渤海海域地震海啸灾害概率性风险评估

Probabilistic tsunami hazard assessment in the Bohai Sea

渤海作为我国地震活动性最为活跃的近海,其地震海啸风险不可忽视。本文应用概率性海啸风险评估方法对渤海周边区域的海啸风险进行评估。根据历史地震目录建立了渤海区域的震级-频率关系,基于蒙特卡洛算法随机生成了一套10万年的地震目录,最终通过对地震事件的海啸数值模拟及最大波幅的统计分析给出了环渤海区域典型重现期的最大波幅分布以及重点城市的海啸波幅曲线。评估结果表明,渤海地区海啸风险主要集中在渤海湾和莱州湾周边,波幅可达到1～3 m,辽东湾地区海啸风险较低。

As the only semi-enclosed inland sea of China, the Bohai Sea has higher seismicity level and therefore is exposed to tsunami hazard. This study aimed to evaluate the tsunami hazard along the coast of the Bohai Sea by using the probabilistic method. Firstly, we established the magnitude-frequency relationship based on the historical earthquakes catalog in this area. Then, an earthquake catalog of 100 000 years was generated through the stochastic Monte Carlo simulation. At last, based on tsunami simulation of these events and the statistical results of the maximum wave amplitude catalog, the probabilistic tsunami hazard maps of specific return periods along the Bohai Sea coasts and tsunami hazard curves for important cities surrounding the Bohai Sea were plotted. The results indicated that part of the Bohai Bay and Laizhou Bay have higher tsunami hazard than Liaodong Bay, with a moderate threat level of 1-3 m.