Impact of potential tsunami induced by Okinawa trough earthquakes on southeastern seaboard of China

Utilizing spherical nonlinear shallow water equation this paper studies the impact of the 11 March 2011 Japan M9.0 earthquake tsunami on southeastern seaboard region of China， and calculates potential tsunamis induced by strong earthquakes in three different sections of Okinawa trough. Then the relation between wave heights and arrival times of the Japan tsunami and the simulated tsunamis is analyzed. The result indicates that the simulated Japan tsunami is consistent with local reports of Japan and the repots from 7 tide gauge stations on coastal line of southeastern China. The arrival times of the tsunamis induced by three different magnitude (M7.0, M7.5, M8.0) potential earthquakes in middle Okinawa trough would be 4 hours earlier than that of the Japan tsunami. The tsunami generated in middle Okinawa trough would take about 3 hours to reach some gauge stations on coastal line of eastern China. The wave heights at the gauge stations induced by an M7.5 earthquake tsunami in middle Okinawa trough are nearly the same as the wave height generated by the Japan M9.0 earthquake tsunami. The tsunami aroused by an M8.0 earthquake in middle Okinawa trough would produce about 0.9 m wave height at Dachen tide gauge station, and higher than 1.8 m at Kanmen station. The potential tsunami hazard caused by the earthquakes in northern Okinawa trough would mainly impact the seaboard of Yancheng, Jiangsu province, and Shanghai. Potential tsunami hazard aroused by earthquakes in southern Okinawa trough would mainly appear in northeastern seaboard of Taiwan province and southeastern seaboard of Zhejiang province. The simulation result of potential tsunami in Okinawa trough tectonic belt provides a valuable reference for earthquake and tsunami hazard mitigation and precaution in southeastern China seaboard.