[H-DS08] Landslides and related phenomena

[HDS08-13] On the landslides triggered by the 2023 Turkey Syria earthquake

*Gonghui Wang¹, Tolga Görüm², Hakan Tanyas³, Ning Ma⁴ (1.Disaster Prevention Research Institute, Kyoto University, 2.Department of Solid Earth Sciences, Istanbul Technical University, 3.Faculty of Geo-Information Science and Earth Observation, University of Twente, 4.Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University)

Keywords:2023 Turkey Syria earthquake, landslides, seismic motion, landsliding mechanism, aftershocks monitoring, Shear behavior

On February 6, 2023, two major earthquakes measuring Mw 7.8 and Mw 7.5 occurred in Kahramanmaraş within 9 hours. The earthquakes impacted 11 cities in Turkey, covering an area of approximately 90,000 km², and resulted in nearly 60,000 casualties, tens of thousands injured, and more than 450,000 buildings damaged or collapsed. During the earthquakes, more than 3600 landslides had also been trigged with most of them being concentrated in the northern half of the impacted area. Field survey revealed that although most of the landslides are rock falls in small scale, bedrock rotational landslides, translational slides and lateral spreads had also been triggered in huge number. In some areas, slope instability had been initiated with the occurrence of ground cracks widely distributed on the upper slopes of some giant landslides. To better understand the initiation and movement mechanisms of these landslides, we installed seismometers on different locations of the two large-scale landslides, and obtained more than 100 aftershocks. Through analyzing these seismic recordings, we examined the possible seismic response of the slopes during the main shocks. We also took soils samples from some landslides and examined their shear behaviors under different loading conditions, and then analyzed the possible initiation and movement mechanisms of these landslides. Some preliminary results will be reported in this study.