Presentation, pp.1, 2024
The 6th of February 2023 Mw7.8 Kahramanmaraş earthquake initiated on a splay fault called Narli and proceeded along the East Anatolian Fault (EAF) bilaterally. The earthquake ruptured a long seismic gap of the EAF and the Amanos Fault which connects to the Cyprus Arc offshore. A total of more than 300 km rupture caused more than 50.000 deaths, so it is the deadliest event of the last century in Turkey. Our initial dynamic rupture simulations and recent studies verify that the rupture speed is faster toward northeast and slower toward southwest, as an indicator of the dynamic triggering at the NNE and static trigger to the SSW. In addition, dynamic overshoot might be the reason for very large destruction at the NNE of the junction (Pazarcık) between the Narlı Fault (NF) and the EAF. Therefore, understanding of the effect of the Narlı Splay Fault seems crucial, as nobody expected that the EAF would have been triggered dynamically by a splay fault. Hence, the question ‘could the slip distribution become less if the earthquake started on the EAF?’ arises. Therefore, we aim to understand the dynamic effects on the slip distribution of the 6th of February 2023 Kahramanmaraş earthquake by performing dynamic earthquake rupture simulations for not only the already occurred Kahramanmaraş earthquake, but also for previously possible different rupture initiation conditions by starting the earthquake on different segments of the EAF, using the Finite Element code PyLith. We first, generate realistic dynamic rupture simulations and validate with near field observational data, and then we initiate the Kahramanmaraş earthquake at the southern end of the Pütürge segment, northern part of the Erkenek segment and at Pazarcık (near the north eastern part of the Narlı-EAF junction). Our initial results demonstrate that if the earthquake initiated on the Pazarcık segment of the EAF, the rupture might have not enter into the NF. Also, higher initial stress excess might have required for the EAF initiation of the rupture which might be the reason for the splay fault triggering. Consequently, we aim to understand super-shear and sub-shear rupture velocity behavior of the EAF and dynamics of the Kahramanmaras earthquakes and stress transfer to neighboring faults which are significant in order to comprehend the potential of possible destructive earthquakes in the East Anatolian region, and generation of damage, shaking and PGA distribution scenarios.