Spatio-temporal changes in b-value associated with the 2023 Türkiye earthquake

b-value analysis obtained using earthquake catalogues has been associated with stress accumulation for a very long time. In this study, the spatial and temporal distribution of the b-value, also known as the frequency magnitude distribution factor, was calculated and examined before and after the February 6, 2023, Kahramanmaraş earthquakes (Mw 7.7 and Mw 7.6). For this, all earthquakes that occurred between 1900 and the earthquakes of February 6, 2023, and all aftershocks that occurred until September 1, 2023, were used. A circular area with a radius of 300 km, including nearby active faults from the center of the first earthquake to the center of the second earthquake, was divided into grids of equal size. The b-value was calculated for each grid using the maximum likelihood method. Very low b values were detected in the area where the first earthquake occurred, and it was observed that the b-value decreased relatively in the area where the second earthquake occurred. From the change in b-value over time, it was determined that the b-value has decreased significantly in recent years. This situation is associated with stress accumulation in the area where both earthquakes occurred, especially the low b values of the region where the first earthquake occurred. The fact that b values obtained using aftershocks are still low suggests that stress in the region is not completely released, has not been completely relieved and aftershocks will continue for a long time. © Indian Academy of Sciences 2024.