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Quantitative probability has been computed for the tsunami hazard posed by earthquakes from the Manila Trench, which has been regarded as a huge threat in the South China Sea. This study provides a spatial distribution of the tsunami hazard covering the affected area with a spatial resolution of 0.1° for disaster prevention of islands and continental coasts. The quantitative probability of the tsunami hazard is computed by an efficient model, which can realize a large amount of potential tsunami scenarios analysis in order to consider the randomness and uncertainty in earthquake magnitude, source location and focal depth. In the model, for each potential tsunami scenario, the occurrence probability of the corresponding earthquake and the intensity of tsunami waves at each target location are computed. The occurrence probability of each scenario is estimated based on the historical earthquake records. Then, the subsequent tsunami caused by each scenario is computed using a new, efficient approach, instead of direct simulation using an ocean dynamics model. A total of 1,380,000 scenarios are computed in order to obtain a stable statistical result. Based on the results, the spatial distribution of the tsunami hazard is discussed and high-hazard regions along the coast have been identified. [ABSTRACT FROM AUTHOR]

This study focuses on the coast around the Pearl River Estuary, and assesses tsunami hazard posed by the earthquakes along the Manila Trench. A probabilistic tsunami hazard assessment (PTHA) has been conducted based on 1,380,000 potential earthquake scenarios, in order to consider the uncertainty of seismic parameters as much as possible. To achieve such a large number of scenario simulations, the tsunami at an offshore position is firstly simulated based on a superposition approach proposed in previous studies, and then the joint probability density of incident tsunami period and height at the offshore position is obtained. After that, an amplification factor is adopted to estimate nearshore tsunami height probability from the offshore position. The amplification factor is the main concern in this study. It is commonly estimated from the Green' law based on the linear wave shoaling theory, which is a simple and effective way. However, it may loss accuracy in the coast with complicate topography and tortuous shoreline. This study numerically obtained a dataset of wave amplification factors along the concerned coast, using the two-dimensional FUNWAVE-TVD model based on the Boussinesq equations. The results confirm the significance of incident wave period and height on the amplification factor, and suggest a more carefully estimation on the amplification factor should be taken into consideration. Based the newly obtained dataset of wave amplification factors, the quantified tsunami hazard probability along the concerned coast is given. •1,380,000 potential scenarios are computed to assess nearshore tsunami hazard. • Joint probability density of tsunami period and height at offshore site is given. • Effects of wave period and height on coastal amplification factor are clarified. • Tsunami hazard around the coast of the Pearl River Estuary is presented. [ABSTRACT FROM AUTHOR]