Tsunami hazard and risk zoning for Qurayyat in northeast Oman coast: Worst-case credible scenarios along the Makran Subduction Zone, Western Asia

Abstract

This paper investigates the deterministic tsunami hazard scenarios to assess the potential impact on the Qurayyat coast, northeast Oman. It assesses the maximum tsunami hazard characteristics with a focus on the zoning of tsunami hazard related to the human ability to stand within the inundation areas. Additionally, probabilities of buildings damage and small vessels loss are presented using fragility functions adapted from published studies of the 2011 Great East Japan Tsunami. Two worst-case credible tsunamigenic scenarios from Makran Subduction Zone (MSZ) were selected: 7.2Mw and 8.8Mw earthquake scenarios from western and eastern segments of the MSZ, respectively. A validated nonlinear shallow water numerical code with nested grids is used to simulate the tsunamis for each scenario over a 15 m-resolution grid for the Qurayyat region. Our results show that 8.8Mw earthquake corresponds to the maximum probable tsunami scenario posing the most severe threat. This scenario causes tsunami waves reaching 4.9 m and leads to a maximum runup height, maximum flow depth, and maximum inundation of 5.2 m, 3.8 m and 1.5 km, respectively. Furthermore, the tsunami hazard zoning for human stability suggests five hazard levels, ranging from “very low” to “very high” and the flooded buildings are classified into six damage levels, ranging from “minor” to “washed away”. The probabilities of buildings damage are high for minor and moderate damage levels. The vessels are classified based on their weight and location of motor. Obtained probabilities of vessels loss show that the outboard motor vessels would suffer greatest loss than inboard and the heavier ones.