Electromagnetic field generated by an earthquake source due to motional induction in 3D stratified media, and application to 2008 M w 6.1 Qingchuan earthquake

2021 ◽  
Author(s):  
Jie Zhao ◽  
Yongxin Gao ◽  
Ji Tang ◽  
Simon Klemperer ◽  
Jian Wen ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Earthquake Source ◽  
Stratified Media ◽  
Motional Induction

scholarly journals Electromagnetic scattering from cylindrically and spherically stratified bodies

1968 ◽  
Vol 46 (12) ◽  
pp. 1463-1468 ◽  
Author(s):  
R. W. Latham
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Scattering ◽  
Wave Scattering ◽  
Inhomogeneous Media ◽  
Stratified Media ◽  
Scattering Problems ◽  
Embedding Method ◽  
Invariant Embedding ◽  
Invariant Embedding Method ◽  
Constitutive Parameters

A method is developed for calculating the electromagnetic field scattered by certain types of bodies. The bodies consist of inhomogeneous media whose constitutive parameters vary only with the distance from some axis or point of symmetry. The method consists of an extension of the invariant embedding method for treating wave-scattering problems. This method, familiar in the case of plane stratified media, is extended to handle cylindrically and spherically stratified media.

An Analytic Algorithm for Dipole Electromagnetic Field in Fully Anisotropic Planar-Stratified Media

2020 ◽  
pp. 1-12
Author(s):  
Decheng Hong ◽  
Na Li ◽  
Wei Han ◽  
Qiwei Zhan ◽  
Kirill Zeyde ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Stratified Media

Electromagnetic responses to an earthquake source due to the motional induction effect in a 2-D layered model

2019 ◽  
Vol 219 (1) ◽  
pp. 563-593 ◽  
Author(s):  
Yongxin Gao ◽  
Dongdong Wang ◽  
Jian Wen ◽  
Hengshan Hu ◽  
Xiaofei Chen ◽  
...  
Keyword(s):  
Geomagnetic Field ◽  
Moment Tensor ◽  
Vertical Plane ◽  
Correction Method ◽  
Earthquake Source ◽  
P Wave ◽  
Induction Effect ◽  
Layered Model ◽  
Motional Induction ◽  
Horizontal Electric Dipole

Summary Movement of the conductive earth medium in the ambient geomagnetic field can generate an electromotive force and a motional induction current, which further cause the disturbances of the electromagnetic (EM) fields. Such a mechanoelectric coupling is known as the motional induction (MI) effect and has been proposed to be a possible mechanism for the generation of the observed EM signals during earthquakes. In this paper, we study the EM responses to an earthquake source due to such a MI effect in a 2-D horizontally layered model. First we transform the governing equations that couple the elastodynamic equations and Maxwell equations into a set of first-order ordinary depth-dependent differential equations. Then we solve the seismic and EM responses to a moment tensor source. Finally, we transform the 2-D seismic and EM responses to 3-D responses using a simple amplitude correction method. We conduct several numerical examples to investigate the properties of the EM signals generated by the earthquake source. The results show that two types of EM signals can be observed. The first one is the coseismic electric/magnetic field that accompanies the seismic P and S waves as well as the Rayleigh wave. The second one is the early EM signal which arrives before the P wave. The numerical results show that the EM signals change with the inclination angle of the geomagnetic field, the azimuth angle between the wave propagation plane and the geomagnetic vertical plane, and the medium conductivity. Increase in the conductivity can enhance the coseismic electric and magnetic signals. Our simulation also shows that an EM wave can be generated by a seismic wave at the interface separating two different media. The radiation pattern of the interface EM wave generated by a P wave is similar to that of a horizontal electric dipole located on the interface.

scholarly journals Short-term earthquake forecast

2021 ◽  
Vol 3 (1) ◽  
pp. 92-99
Author(s):  
Vladislav Voleysho
Keyword(s):  
Electromagnetic Field ◽  
Geographical Location ◽  
Earthquake Source ◽  
Source Zone ◽  
Seismogenic Structure ◽  
Short Term ◽  
Earthquake Forecast ◽  
Strong Earthquakes ◽  
Term Prediction ◽  
Short Term Prediction

In the manuscript, a tectonomagnetic model of forming the source zone of a strong earthquake is presented from the position of the electromagnetic field of Earth. The model is based on the idea of magnetic interaction between geological blocks screening, when the bond to each other by adhesion, a flux of abyssal fluids with the formation of a seismogenic structure. The source zone of strong earthquakes formed inside the seismogenic structure is followed by the development of an anomalous electromagnetic field. The existence of the deterministic cause-and-effect relationship between anomalous electromagnetic field inside the formed earthquake source and a change in atmospheric pressure determines the possibilities of conducting short-term prediction of time, place, and force of the earthquake. Registration of the earthquake source zone by barometric method during hydrogeodynamic monitoring makes it possible to make short-term predictions of it by time, place, and force. The substantiation and examples are given for short-term prediction of time, geographical location, and force of strong earthquakes in basic seismically active regions of Russia.

Comparison of high- and low-frequency electromagnetic field analysis

1993 ◽  
Vol 3 (3) ◽  
pp. 363-371 ◽  
Author(s):  
A. Konrad ◽  
I. A. Tsukerman
Keyword(s):  
Electromagnetic Field ◽  
Low Frequency ◽  
Field Analysis
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