Probabilistic Tsunami Hazard Assessment from Manila Trench to Shantou City in China

Abstract

Manila Trench is an ocean trench that lies to the west of Luzon Island in the Philippines, which has the potential to generate a significant tsunami that could affect the coastal areas around it. This paper analyzes the tsunami hazard at the southern coastline of China, and more specifically at the city of Shantou. A Monte Carlo-type probabilistic tsunami hazard assessment (PTHA) with 5000 simulation runs was conducted using the tsunami propagation model COMCOT. A wide range of earthquake magnitudes were stochastically simulated in these zones, ranging from 7.0 to 9.0 in magnitude, and the peak nearshore tsunami amplitude (PNTA), for return periods of 100, 1,000 and 10,000 years, was determined by propagation simulations to be 0.15 m, 0.65 m and 1.75 m, respectively. Inundation simulations for the case study area, which considered various scenarios of sea level rise between the present day and the year 2100, were also conducted. The results indicate the severe influence that sea level rise could have on tsunami risks, which can provide valuable information for disaster risk managers and planners on how to develop adaptation pathways not only for this city but also for other points in the southeast coastline of China.