PROBABILISTIC RISK ASSESSMENT OF SUBMARINE LANDSLIDE TSUNAMIS IN THE MARMARA SEA

Abstract

 Submarine landslides contain numerous uncertainties, such as their occurrence locations and the shape of the collapsed mass. Therefore, a probabilistic approach is necessary for tsunami risk assessment. This study aims to evaluate landslide tsunami hazards in the Marmara Sea. Specifically, following the method of Nagai et al. (2022) conducted for Palu, we generated 100 cases of landslide tsunami source models and calculated tsunami propagation. The landslide locations were set at the positions of traces. Next, following the method of Fukutani et al. (2021), we smoothed the empirical distribution functions obtained from the numerical calculation results. As a result, for example, a tsunami of 6 meters generated by submarine landslides in the year 1509 had an estimated return period of about 700 years. Additionally, due to the distinctive geomorphological conditions of the Sea of Marmara, spatial variations were observed in wave heights at coastal locations.