Probabilistic and deterministic estimates of near-field tsunami hazards in northeast Oman

Abstract

Tsunamis generated along the Makran subduction zone (MSZ) threaten the Sur coast of Oman, according to deterministic and probabilistic analyses presented here. A validated shallow water numerical code simulates the sourceto-coast propagation and quantifies the coastal hazard in terms of maximum water level, flow depth, and inundation distance. The worst-case source assumed for the eastern MSZ is a thrust earthquake of Mw 8.8. This deterministic scenario produces simulated wave heights reaching 2.5 m on the Sur coast leading to limited coastal inundation extent. Because Oman adjoins the western MSZ, the probabilistic analysis includes the effect of this segment also. The probabilistic analysis shows onshore inundations exceeding 0.4 km northwest of Sur where flow depths are likely to exceed 1 m in 500 years. Probability analysis shows lesser inundation areas with probability of exceeding 1 m flow depth up to 80% in 500-year exposure time. Teletsunamis are excluded from these analyses because far-field waves of the 2004 Indian Ocean tsunami did not impact the Sur coast. Also excluded for simplicity are tsunamis generated by submarine slides within or near MSZ rupture areas. The results of this research provide essential information for coastal planning, engineering and management in terms of tsunami hazard and an essential step toward tsunami risk reductions in the northwest Indian Ocean.

Assessment of Climate Change Impacts on Sea Surface Temperatures and Sea Level Rise—The Arabian Gulf

“…This subsidence could accelerate the sea level rise impact upon the coastal cities and low-land coastal areas. The ingress of tsunami waves is more likely to enter the Gulf through the Strait of Hormuz if strong marine earthquakes occur, as the Gulf is close to the Makran Subduction Zone (MSZ) in the Sea of Oman, which is one of the structurally active geologic regions with anticipated marine earthquakes [51,52]. The impact should be most significant along Musandam Peninsula of Oman.…”

Time‐Dependent Probabilistic Tsunami Inundation Assessment Using Mode Decomposition to Assess Uncertainty for an Earthquake Scenario

“…Epistemic uncertainty is associated with incomplete knowledge and data about the earthquake process, whereas aleatory uncertainty is attributable to the random nature of earthquake occurrence and its effects (Annaka et al, 2007). In particular, many studies have evaluated epistemic uncertainties with logic trees (e.g., Bommer & Scherbaum, 2008;El-Hussain et al, 2018;Fukutani et al, 2015;Geist & Parsons, 2006;Geist & Lynett, 2014;Horspool et al, 2014;Jho et al, 2019;Mulia et al, 2020;Park & Cox, 2016;Priest et al, 2010;Selva et al, 2016;Thio et al, 2010). Specifically, earthquake occurrence scenarios, including their geometries and occurrence rates, are epistemic uncertainties that have the greatest impact on PTHA (Grezio et al, 2017); therefore, it is usually necessary to generate a large number of seismogenic faults to account for these uncertainties.…”

A Review of Tsunami Hazards in the Makran Subduction Zone

“…Aguirre-Ayerbe et al [54] developed an integrated tsunami risk assessment approach for the purpose of enhancing the tsunami risk management in Oman considering different site-specific conditions. El-Hussain et al [105] conducted a deterministic tsunami hazard assessment along the Sur coast of Oman for a worst-case scenario (M w 8.8) and a 1945-type (M w 8.1) earthquakes. Latcharote et al [106] studied deterministic tsunami hazards in Kuwait and the Persian Gulf for a range of earthquake and landslide tsunami scenarios.…”

“…They simulated all the events in the catalogs to compute maximum tsunami wave heights along the Makran coastlines and to produce different useful tsunami hazard outcomes including probabilistic tsunami heights and hazard curves (Figure 9a,b). El-Hussain et al [105] conducted a high resolution PTHA for the coastal segment of Sur, Oman using the earthquake scenario database from El-Hussain et al [115]. They presented their results in a series of local hazard maps displaying the probability of tsunami wave height/flow depth exceeding different thresholds in given exposure times of 100 and 500 years (see e.g., Figure 10).…”

“…Alternative ways to incorporate the rupture complexity in setting up tsunami scenarios could be creating synthetic stochastic slip models and or using slip distributions of other tsunamigenic events in the world. To reduce the uncertainties, more scenario-based studies (e.g., [56,105,[115][116][117]) are essential to consider the most likely sources and to describe the impacts of possible future events in the MSZ. The above-mentioned issues are major sources of uncertainties that challenge tsunami modelers to define tsunami earthquake scenarios in the Makran region.…”