摘要
采用MOST海啸传播模型计算历史地震可能在中国沿海附近引发的海啸增水。历史地震的发生频次采用Poisson分布拟合,离岸海啸增水采用复合分布进行拟合。对比Poisson-Weibull分布与Poisson-Generalized Extreme Value分布的计算结果,Poisson-Lognormal分布可以更好地描述离岸海啸增水的概率分布。进一步给出中国沿海离岸地点的海啸振幅并估计了相应的重现值。结果显示,重新期为2 500a年时,广东省东北部海域、福建省西南部海域及台湾南部和东部海域的离岸海啸振幅达到50cm。所得结果可为中国沿海城市防灾减灾提供参考。
A tsunami is one of the most catastrophic natural disasters in terms of casualties and economic losses.The tsunami forecast model developed by Pacific Marine Environmental Laboratory is based on the Method of Splitting Tsunami(MOST)and simulates the three stages of tsunami:generation,propagation and coastal inundation.The tsunami forecasting system based on this model has been proven to be reliable for the prediction and/or modeling of tsunami impacts in both far and near field for more than 40 tsunamis since 1996.It has three key components:deep-ocean observations of tsunamis in real time,refining the tsunami source based on deep-ocean observations and tsunami source function in tsunami propagation database,and high-resolution inundation forecast models.In this paper,the MOST propagation model is used to simulate the potential tsunami trigged by history earthquakes that may have tsunami threat along China mainland coasts.Statistical property is analyzed for the offshore tsunami amplitudes in depth 50 m along China coasts and their long-term return value are calculated.The threshold selection method from generalized Pareto distribution validates the rationality of only studying the history earthquake with moment magnitude over 7 degrees.The Poisson distribution is used to fit the frequency of history earthquake with moment magnitude over 7 degrees,the Poisson-generalized Pareto distribution and the Poisson-lognormal distribution are used to fit the seismic moment magnitude and the offshore tsunami amplitude separately.With the assumption that the return period of March 11,2011 Japan tsunami is 500 years,we calculate the long-term return values of offshore tsunami amplitude along China coasts.If the return period is set as 1000 years,the return values of offshore tsunami amplitudes in Guangdong province northeast seas,Fujian southwest seas,Taiwan southwest seas,Zhejiang northeast seas and seas near Shanghai are above 20 cm;especially when the return period is 2500 years,the offshore tsunami amplitudes in Guangdong
作者
王南南
董胜
WANG Nan-Nan;DONG Sheng(College of Engineering,Ocean University of China,Qingdao 266100,China)
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第1期111-116,共6页
Periodical of Ocean University of China
基金
国家自然科学基金项目(51479183)资助~~
