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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.

The method called 'phase cone' is developed in order to define the location, time of arising and velocity of the earthquakes initiating the low-speed interference stress waves. From the data of the strong earthquakes with M≥6.0 in Caucasus region during 1900-1992, the immigrators or tectonic sources of low-speed waves were revealed, interference nodes of which had initiated 19 earthquakes out of total 33. The time of arising of low-speed stress waves or periods of awaking of tectonic sources is defined. The velocities of constant initiative waves for all events were calculated. Its average value is equal to 2.97km per year.

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 (f = 40.8° – 41.8° ; l = 43.3° – 44.3°). One 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.