2010年智利和2011年日本地震海啸在我国东南沿岸诱导的波流特征及危险性分析

Characteristics and risk assessment of tsunami-induced currents in the southeast coast of China caused from the Chile Earthquake in 2010 and Japan Earthquake in 2011

本文基于有限断层模型和OKADA位错模型计算海表变形场作为初始条件,利用MOST海啸数值模型模拟分析了2010年智利和2011年日本地震海啸在我国东南沿海地区的海啸传播特征,海啸波模拟结果与观测数据吻合较好。重点研究分析了沈家门港口海域的海啸波流特征及其诱导的涡旋结构。研究结果表明:尽管两次事件的海啸源位置及破裂特征完全不同,但海啸波流在我国东南沿岸的分布特征大致相似;另外相对于海啸波幅而言,港湾中海啸流具有更强的空间差异性,港口入口、岬角地形处和岛屿间水道中往往会有强流存在。尽管这两次越洋海啸均未能在我国东南沿海引发淹没情形,但通过数值计算发现局部均存在超过3 m/s以上的强流,因此进行海啸预警及风险管理时应综合考虑海啸波流的影响。

In this paper, based on the finite fault model and the OKADA dislocation model, we calculated the sea surface deformation as the initial condition and used the Method of Splitting Tsunami（MOST） to analyze the 2010 Chile Earthquake and 2011 Japan Earthquake induced tsunami propagation characteristics on the southeast coast of China. The results of simulation are in good agreement with the observations. This research focused on the analysis of tsunami waves and currents characteristics and vortex structure induced by tsunami in Shenjiamen port. The results show although the location and rupture characteristics of the two tsunami sources are quite different, the distributions of tsunami waves and currents are approximately similar. In addition, relative to the tsunami waves, currents have much greater spatial diversity in port. It will be stronger flow in the harbor entrance, headland and inter island waterway. Although two transoceanic tsunami disasters did not cause inundation along China＇s southeast coast, there are stronger currents over 3 m/s in the local regions by using numerical calculation. So it should take into account the impact of tsunami waves and currents on tsunami warning and risk management.