Spatial and temporal analysis of seismicity and seismotectonic parameters in Albania region

A comprehensive analysis of b-value for the Albanian earthquakes was conducted using the instrumental earthquake catalogue of Albanian region. A total of 38,816 seismic events with magnitudes ML> 0.1 on the Richter scale were utilized. Statistical characteristics of the seismicity were examined based on b-value, as defined by the Gutenberg-Richter law. Considering the magnitude completeness (Mc-value) as 2.7, b-value was estimated as 1.09 ± 0.08 and it indicates a normal stress regime in the region. The Mc-value varies from 1.5 to 3.4, and spatial distribution of b-value ranges from 0.79 to 1.16. Higher b-values (> 1.0) were detected in the southernmost part of Albania, whereas lower b-values (< 1.0) were found in the western part, particularly within the Adriatic-Ionian fault zone and the Lushnje-Elbasan-Dibër transversal fault zone, as well as in the south-eastern Leskovik-Erseka-Korça fault zone. Regions with lower b-values correspond to areas with larger-magnitude events, while higher b-values are associated with smaller earthquakes. These findings suggest that b-values across Albania generally round 1.0, with lower values indicating moderate stress accumulation in the western region and within two other active seismic belts. The b-values less than 1.0 may signal areas of increased seismic potential. The occurrence probability of earthquakes across varying magnitudes was found to be very high (99%-100%) for seismic events with ML between 0.5 and 4.5, and lower (less than 95%) for events with ML > 5.5; it varied from 1% to 60% for events with larger ML > 6.0 for different Tr values. Recurrence periods for smaller magnitudes are relatively short (less than 1 year for magnitudes from 1.0 to 4.2), whereas for larger magnitudes (5.0 to 6.0), recurrence periods are longer, about 100 years. The Albanian region is characterized by a complex geological setting and significant seismic activity, and, thus, it can be stated that these types of analyses may be important in terms of seismotectonic evaluation and seismic hazard.