Geophysical processes and biosphere: article

Аnnotation: Based on long-term observations on the Ossetian regional GNSS-network, estimates of the deformation rate and its spatial distribution in the Ossetian part of the Greater Caucasus were obtained. The primary data analysis consists in estimating the coordinates of the determined GNSS points by equating the regional network with the global solution, calculated in the world data centers. 45 GPS-stations included in the International Terrestrial Reference Frame (ITRF) are used as reference stations. The strain rate tensor was calculated using the Shen method. To interpret the geodynamic situation, information on regional seismicity obtained from the «Earthquakes of Russia» database of Federal Research Center «Geophysical Survey of the Russian Academy of Sciences» was used. The obtained results show that, in general, the Ossetian region is in the conditions of tectonic compression, against the background of which a number of features of individual structures of the region are revealed. The Main Caucasian Ridge and the deflection of the southern slope are under conditions of not only submeridional compression, but also sublatitudinal stretching, which leads to an intensive dilatant expansion of the Eastern segment of this section. The deformation regime of the northern part of the Ossetian region differs from the southern one. The northern slope of the zone of the Main Caucasian Ridge and the foothill trough, including the Vladikavkaz fault zone, are under compression conditions with moderate intensity. At the same time, the distribution of earthquake epicenters showed that the Northern Branch is currently aseismic in the central and eastern parts of the Vladikavkaz fault. This geodynamic specificity indicates a high degree of seismic potential of the Vladikavkaz fault zone.