The estimation of seismic hazards in Eastern Turkey and its surrounding area by statistical approaches

Abstract

Abstract In this study, a complete set of 19933 earthquake data in the depth range from 1 to 30 km from 12 December 1905 to 30 September 2022 was collected and analysed by using the Gutenberg–Richter (GR) earthquake frequency magnitude relationship approach to determine b-value and completeness magnitude (Mc). The size scaling b- and a-values for the overall catalogue were estimated as 0.82 ± 0.01 and 5.452, respectively. The Mc for the entire investigated region was estimated to be equal to 1.9. The observed low b-values were most likely related to differential crustal stress and strain produced by large faults located in the study region. It means that the region is prone to destructive and massive earth-quakes with high magnitudes. Statistical seismic hazard analysis methods including Gutenberg-Richter Law (GR) and Generalized Poisson Regression (GPR) were also used to detect earthquake occurrence intervals and recurrence periods. The results indicated that the GPR model is consistent with the GR model for intermediate-magnitude earthquakes. However, this coherence between the models is not valid for big earthquakes (Mw ≥ 7). According to the GR and GPR models, the return period of a magnitude 7 earthquake is 106.83 and 94.0347 years, respectively. The models used in the study confirm the expected and Pazarcık and Elbistan earthquakes on 6 February, 2023 because this region had not produced a magnitude 7 earthquake since 1893.