Deterministic Tsunami Hazard Assessment for the Wadam As Sahil Coast, Sultanate of Oman

Abstract

The Wadam As Sahil port and facility (study area) is part of al Batinah region of northern Oman coast. This important coastal segment may be subjected to tsunami from two subduction zones in the Indian Ocean, namely Makran Subduction Zone (MSZ) and Sumatra Subduction Zone (SSZ) in the Indian Ocean. The MSZ is divided into the East Makran Subduction Zone (EMSZ) and the West Makran Subduction Zone (WMSZ) segments. The deterministic approach for tsunami hazard assessment is estimated using the scenarios of the historic events of 1945 (HMSZ), along with two scenarios featuring Mw 8.8 event in EMSZ and Mw 7.2 in WMSZ. Sumatra Subduction Zone (SSZ) poses a very low hazard to the coast of the study area due to shielding of the Indian subcontinent, therefore, it is not considered in this study. Tsunami numerical simulations are performed utilizing validated shallow water model over a high-resolution digital elevation model of the study area. A compilation of multisource elevation data from several sources was utilized to generate the digital elevation model (DEM) for the study area. The simulated maximum probable earthquake with 7.2 magnitude from the WMSZ resulted in tsunami hazard of more than 3 m wave height, about 2.8 m run up, and nearly 800 m inundation at the study area coast. The simulated maximum probable earthquake with 8.8 magnitude from the EMSZ resulted in tsunami hazard of less than 1.5 m wave height, about 2.0 m run up, and nearly 680 m inundation at the study area coast. The WMSZ Tsunamigenic source dominates the tsunami hazard due to its close proximity to the study area coast. The EMSZ poses less hazard to the study area due to orientation of the fault and it is distant from the study area coast. The last tsunami hazard is due to Makran 1945 earthquake due to its distance, strike orientation, and relative magnitude.