Abstract:
An analysis of the seismicity of the Anatolian plate (Turkey) was performed based on the earthquake catalog (375951 events for 1900-2023) in connection with the earthquakes of February 6, 2023. A graph of earthquake recurrence and Gutenberg-Richter distribution were constructed and a representative part of the earthquake catalog was determined. The representative sample includes events with $M \geq 2.5$. Some statistical characteristics of the catalog have been determined. Seismic events have a depth of 0-170 km. The main part of the events occurs at a depth of 0-40 km. Deep-focus events are characteristic of extreme western and coastal southwestern Turkey. The dependence of the number of earthquakes on time was plotted for the western (up to 35$^\circ$; E) and eastern (after 35$^\circ$;E) parts of Turkey for the period 1900-2022. An increase in seismicity has been noted in the eastern part of Turkey since at the end of the 90s. Maps of the distribution of the number of events per year were constructed before (1900-2022) and after the earthquake on February 6, 2023 (January-July 2023). An active aftershock process and increased seismicity are observed throughout the East Anatolian fault zone. The value of the Tsallis parameter was calculated for the entire catalog (q=1.52). Maps of the distribution of the Tsallis parameter were constructed before (data from 1900-2022) and after the earthquake (data from January-July 2023). Until February 2023, in the zone of future earthquakes, the Tsallis parameter is q=1.44, after the earthquake on February 6, q=1.596. An increase in the Tsallis parameter indicates an active release of stress in this zone. As a characteristic of the released energy after the earthquake of February 6, 2023, the intensity of seismotectonic deformations (STD) was used and a STD intensity map was constructed. In the focal area, the STD intensity is $10^{5}$ year$^{-1}$.
Citation:
N. A. Sycheva, “Seismicity of the anatolian plate (Turkey) and earthquakes of February 6, 2023”, Vestnik KRAUNC. Fiz.-Mat. Nauki, 45:4 (2023), 122–146