scholarly journals In connection with identification of VLF emissions before L'Aquila earthquake

2012 ◽  
Vol 12 (4) ◽  
pp. 1009-1015 ◽  
Author(s):  
M. K. Kachakhidze ◽  
Z. A. Kereselidze ◽  
N. K. Kachakhidze ◽  
G. T. Ramishvili ◽  
V. J. Kukhianidze
Keyword(s):  
Electromagnetic Emission ◽  
Retrospective Data ◽  
L’Aquila Earthquake ◽  
Frequency Range ◽  
The Earth ◽  
Atmosphere System ◽  
Data Application ◽  
Electromagnetic Oscillations ◽  
Vlf Emissions ◽  
Geomagnetic Perturbations

Abstract. The present paper deals with an attempt to check the theoretical model of self-generated seismo-electromagnetic oscillations of LAI system on the basis of retrospective data. Application of the offered simple model enables one to explain qualitatively the mechanism of VLF electromagnetic emission initiated in the process of an earthquake preparation. Besides, the model enables us to associate telluric character geoelectric and geomagnetic perturbations incited by rock polarization and self-generated electromagnetic oscillations of lithosphere-atmosphere system. L'Aquila earthquake taken as an example to isolate reliably the Earth VLF emission from the magnetospheric electromagnetic emission of the same frequency range, MHD criterion is offered together with geomagnetic activity indexes. On the basis of the considered three earthquakes, according to the opinion of authors the model of self-generated seismo-electromagnetic oscillations of the LAI system will enable us to approach the problem of resolution of earthquake prediction with certain accuracy.

scholarly journals Decrease of VLF transmitter signal and Chorus-whistler waves before l'Aquila earthquake occurrence

2010 ◽  
Vol 10 (7) ◽  
pp. 1487-1494 ◽  
Author(s):  
M. Y. Boudjada ◽  
K. Schwingenschuh ◽  
R. Döller ◽  
A. Rohznoi ◽  
M. Parrot ◽  
...  
Keyword(s):  
Seismic Event ◽  
Intensity Level ◽  
L’Aquila Earthquake ◽  
Earthquake Occurrence ◽  
The Earth ◽  
Power Spectral ◽  
Before And After ◽  
Vlf Emissions ◽  
The Magnetic Field

Abstract. We investigate the VLF emissions observed by the Instrument Champ Electrique (ICE) experiment onboard the DEMETER micro-satellite. We analyze intensity level variation 10 days before and after the occurrence of l'Aquila earthquake (EQ). We found a clear decrease of the VLF received signal related to ionospheric whistler mode (mainly Chorus emission) and to signal transmitted by the DFY VLF station in Germany, few days (more than one week) before the earthquake. The VLF power spectral density decreases of more than two orders of magnitude until the EQ, and it recovers to normal levels just after the EQ occurrence. The geomagnetic activity is principally weak four days before EQ and increases again one day before l'Aquila seismic event. Our results are discussed in the frame of short- and long-terms earthquakes prediction focusing on the crucial role of the magnetic field of the Earth.

scholarly journals The model of own seismoelectromagnetic oscillations of LAI system

2010 ◽  
Vol 2 (2) ◽  
pp. 233-250 ◽  
Author(s):  
M. K. Kachakhidze ◽  
Z. A. Kereselidze ◽  
N. K. Kachakhidze
Keyword(s):  
Low Frequency ◽  
Electrostatic Model ◽  
Charge Generation ◽  
Atmospheric Effect ◽  
Very Low Frequency ◽  
The Earth ◽  
Atmosphere System ◽  
Preparation Period ◽  
Electromagnetic Oscillations ◽  
Precursor Effects

Abstract. Very low frequency (VLF) electromagnetic radiation (in diapason 1 kHz – 1 MHz) in atmosphere, generated during earthquake preparation period, may be connected with linear size, characterizing incoming earthquake source. In order to argue this hypothesis very simple quasi-electrostatic model is used: local VLF radiation may be the manifestation of own electromagnetic oscillations of concrete seismoactive segments of lithosphere-atmosphere system. This model explains qualitatively well-known precursor effects of earthquakes. At the same time, it will be principally possible to forecast expected earthquake with certain precision if we use this model after diagnosing existed data. As physical basis of working hypothesis is atmospheric effect of polarization charges occurred in surface layer of the Earth, it is possible to test the below constructed model in medium, where reasons of polarization charge generation may be different from piezoelectric mechanism, for example, due to electrolytic hydration.

scholarly journals The model of self-generated seismo-electromagnetic oscillations of the LAI system

Solid Earth ◽  
2011 ◽  
Vol 2 (1) ◽  
pp. 17-23 ◽  
Author(s):  
M. K. Kachakhidze ◽  
Z. A. Kereselidze ◽  
N. K. Kachakhidze
Keyword(s):  
Low Frequency ◽  
Electrostatic Model ◽  
Charge Generation ◽  
Atmospheric Effect ◽  
Very Low Frequency ◽  
The Earth ◽  
Atmosphere System ◽  
Preparation Period ◽  
Electromagnetic Oscillations ◽  
Precursor Effects

Abstract. Very low frequency (VLF) electromagnetic radiation (in diapason 1 kHz–1 MHz) in the atmosphere, generated during an earthquake preparation period, may be connected with the linear size characterising the expected earthquake focus. In order to argue this hypothesis, a very simple quasi-electrostatic model is used: the local VLF radiation may represent the self-generated (own) electromagnetic oscillations of interactive seismoactive segments of the lithosphere-atmosphere system. This model qualitatively explains the well-known precursor effects of earthquakes. In addition, using this model after diagnosing existing data makes it principally possible to forecast an expected earthquake with certain precision. As a physical basis of the working hypothesis is the atmospheric effect of polarization charges occurring in the surface layer of the Earth, it is possible to test the following constructed model in the Earth's crust, where the reason for polarization charge generation may be different from piezo-electric mechanism, e.g., some other mechanism.

scholarly journals Features of the Earth surface deformations in the Kamchatka peninsula and their relation to geoacoustic emission

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 1293-1300 ◽  
Author(s):  
I. A. Larionov ◽  
Y. V. Marapulets ◽  
B. M. Shevtsov
Keyword(s):  
Michelson Interferometer ◽  
Kamchatka Peninsula ◽  
Frequency Range ◽  
Near Surface ◽  
Geoacoustic Emission ◽  
Direction Change ◽  
The Earth ◽  
Deformation Processes ◽  
Rock Deformations ◽  
Artificial Water

Abstract. The paper presents the results of investigations of deformation processes in the near-surface sedimentary rocks, which have been carried out in a seismically active region of the Kamchatka peninsula since 2007. The peculiarity of the experiments on registration of geodeformations is the application of a laser strainmeter–interferometer constructed according to the Michelson interferometer scheme. Besides rock deformations, geoacoustic emission in the frequency range from several hertz to the first tens of kilohertz is under investigation. Piezoceramic hydrophones installed in artificial water reservoirs are applied. It is shown that periods of primary rock compression and tension with a duration of up to several months are distinguished in the geodeformation process at the observation site. During the direction change in the deformations, when the geodeformation process rate grows, an increase in geoacoustic radiation is observed.

OPTICAL SYSTEM DESIGN OF THE DETECTOR FOR SOLAR TERAHERTZ EMISSION MEASUREMENTS

2021 ◽  
pp. 22-30
Author(s):  
Aleksandr A. KVASHNIN ◽  
Valery I. LOGACHEV ◽  
Maksim V. PHILIPPOV ◽  
Vladimir S. MAKHMUTOV ◽  
Osman MAKSUMOV ◽  
...  
Keyword(s):  
System Design ◽  
Optical System ◽  
Solar Flares ◽  
Electromagnetic Emission ◽  
Active Regions ◽  
Close Correlation ◽  
Frequency Range ◽  
Terahertz Emission ◽  
Optical System Design ◽  
Astrophysical Objects

The objectives and scientific tasks of the planned space experiment “Solntse-Terahertz” to be performed onboard the ISS Russian Segment are briefly described in the paper. In particular, the aim of the experiment is to study uninvestigated solar electromagnetic emission in the terahertz domain, in ~ 1012 – 1013 Hz (300-30 µm) frequency range. It is expected to obtain new data on solar active region emission including solar flare emission. These data are necessary to clarify the nature of solar activity and construct physical model of charged particle acceleration in active regions during solar flares and other astrophysical objects. We focus on the telescope optical system design and evaluation of main characteristics of this system. Results of simulations and comparison with the experimental verification of obtained characteristics are presented. A close correlation of the estimations and experimental results was obtained. As a result, main parameters of the telescope optical system of experimental hardware “Solntse-Terahertz” were determined. Key words: Sun, solar flares, terahertz emission, optical system.

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