SEISMOGEODYNAMICS OF THE CASPIAN SEA FOR 2018-2020 YEARS

Abstract

The seismogeodynamics analysis of the aquatorium of Caspian Sea in the Azerbaijani sector was conducted in 2018-2020 years.The first information about the earthquake in the Caspian Sea aquatorium dates back to 957 year and the last strong earthquake (M = 6.2) occurred on November 25, 2000, 50-60 km south of Absheron region.Analysis of the number of earthquakes and seismic energy shows that while the stability of seismic energy from 2016 to 2018 years was stable, in 2019 the seismic energy was twice as high.In 2020, an increase in the number of earthquakes and seismic energy compared to 2019 was observed.
Seismic analysis showed that the earthquakes in the North Caspian Sea (with magnitude of ≥1.0) are associated with the activation of the Makhachkala-Krasnovodsk and Absheron-Near Balkhan faults.Earthquakes with a magnitude of ≥2.0, mainly with a magnitude of ≥3.0 occurred in the center of the Caspian  Sea.The concentration of earthquakes was observed at the intersection of Agrakhan-Krasnovodsk, Makhachkala Krasnovodsk, Sangachal-Ogurchu and transverse GarabogazSafidrud faults. Analysis of the stress-strain areas of the Earth's crust showed that the values of displacement in the source are dominated by normal fault type movements.However, in the Central Caspian and oil fields (Azeri, Gunashli, Chirag) there are strike-slip movements.The compression and tension axes of the earthquakes show that the compression axes of the earthquakes are oriented in the direction of SW-NE, and the tension axes are mainly oriented in the direction of NW-SE. The stress situation in the study area varies over the years and is mainly characterized by extension stress.