CHANGES IN COULOMB STRESSES AFTER STRONG EARTHQUAKES OCCURRED IN THE TERRITORY OF THE GREATER CAUCASUS FOR THE PERIOD 2012-2021

Abstract

The article examines the seismotectonic position of a strong earthquake that occurred on the territory of the Azerbaijan part of the Greater Caucasus for the period 2012-2021. In Bali, the focal mechanisms of strong earthquakes were analyzed: Zagatala on May 7, 2012 with Мl=5.6, 5.7, Balakan on October 14, 2012 with Мl=5.8,; Ismayilli 07.10.2012, 2019, 2021 with Ml=5.1-5.3; Gabala series on September 29 and October 4, 2014 with Мl=5.5; as well as Okhuz on 09/04/2015. The analysis showed that as a result of dynamic stresses in the Zakatal-Gabala and Balakan-Okhuz-Ismayilli regions, in the first case, initiated seismicity was observed, and in the second - no. Based on this, an assumption arose that the faults on which initiated earthquakes occur must be in a subcritical, metastable state. It was found that the spatial position of the earthquake epicenters (aftershock field) that occurred from 2012 to 2021 correlates with the zones of positive increments of critical Coulomb stresses. Their occurrence, apparently, is
associated with the accumulation of tectonic stresses of sublatitudinal extension and the localization of static stresses initiated by the Zakatala earthquakes of 2012, which together led to the emergence of instability and shear movements along the fault