Triggering relationship between M7.8 and M7.5 earthquakes in Turkey on February 6,2023
At 4:17 AM local time on February 6,2023,a powerful 7.8 magnitude earthquake struck the city of Elazığ in southeastern Turkey.The earthquake originated at a depth of approximately 10 km and had a fault length of about 390 km.Roughly 9 hours later,a magnitude 7.5 earthquake occurred approximately 95 km north of the epicenter of the M7.8 earthquake,with a focal depth of 7.4 km.Both seismic events were centered on the East Anatolian Fault System and exhibited characteristics of left-lateral strike-slip faults.The relative movement of the Arabian Plate,European Plate,African Plate and Anatolia Block were identified as the primary factors leading to these earthquakes.In this study,the Coulomb stress change on the surrounding faults following the M7.8 earthquake in Turkey was computed using the finite fault slip model.By employing the Coulomb model and considering the temporal and spatial evolution of the fault,as well as the stress state of the fault,this study investigates the triggering relationship between the M7.8 earthquake and the subsequent M7.5 earthquake.Our calculations indicate that it would take approximately 1.2 to 29.6 hours,with a maximum of no more than 290.1 hours,for the Sürgü fault to undergo macroscopic instability when subjected to a static Coulomb stress increase of 0.2 MPa.Notably,the M7.5 earthquake occurred roughly 9 hours after the M7.8 earthquake,closely aligning with our calculated occurrence time.This finding highlights a strong agreement between our calculations and the actual occurrence of the M7.5 earthquake.
Turkey M7.8 earthquakeCoulomb stress changeEarthquake triggeringSpace-time evolution process
万方数据
维普
