Structural analysis of Azerbaijan territory horizontal velocity movement based on GPS-measurements

Abstract

The contemporary kinematics of Azerbaijan is generated by the northward movement of Arabian plate relative to Eurasian one. This continuous «intervention» of Arabian plate into Eurasian one is the reason of the deformation of the Earth’s crust of the Caucasian block causing earthquakes which are registered throughout the territory. For the research of geodynamic processes and intraplate deformations it is applied the methods of global positioning (GPS). GPS-network in Azerbaijan was founded in 1998. For the period between 1998 and 2016, in many GPS-points, the measurements were done 3―6 times. The present paper deals with the research of structure distribution of GPS horizontal velocity field of intraplate zones (domains) for Azerbaijan. The comparative analysis of interrelation of seismic events with distribution of horizontal velocity vectors and deformation obtained from Azerbaijan GPS-network monitoring was done aiming to reveal those zones. Deformation distribution throughout the research area was calculated with the formula and approach of Shen with the use of horizontal components of GPS-velocities. Aiming to conduct the comparative analysis of GPS-velocities with seismicity, a map of distribution of earthquake numbers for Azerbaijan during the period of 2003―2017 with magnitude M ≥ 3 was utilized. As a result, the following domain zones were defined, such as the fold system of the Greater Caucasus, the fold system of the Lesser Caucasus, the Middle Kur, Talysh, Gusar-Shabran depression and Gobustan-Absheron zone. It was determined that the areas of high seismicity were located in the zones of high gradients of GPS-velocities, while the areas of high seismicity coincide predominantly with the areas of high velocity compression. However, Gobustan-Absheron zone with high velocity deformation is not characterized by high seismicity. Probably, the reason of this is due to the elasticity of geological environment.