Impact of a Series of Destructive Kahramanmaraş Earthquakes (February 6, 2023) on the Regime of Modern Crustal Movements of the Caucasian Region

Coseismic displacements and deformations of the Earth’s crust from the world’s strongest earthquakes spread to significant distances from their epicenters. Assessment of the impact of earthquakes on the characteristics of movements and deformations of the crust in remote areas is of great scientific and practical interest. The article analyzes the impact of the earthquake in Kahramanmaraş, Turkey (February 6, 2023) on movements and deformations of the crust of the Caucasus region based on time series of continuous GNSS observations. The velocities of movements in the region before and after the Kahramanmaraş earthquake were determined. The results show the appreciable (and statistically significant) impact of earthquakes on horizontal and vertical crustal movements in remote areas. The clockwise reversal of the horizontal motion velocity vectors, decrease in horizontal velocities, and, predominantly, an increase of vertical motions were confidently recorded. The general direction of horizontal motions of GNSS stations in the Caucasus agrees with the postseismic velocity vector of ANTP station, closest to the Kahramanmaraş epicentral zone, agrees with the displacement trend of the Arabian Plate. The general trends of combined of pre- and postseismic motions show the effect of mountain structures of the Lesser Caucasus counteracting the northeastern pressure of the wedge of the Arabian Plate. The results provide important information to explain the mechanisms of regional actuotectonics and the role of strong seismic events in the modern crustal movement regime of the Caucasus.