Tsunami Hazard Assessment for Masirah at a World Event
Dr. Issa El-Hussain, Director of the Earthquake Monitoring Center, SQU, has presented a paper on assessing tsunami hazards for the Masirah Island at a recent world conference in San Francisco. The research was carried out by a team that considered tsunami threats from two main tsunamigenic zones: the Makran Subduction Zone (MSZ) in the Oman Sea and the Andaman Sumatra Subduction Zone (ASSZ) in the Indian Ocean. The MSZ is considered as two separate segments: the East Makran Subduction Zone (EMSZ) and the West Makran Subduction Zone (WMSZ). The assessment was based on a deterministic approach.
The team examined the effects from two historic tsunamis: the 1945 tsunami due to an earthquake in the EMSZ (near field tsunami) and the 2004 Indian Ocean tsunami, due to an earthquake from ASSZ (far field tsunami
For all the selected scenarios, the team performed tsunami numerical simulations using a validated shallow water numerical model over a high-resolution digital elevation model (DEM) of Masirah Island. The maximum tsunami hazard with about 2 m wave height, 2.2 m run up, and 300 m inundation is due to the maximum probable earthquake with 8.8 magnitude from the EMSZ. The least tsunami hazard with about 0.6 m wave height, 0.2 m run up, and 80 m inundation is due to maximum probable earthquake with 6.9 magnitude from the WMSZ.
The team concluded that the 2004 Indian Ocean event posed a greater tsunami hazard on the Masirah Island coast than the Makran 1945 earthquake, due to its mega thrust. Due to the location of the tsunamigenic source with respect to the Masirah Island coast, the EMSZ dominates the tsunami hazard, while the ASSZ poses a lower level of hazard to the Island.