Please cite this article as: Kachakhidze, M.K., Kachakhidze, N.K., Kaladze, T.D., A Model of the generation of electromagnetic emissions detected prior to earthquakes, Physics and Chemistry of the Earth (2015), doi: http:// dx.

Abstract. Javakheti Highland is one of the most seismic active regions of the Caucasus. The majority of earthquakes observed throughout the region occur within this small area (φ = 40.8One can expect that exclusive seismic activity of Javakheti Highland testifies to global geophysical processes which take place throughout the Caucasus region. Based on the above-mentioned, of interest was to study variation with time of the number of earthquakes occurring in Javakheti region. We analysed some 695 relatively small earthquakes (2.5 ≤ M < 6.0) observed in Javalkheti Highland within the period of 1961-1992 with regard to large earthquakes M ≥ 6.0 of the region which occurred in the same period. It was found that each large earthquake of the Caucasus is anticipated by clear precursor in a form of an anomalous change in the number of relatively small earthquakes in Javakheti Highland.

Abstract. The subject of the research is the study of anomalous disturbances of the gradient of electric field potential of the atmosphere as possible precursors of earthquakes.In order to reveal such precursor Dusheti observatory (ϕ=42.05; λ=44.42) records of electric field potential's gradient (EFPG) of the atmosphere are considered for 41 earthquakes (M≥5.0) occurrence moments in the Caucasus region.Seasonal variations of atmospheric electric field potential gradient and inter overlapping influence of meteorological parameters upon this parameter are studied. Original method of "filtration" is devised and used in order to identify the effect of EFPG "clear" anomalies.The so-called "clear" anomalies are revealed from (−148.9 V/m) to 188.5 V/m limits and they are connected with occurrence moments of 29 earthquakes out of 41 discussed earthquakes (about 71%). "clear" anomalies manifest themselves in 11-day precursor window.Duration of anomalies is from 40 to 90 min.

At the present time rather diverse and interesting papers are published on the basis of ground-based and satellite data of earth VLF/LF and ULF electromagnetic (EM) emissions observed during earthquake preparation period. These phenomena are detectable both at laboratory and geological scale. Today in some seismic active countries of the world the network for collecting VLF/LF electromagnetic emissions generated during the process of the earthquake preparation has been organized. Permanent monitoring of frequency spectrum of earth VLF/LF electromagnetic emissions might turn out very useful with the view of prediction of large M ≥ 5 inland earthquakes. To prove the prediction capabilities of earth electromagnetic emissions authors have used avalanche-like unstable model of fault formation and an analogous model of electromagnetic contour, synthesis of which, is rather harmonious. According to the opinion of the authors EM emissions observed during earthquake preparation period are more universal and reliable than other earthquake indicators. In the presented paper, the possible methods of the large earthquake prediction are offered on the base of the European Network of Electromagnetic Radiation (INFREP) data existent before Crete earthquake with M = 5.6 (25/05/2016, 08:36:13 UTC) earthquake. Offered methods are capable of simultaneous determination of all three parameters necessary for incoming M ≥ 5 inland large earthquake prediction (magnitude, epicenter and time of occurring) with certain accuracy.

Very low frequency (VLF) electromagnetic radiation (in diapason 1 kHz &ndash; 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. <br><br> 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