A review and upgrade of the lithospheric dynamics in context of the seismo-electromagnetic theory

Venegas-Aravena, Patricio; Cordaro, E. G.; Laroze, David

doi:10.5194/nhess-19-1639-2019

Cited by 15 publications

(16 citation statements)

References 73 publications

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“…In this paper, we adopted the electrokinetic coseismic effect as the formation mechanism of earthquake-induced EM waves in the lithosphere; however, it is only one of the credible theories attempting to elucidate the EM radiation. Other possible theories include the piezoelectric effect, motion of charged edge dislocations (MCD) [52] and stress-induced electromagnetic emissions. In addition, the electrokinetic effect is insufficient to explain the abnormal phenomena of ULF, ELF and VLF observed by researchers before earthquakes and the pre-earthquake seismic EM radiation mechanism has not yet formed a convincing simulation model.…”

Section: Discussionmentioning

confidence: 99%

Numerical Study of Global ELF Electromagnetic Wave Propagation with Respect to Lithosphere–Atmosphere–Ionosphere Coupling

et al. 2021

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Before and after earthquakes, abnormal physical and chemical phenomena can be observed by gathering ground-based and satellite data and interpreted by the lithosphere–atmosphere–ionosphere coupling (LAIC) mechanism. In this study, we focused on the mechanism of LAIC electromagnetic radiation and investigated the seismic electromagnetic (EM) wave generated in the lithosphere by earthquakes and its global propagation process from the lithosphere through the atmosphere and into the bottom of ionosphere, in order to analyze the abnormal disturbance of ground-based and space-based observation results. First, analytic formulas of the electrokinetic effect were used to simulate the generation and propagation process of the seismic EM wave in the lithosphere, interpreted as the conversion process of the seismic wave and EM wave in porous media. Second, we constructed a three-dimensional Earth–ionosphere waveguide by applying the finite-difference time-domain (FDTD) algorithm to model the global propagation process of the seismic EM wave into the atmosphere and cavity between the bottom of the ionosphere and the surface of the Earth. By combining the model of the electrokinetic effect in the lithosphere with the numerical model of the Earth–ionosphere waveguide in the atmosphere and ionosphere, we numerically simulated the global transmission process of extremely low-frequency (ELF: 3 Hz–3000 Hz) EM waves which are related to earthquakes. The propagation parameters of coseismic ELF EM waves with different duration times and center frequencies were analyzed and summarized. The simulation results demonstrate that the distribution characteristics of an electric field along longitude, latitude and altitude with time are periodic and the time interval during which an EM wave travels around the whole Earth is approximately 0.155 s when adopting the conductivity of the knee profile. We also compared the observation data with the simulation results and found that the attenuating trends of the ELF electric field are consistent. This proposed ELF EM wave propagation model of lithosphere–atmosphere–ionosphere coupling is very promising for the explanation of abnormal disturbances of ground-based and space-based observation results of ELF EM fields which are associated with earthquakes.

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Section: Discussionmentioning

confidence: 99%

Numerical Study of Global ELF Electromagnetic Wave Propagation with Respect to Lithosphere–Atmosphere–Ionosphere Coupling

et al. 2021

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“…14with those found by other researchers. If we use the fault values µ sm = 3.3 × 10 10 Pa, d = 4 m and S = 450 × 120 km 2 (Vigny et al, 2011;Yue et al, 2014); the granite rock and brittle properties µ m = 13.5 × 10 −7 N A −2 (Scott, 1983), J = 5 × 10 −6 A m −2 (Tzanis and Vallianatos, 2002), l min = 10 −3 m (Shah, 2011) and D = 2.6 (Turcotte, 1997); and the magnetic data B cs ≈ 0.1 nT at r ≈ 250 km (…”

Section: Stress Drop and Total Friction Coefficient -Spatial-temporalmentioning

confidence: 99%

The spatial–temporal total friction coefficient of the fault viewed from the perspective of seismo-electromagnetic theory

Venegas-Aravena

Cordaro

Laroze

2020

Nat. Hazards Earth Syst. Sci.

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Abstract. Recently, it has been shown theoretically how the lithospheric stress changes could be linked with magnetic anomalies, frequencies, spatial distribution and the magnetic-moment magnitude relation using the electrification of microfractures in the semibrittle–plastic rock regime (Venegas-Aravena et al., 2019). However, this seismo-electromagnetic theory has not been connected with the fault's properties in order to be linked with the onset of the seismic rupture process itself. In this work we provide a simple theoretical approach to two of the key parameters for seismic ruptures which are the friction coefficient and the stress drop. We use sigmoidal functions to model the stress changes in the nonelastic regime within the lithosphere. We determine the temporal changes in frictional properties of faults. We also use a long-term friction coefficient approximation that depends on the fault dip angle and four additional parameters that weigh the first and second stress derivative, the spatial distribution of the nonconstant stress changes, and the stress drop. We found that the friction coefficient is not constant in time and evolves prior to and after the earthquake occurrence regardless of the (nonzero) weight used. When we use a dip angle close to 30∘ and the contribution of the second derivative is more significant than that of the first derivative, the friction coefficient increases prior to the earthquake. During the earthquake event the friction drops. Finally, the friction coefficient increases and decreases again after the earthquake occurrence. It is important to mention that, when there is no contribution of stress changes in the semibrittle–plastic regime, no changes are expected in the friction coefficient.

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“…The appropriate value for ν depends on the kind of data under consideration. Thus, for instance, the application of this method to the minute variations of the stock market yielded ν = 30 (half an hour) as a significant time window to establish tendencies in this economical activity (Vogel and Saravia, 2014). In the case of seismic sequences ordered by real time, time windows between ν = 24 and ν = 96 were investigated finding that ν = 24 is appropriate to deal with seismic activity (Vogel et al, 2017a).…”

Section: Shannon Entropymentioning

confidence: 99%

“…It has been used in less drastic data evolution revealing different regimes or behaviors of a variety of systems. The first of such applications was in econophysics dealing with stock markets (Vogel and Saravia, 2014) and pension systems (Vogel et al, 2015). The alteration of blood pressure parameters was also investigated using wlzip (Contreras et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Measuring the seismic risk along the Nazca–South American subduction front: Shannon entropy and mutability

Vogel

Brevis

Pastén

et al. 2020

Nat. Hazards Earth Syst. Sci.

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Abstract. Four geographical zones are defined along the trench that is formed due to the subduction of the Nazca plate underneath the South American plate; they are denoted A, B, C and D from north to south; zones A, B and D had a major earthquake after 2010 (magnitude over 8.0), while zone C has not, thus offering a contrast for comparison. For each zone, a sequence of intervals between consecutive seisms with magnitudes greater than or equal to 3.0 is set up and then characterized by Shannon entropy and mutability. These methods show a correlation after a major earthquake in what is known as the aftershock regime but show independence otherwise. Exponential adjustments to these parameters reveal that mutability offers a wider range for the parameters to characterize the recovery compared to the values of the parameters defining the background activity for each zone before a large earthquake. It is found that the background activity is particularly high for zone A, still recovering for zone B, reaching values similar to those of zone A in the case of zone C (without recent major earthquake) and oscillating around moderate values for zone D. It is discussed how this can be an indication of more risk of an important future seism in the cases of zones A and C. The similarities and differences between Shannon entropy and mutability are discussed and explained.

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A review and upgrade of the lithospheric dynamics in context of the seismo-electromagnetic theory

Cited by 15 publications

References 73 publications

Numerical Study of Global ELF Electromagnetic Wave Propagation with Respect to Lithosphere–Atmosphere–Ionosphere Coupling

Numerical Study of Global ELF Electromagnetic Wave Propagation with Respect to Lithosphere–Atmosphere–Ionosphere Coupling

The spatial–temporal total friction coefficient of the fault viewed from the perspective of seismo-electromagnetic theory

Measuring the seismic risk along the Nazca–South American subduction front: Shannon entropy and mutability

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