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

I El-Hussain,A Deif,Z Al-Habsi,M A Baptista,R Omira,A M E Mohamed

doi:10.1186/s40562-018-0129-4

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 source-to-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.

Highlights

In the aftermath of the 2004 Indian Ocean tsunami, tsunami science gained particular attention from the scientific community, stakeholders, and humanitarian organizations, all with the objective to protect the endangered coastal population and to mitigate the tsunami impact from future events
Some authors argue that DTHA can better serve the purpose of coastal engineering to develop tsunami mitigation measures as it allows deriving the maximum tsunami metrics for the worst scenario, avoiding the complications associated with probabilistic analysis, which requires long return periods to assess such maximum tsunami impact characteristics
The hazard is expressed in terms of maximum wave height and tsunami travel time

Summary

Introduction

In the aftermath of the 2004 Indian Ocean tsunami, tsunami science gained particular attention from the scientific community, stakeholders, and humanitarian organizations, all with the objective to protect the endangered coastal population and to mitigate the tsunami impact from future events. The deterministic, called scenario-based, approach uses a particular source scenario (maximum credible or worst-case scenario) to calculate the ensuing tsunami impact at the coastal areas of interest (Tinti and Armigliato 2003; Tinti et al 2005; Løvholt et al 2006; Lorito et al 2008; Harbitz et al 2012; Omira et al 2013). The products of this method consist of maps depicting the wave height, the coastal inundation and the flow velocity. Probabilistic analysis involves full hazard curves at each coastal point of interest, from which the probability exceedance maps can be derived for any tsunami hazard metric

Methods

Results

Conclusion