scholarly journals Generation of electric field in an earthquake preparation zone

1997 ◽  
Vol 40 (2) ◽  
Author(s):  
R. Teisseyre

Different attempts have been made to explain the generation of the electric currents before an earthquake that take place in an earthquake preparation zone; in some of them the coseismic effects are also included. In this paper we discuss the possibility to construct a model of displacement current generation in an earthquake source zone which combines polarization processes and motion of charged dislocations. Such a process is associated with the transition from isotropic to stress-induced anisotropic properties in an earthquake source zone. Concurrently, we consider the conduction currents related to a high velocity motion of charged dislocations. Another approach related to an electrokinetic model of current generation is also briefly discussed.

2021 ◽  
Author(s):  
Shuai Yang

Abstract In the past scientific cognition, changes in the magnetic field produce electric field, so when there is current and voltage generation, need to have a change in magnetic flux, However, in the process of studying the nature of magnetization, we found that the microscopic formation of a magnetic field is the directional movement of positive and negative charges, under the guidance of this theory, we use other methods, realize the separation of positive and negative charges, observation of induced current generation, this can be used as another way to generate electricity.


2005 ◽  
Vol 23 (4) ◽  
pp. 1347-1354 ◽  
Author(s):  
V. M. Vasyliūnas

Abstract. Fundamentally, the time derivative of the electric field is given by the displacement-current term in Maxwell's generalization of Ampère's law, and the time derivative of the electric current density is given by the generalized Ohm's law. The latter is derived by summing the accelerations of all the plasma particles and can be written exactly, with no approximations, in a (relatively simple) primitive form containing no other time derivatives. When one is dealing with time scales long compared to the inverse of the electron plasma frequency and spatial scales large compared to the electron inertial length, however, the time derivative of the current density becomes negligible in comparison to the other terms in the generalized Ohm's law, which then becomes the equation that determines the electric field itself. Thus, on all scales larger than those of electron plasma oscillations, neither the time evolution of J nor that of E can be calculated directly. Instead, J is determined by B through Ampère's law and E by plasma dynamics through the generalized Ohm's law. The displacement current may still be non-negligible if the Alfvén speed is comparable to or larger than the speed of light, but it no longer determines the time evolution of E, acting instead to modify J. For theories of substorms, this implies that, on time scales appropriate to substorm expansion, there is no equation from which the time evolution of the current could be calculated, independently of ∇xB. Statements about change (disruption, diversion, wedge formation, etc.) of the electric current are merely descriptions of change in the magnetic field and are not explanations.


1971 ◽  
Vol 43 ◽  
pp. 417-421
Author(s):  
A. B. Severny

It is observed that the change of the net magnetic flux associated with flares can exceed 1017 Mx/s, which corresponds according to Maxwell's equation to the e.m.f. ∼ 109 V which is specific for the high energy protons generated in flares. It is shown that this value of e.m.f. can hardly be compensated by e.m.f. of inductance which should appear due to the actually measured motions in a flare generating active region. The values of electric field strength thus found, together with measured values of electric current density (from rotH), leads to an electric conductivity which is 103 times smaller than usually adopted.


Assuming semi-diurnal tidal air flow a solution is made of the atmospheric dynamo problem, taking account both of the direct and transverse conductivities of the ionosphere. The spherical sheet ionosphere is divided into three regions, a narrow equatorial zone, and two wide polar caps, taking appropriate constant conductivities in each region. The current system is similar in shape and phase to that derived on the assumption of uniform (direct) isotropic conductivity, but is considerably more intense than that which would be obtained without the existence of transverse (Hall) conductivity. The electric field system is very different, however, from that derived on this (isotropic) assumption. An abnormally large east-west current is found at the equator, which appears to provide the explanation of the anomalous magnetic variation in this region. Curves are given showing the distribution of the field and current components.


1997 ◽  
Vol 07 (08) ◽  
pp. 1085-1120 ◽  
Author(s):  
P. Ciarlet ◽  
E. Sonnendrücker

In many cases, the numerical resolution of Maxwell's equations is very expensive in terms of computational cost. The Darwin model, an approximation of Maxwell's equations obtained by neglecting the divergence free part of the displacement current, can be used to compute the solution more economically. However, this model requires the electric field to be decomposed into two parts for which no straightforward boundary conditions can be derived. In this paper, we consider the case of a computational domain which is not simply connected. With the help of a functional framework, a decomposition of the fields is derived. It is then used to characterize mathematically the solutions of the Darwin model on such a domain.


Author(s):  
Y. J. Gu ◽  
Q. Yu ◽  
O. Klimo ◽  
T. Zh. Esirkepov ◽  
S. V. Bulanov ◽  
...  

Fast magnetic field annihilation in a collisionless plasma is induced by using TEM(1,0) laser pulse. The magnetic quadrupole structure formation, expansion and annihilation stages are demonstrated with 2.5-dimensional particle-in-cell simulations. The magnetic field energy is converted to the electric field and accelerate the particles inside the annihilation plane. A bunch of high energy electrons moving backwards is detected in the current sheet. The strong displacement current is the dominant contribution which induces the longitudinal inductive electric field.


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