Submarine landslide tsunami hazard assessment for the western Makran based on a deterministic approach

The Makran region, which borders southern Iran and Pakistan along the Gulf of Oman, has experienced multiple tsunamis in the last century, with some being triggered by submarine landslides. However, the role played by submarine landslides has been largely neglected in tsunami hazard assessments in the western Makran. In the present study, four different submarine landslide scenarios with volumes of 10–40 km3 are simulated on 25 locations in the western Makran, resulting in 100 different hypothetical scenarios. The results indicate that Oman’s coastline, a country in the western part of Makran subduction zone, is more vulnerable to the hazard of landslide-generated waves (maximum average of 3.1 m wave height) compared to Iran (maximum average 0.9 m height). Although Chabahar, Iran, and Muscat, Oman, two major cities in the region, experienced severe waves during some scenarios, it can be implied Muscat is more vulnerable to this kind of tsunami due to the significant gap between the maximum and average wave height for all scenarios. We further discuss that applying hypothetical worst-case scenarios can sometimes lead to an overestimation in tsunami hazard assessment. Therefore, more geological, sedimentological, and geotechnical considerations and studies are required for defining submarine landslide worst-case scenarios.