On the recent advances in the study of seismic electric signals (VAN method)

2006 ◽  
Vol 31 (4-9) ◽  
pp. 189-197 ◽  
Author(s):  
P.A. Varotsos ◽  
N.V. Sarlis ◽  
E.S. Skordas
Keyword(s):  
Seismic Electric Signals ◽  
Recent Advances ◽  
Van Method ◽  
Electric Signals

Pulsed Charge Model of Fault Behavior Producing Seismic Electric Signals (SES)

1997 ◽  
Vol 07 (03) ◽  
pp. 153-164 ◽  
Author(s):  
Motoji Ikeya ◽  
Shunji Takaki ◽  
Hiroshi Matsumoto ◽  
Atsushi Tani ◽  
Takahide Komatsu
Keyword(s):  
Power Spectra ◽  
Charge Generation ◽  
Electric Pulses ◽  
Charge Densities ◽  
Seismic Electric Signals ◽  
Atmospheric Molecules ◽  
Fault Behavior ◽  
Charge Model ◽  
Seismic Stress ◽  
Electric Signals

The electromagnetic (EM) behavior of a geological fault is postulated to follow the mathematical model of a fault in seismology that illustrates seismic EM anomalies EMAs). Charge densities, +q and -q in C/m2 are generated at a fault zone by the change in seismic stress, α as d q/ d t = -α d σ/ d t - q/∊ρ, where σ,∊ and ρ are the charge generation constants measured in C/N, dielectric constant and reisitivity of bedrocks, respectively. A fault of length, 2a, plane area, A and the displacement or rupture time, τ gives pulsed charge densities, +q(t) and -q(t), or a dipole moment of P(t) = 2aAq(t) = αM0[∊ρ/(τ - ∊ρ) - exp (-t/∊ρ)] using the earthquake moment M0. Maxwell's equations for this dipole in a conductive earth give power spectra of EM waves at diferrent distances. Seismic electric signals (SES) including the DC VAN method can be explained as EM waves. Electrons with density n in the atmosphere are accelerated by the electric field and travel a distance l. resulting in the exictation and ionization of atmospheric molecules leading to earthquake lightning (EQL). They also polarize the ionosphere by disturbing the transmission of EM waves prior to an earthquake and artificial electronic noises. The same pulsed field surprised eels and hamsters, suggesting seismic anomalous animal ehavious animal behavior (SAAB) as electro-physiological responses to the stimuli of electric pulses.

scholarly journals Comments on the generation mechanism of Seismic Electric Signals

2011 ◽  
Vol 11 (12) ◽  
pp. 3093-3096 ◽  
Author(s):  
E. Dologlou
Keyword(s):  
Power Law ◽  
Thermodynamic Model ◽  
Stress Drop ◽  
Lead Time ◽  
Generation Mechanism ◽  
Laboratory Measurements ◽  
Bulk Properties ◽  
Seismic Electric Signals ◽  
Electric Signals ◽  
Recent Laboratory

Abstract. Recent laboratory measurements on rocks under varying pressure lead to results which strengthen a model suggested by the author for the explanation of the power law relation that interconnects the lead time of Seismic Electric Signals and earthquake stress drop. In addition, recent applications of a thermodynamic model that interrelates the defect parameters in materials of geophysical interest and their bulk properties open a new window to further advance the aforementioned explanation.

scholarly journals Electrical precursors of earthquakes in Aegean Sea during the last decade (1997–2007)

2008 ◽  
Vol 8 (1) ◽  
pp. 123-128 ◽  
Author(s):  
E. Dologlou ◽  
V. Hadjicontis ◽  
C. Mavromatou
Keyword(s):  
Lead Time ◽  
Aegean Sea ◽  
Time Difference ◽  
Lead Times ◽  
Main Interest ◽  
Seismic Electric Signals ◽  
Precursors Of Earthquakes ◽  
Electric Signals ◽  
Large Earthquakes ◽  
Regional Tectonics

Abstract. The purpose of this study is to investigate some properties of the Seismic Electric Signals (SES) that preceded large earthquakes which occurred in the Aegean Sea (24–27)° E, (37–40)° N, during the last decade. Our main interest is focused on the important parameter of the lead time Δt, which is the time difference between the occurrence of the earthquake and the detection of the associated SES signal. Two groups of lead times, a short (i.e. Δt~ some weeks) and a long one (Δt~ some months) have been observed. We examine whether this difference could be related to the regional tectonics. Furthermore the property of SES selectivity is discussed.

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