Existence of evanescent electromagnetic waves resulting from seismoelectric conversion at a solid–porous interface
Existence of evanescent electromagnetic waves resulting from seismoelectric conversion at a solid–porous interface
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固体-多孔界面上的震电转换产生的倏逝电磁波的存在
DOI：
10.1093/gji/ggv400
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发表时间：
2016
影响因子：
2.8
通讯作者：
Chen Xiaofei
中科院分区：
文献类型：
--
作者：
Ren Hengxin;Huang Qinghua;Chen Xiaofei
采用由固体和多孔材料组成的两半空间模型，数值研究了固体-孔洞界面上的地震电转换。首先，比较了低孔隙双层模型和均匀全空间模型中的波场。地震波的一致性是对我们程序的验证。我们对记录在界面附近固体区域的准同震电磁(EM)信号很感兴趣，因为它们似乎伴随着地震波。然后，对一个普通的双层模型进行了进一步的数值模拟。在时间切片快照和理论分析的基础上，我们确定准同震电磁信号本质上是非同震电动场，包括辐射电磁波和瞬逝电磁波。瞬逝电磁波是由入射角度大于临界角到达界面的地震波引起的。当离开界面时，这些波比辐射电磁波衰减得更快。在多孔层中，除非将消失的电磁波从同震波信号中分离出来，否则很难识别它们。这一发现可能是以前的地震电学研究中没有识别出瞬逝电磁波的原因。认识到在界面上的震电转换可以产生瞬逝波和电磁波这一事实，可能会导致对震电耦合现象的全面理解和更好的解释。
Adopting a model with two half-spaces that consist of solid and porous materials, we numerically investigate the seismoelectric conversion at the solid–porous interface. First, the wave fields in a low-porosity two-layer model are compared with those in a homogeneous full-space model. The consistency of seismic waves is a validation of our program. We are interested in the quasi-coseismic electromagnetic (EM) signals recorded in the solid area near the interface because they seemingly accompany seismic waves. Then, further numerical simulations on an ordinary two-layer model are conducted. On the basis of time slice snapshots and theoretical analysis, we determine that quasi-coseismic EM signals are essentially non-coseismic EM fields, which include radiation and evanescent EM waves. Evanescent EM waves are induced by the seismic waves that arrive at the interface with the incident angle greater than the critical angle. These waves decay faster than radiation EM waves when moving away from the interface. In the porous layer, evanescent EM waves can hardly be recognized unless they are separated from coseismic EM signals. This finding can be the reason why evanescent EM waves have not been identified in previous seismoelectric studies. Awareness of the fact that seismoelectric conversion at an interface can generate evanescent and EM waves is likely to result in a comprehensive understanding and improved interpretation of the seismoelectric coupling phenomenon.
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影响因子：
--
作者：
A. Revil;H. Schwaeger;L. Cathles;P. Manhardt
通讯作者：
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影响因子：
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作者：
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通讯作者：
A. Revil;G. Barnier;M. Karaoulis;P. Sava;A. Jardani;B. Kulessa
影响因子：
2.6
作者：
Zhenya Zhu;M. Nafi Toksöz
通讯作者：
Zhenya Zhu;M. Nafi Toksöz