MODERN SEISMOGEODYNAMICS OF THE NORTH-WESTERN PART OF AZERBAIJAN

Abstract

The article presents an analysis of the seismicity of focal zones in the northwestern part of the  Republic of Azerbaijan. Using a geodynamic model of a pair of right-lateral strike-slip faults, an interpretation of the focal mechanisms of the Zagatala, Balakan, Oghuz, Gabala and Sheki earthquakes was given, and a mechanism of the Caucasian fault with a left-sided strike-slip component was established. A connection between the observed seismicity and the tectonic structure of the region was revealed. The nature of movements in the active parts of deep faults has been revealed. An analysis of the orientation of the main stress axes of earthquake focal mechanisms was carried out. Depth profiles of displacements in the sources of strong earthquakes were constructed.
Based on the orientation data of the compression and tension axes, a map of the distribution of the Lode-Nadai coefficient was constructed. As can be seen on the maps, the Zagatala, Balakan and Gabala regions are mainly characterized by tensile stresses. Compressive stresses are observed in the Sheki and Oghuz regions. Thus, in 2003-2023, the displacement values were determined in the foci of earthquakes with magnitude ml≥4 in the Balaken, Zagatala, Sheki, Oguz and Gabala regions. In the Sheki, Oguz, Gabala regions at a depth of 12-19 km, the displacement is 0.26-0.35 m, and in the Zagatala and Balakan regions 0.15-0.27 m at a depth of 3-15 km. The smallest displacement of 0.1 0.12 m was recorded in the Sheki region.