Method To Couple Uncertainty Effect Of Potential Source Parameters In The Seismic Tsunami Hazard Analysis

In recently years,many coastal countries and regions frequently experienced severe seismic tsunami disasters.The method of seismic tsunami hazard to estimate at specific offshore sites has been focused on by many scholars.At present,we usually choose the probabilistic estimation method based on numerical simulation to estimate the seismic tsunami hazard at specific offshore sites.As for this method,how to estimate the uncertainty of potential seismic tsunami source parameters and couple its effect is still a problem to be study.Research content in this article includes:(1)the strong earthquake hazard estimation for potential seismic source by means of the seismicity model based on generalized extreme value distribution;(2)the seismic tsunami hazard estimate method coupling potential seismic tsunami source parameter uncertainty;(3)the case study-the seismic tsunami hazard estimate at several specific offshore sites in China mainland southeastern coast and Taiwan coast are obtained,that coupled uncertainty effects of magnitude,focal depth and slide angle among the potential seismic tsunami source parameters.The main results are as follows:(1)We build the seismicity model based on generalize extreme value distributionfor the potential seismic tsunami source area-Manila trench subduction zone.Then we compared upper magnitude limit estimations based on generalized extreme value distribution and on truncated magnitude-frequency distribution.The results show that the upper magnitude limit estimation based on the former is larger than that based on the latter.(2)The seismic tsunami hazard estimate method coupling potential source parameters is discussed in four aspects: 1)the identification of seismic tsunami source area,2)the uncertainty estimate of potential seismic tsunami parameters,3)the numerical simulation of tsunami propagation and,4)the seismic tsunami hazard estimation.(3)In case study,we firstly choose the Manila trench subduction zone and the Ryukyu trench subduction zone as potential tsunami source areas;Then we estimate the uncertainty of magnitude,focal depth and slide angle among the two potential seismic tsunami source parameters;Afterwards we use the logical tree method and the Monte Carlo simulation technology to assign the potential seismic tsunami source parameters to get the parameters samples,and input them to COMCOT seismic tsunami numerical model to simulate tsunami propagation in the South China sea,the East China sea and its adjacent regions;Finally,based on the numerical simulation results,we obtain the seismic tsunami hazard estimates coupling the uncertainty of magnitude,focal depth,of slide angle,at 6 specific offshore sites in China mainland southeast offshore areas and in Taiwan south offshore areas.