Numerical Study of Potential Extreme Tsunami Hazard in South China Sea

Abstract

In recent one decade, after two extreme tsunamis have produced devastating damage around the Indian Ocean and Pacific Ocean, it is necessary to investigate the tsunami hazard triggered by the worst case scenario in South China Sea, while the Manila Trench is becoming the most tsunami-hazardous subduction zone. In this study, the tsunami source of a new worst case scenario (Mw=9.3) is used for hazards assessment. The Okada model is taken to generate tsunami from Manila Trench based on the tsunami source parameters, while the shallow water equations are used to simulate the tsunami propagation from earthquake source to far-field region around South China Sea. The time series of surface elevation at measured locations near important cities along coasts and islands are investigated. The tsunami propagation scenarios, the arrival time, and tsunami wave distribution are obtained and analyzed for the assessment of tsunami hazard near coasts around South China Sea. Nested finer grid is used to simulate tsunami propagation to Hainan Island, Taiwan Island, and Lingding Bay for the worst case scenario. The regions with high level hazard are identified.