Space–Time Stress Variations near the East Anatolian Fault Zone and the Triggering Relationship of Earthquakes

Several major earthquakes have taken place near the East Anatolian fault zone (EAFZ) in history. Despite extensive research on the Coulomb stress changes associated with these earthquakes, there remains a paucity of studies examining the spatial and temporal distribution of Coulomb stress near the East Anatolian fault zone over extended periods. This study investigates the changes in Coulomb stress induced by significant earthquakes (≥6 Mw) near the EAFZ from 1986 to 2023. High-stress changes (1.5–2.5 bar) were observed along the fault’s northeastern and southwestern segments, indicating a high likelihood of future seismicity. We also found that the three major earthquakes between 1986 and 2003 had little impact on subsequent major seismic events in the vicinity. However, the 2020 Mw 6.8 earthquake generated a Coulomb stress increment exceeding 0.1 bar, which influenced nearby seismic activity for two years. This suggests that the 2023 major earthquakes were likely facilitated by this stress change. Parameter sensitivity analysis shows fault strikes significantly affect calculations, highlighting the importance of accurate source mechanisms for reliable results. The findings of this study offer critical insights for seismologists and geophysicists aiming to refine earthquake-triggering models and stress transfer mechanisms. Civil engineers and urban planners can utilize the identified high-stress zones to prioritize seismic retrofitting of infrastructure.