The East Anatolian Fault System has been intensively studied over the years due to its potential to generate strong earthquakes and the high exposure of the economy and population in the region. This interest intensified even more after the strong earthquakes in the area at the beginning of February 2023, leading to a focused search for features and precursors that might suggest such an upcoming event. We analyze certain characteristics of seismicity within the East Anatolian Fault System before the earthquakes of February 6, 2023, with magnitudes Mw = 7.8 and Mw = 7.5, over the time period between 1983 and 2022. The earthquake catalog from January 1983 to September 2023, created by Turkish Bogazici University KOERI, is used. Processing of the data is performed by the ZMAP 7.1 software used in the MATLAB environment. Events with a magnitude greater than 2.5 are considered in four time periods: 1983–1992, 1993–2002, 2003–2012, and 2013–2022, totaling 29,346 events. The b-value of the magnitude-frequency distribution of earthquakes (slope of the recurrence graph) is determined; the parameter β, indicative of the increase or decrease in the rate of anomalous seismicity, and parameter Z, associated with anomalous seismic quiescence, is evaluated. A significant decrease in the value of b (from 1.07 to 0.84) is observed when comparing the two periods (2013–2017/2018–2022), indicating accumulated stress in the Earth’s crust. Furthermore, the Z parameter analysis for the period July 2021 to December 2022 shows evidence of relative seismic quiet in the examined area compared to the period from January 2020 to the end of June 2021. Those results suggest that the spatiotemporal variations of the studied seismic parameters could serve as predictors of the two very strong seismic events in the southern part of the Eastern Anatolian region of Turkey.
The fractal properties of seismicity and active faults in Balkans have been studied on the basis of data for distribution of earthquakes and active fault structures in the region. It was found that the fractal dimension of the area distribution of earthquake epicenters for the Balkans dE is 1.74, the fractal dimension of the time distribution of the b-value from the recurrence graph of earthquakes is equal to 0.97 and the fractal dimension of the spatial distribution of fault structures df is 1.66. The obtained results are the basis of the interpretation of self-similarity and self-organization of the two main geodynamic elements—the regional seismicity and the fault network of the Balkans.
This study investigates the spatiotemporal evolution and scaling characteristics of the 2025 seismic swarm in the Santorini–Amorgos region, one of the most seismically and volcanically active zonesin the Aegean arc. Using a high-resolution earthquake catalog including 1,601 events (ML≥ 2.9), we analyze variations in key statistical parameters—including b-value, fractal dimension (Dc), scaling exponent (αb), and the q-parameter—within cumulative time windows. Our findings reveal a marked decrease in b-value and simultaneous increase in Dcduring the swarm’s activation phase, consistent with an inverse energy cascade and progressive rupture. The spatial extent of the seismicswarm (L) contracts significantly before expanding during the decay phase, and vertical migration of the seismic barycenter suggests a fluid-triggered nucleation process. 3D visualizations confirm fault-aligned clustering and upward migration patterns, supporting a hybrid rupture mechanism governed by both tectonic faulting and fluid diffusion. These results provide critical insights into the complex dynamics of swarms in extensional volcanic environments and highlight the relevance of fractal and scaling analysis for short-term seismic hazard assessment.