obtained based on the dislocation model, and then a variety of analyses are performed with the moment tensor, including moment tensor decomposition, radiation pattern, radiated energy ratio and seismic propagation characteristics. Since the anisotropy of the medium also influences seismic wave propagation, a hypothesis is made that the source region is minimal and anisotropic, but the propagation path is isotropic. The research gives some interesting conclusions. It is found that the anisotropy mainly affects the focal mechanism under low slope angle while high slope angle has little effect on the polarity. In terms of the moment tensor decomposition, if only one of ISO or CLVD exists, it can be asserted that the source region is anisotropic because ISO components are accompanied by CLVD components in isotropy media. As for the DC component, the results indicate it is one of the most important factors for determining the ratio of radiant energy. This paper presents some valuable findings of the focal mechanism of the general dislocation source under anisotropy, which helps to recognise the source characteristics of the earthquake and build solid foundations for the subsequent inversion of the focal mechanism.
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DOI：
10.1190/segam2013-0554.1
发表时间：
2018-09
期刊：
Seg Technical Program Expanded Abstracts
影响因子：
--
作者：
F. Staněk;L. Eisner
通讯作者：
F. Staněk;L. Eisner
影响因子：
56.9
作者：
FROHLICH, C
通讯作者：
FROHLICH, C
影响因子：
3.3
作者：
M. Jost;R. Herrmann
通讯作者：
M. Jost;R. Herrmann
影响因子：
3.3
作者：
Y. Rao;Yanghua Wang
通讯作者：
Y. Rao;Yanghua Wang
影响因子：
3.3
作者：
D. Eaton;Farshid Forouhideh
通讯作者：
D. Eaton;Farshid Forouhideh