海南岛及北部湾海域海啸数值模拟与影响分析  

Numerical Simulation and Analysis of Tsunami Impacts on Hainan Island and Beibu Gulf Zone

作　　者：李智广[1,2,3] 谢顺平[1,2,3] 都金康[1,2,3] 黄洋 左天惠 郑文龙[1,2,3] 

机构地区：[1]南京大学地理与海洋科学学院,南京210046 [2]江苏省地理信息技术重点实验室,南京210046 [3]中国南海研究协同创新中心,南京210093 [4]广西地震局,南宁530022

出　　处：《地球信息科学学报》2015年第8期937-944,共8页Journal of Geo-information Science

基　　金：广西科技攻关计划项目(桂科攻12426002);国家自然科学基金项目(41371044)

摘　　要：海底地震引发的海啸灾害,对沿海国家和地区的影响是相关领域的研究热点。研究采用COMCOT海啸数值模拟模型,对可能发生在马尼拉海沟一次地震活动(Mw=9.0级)所引起的海啸过程进行了数值模拟,并研究了该海啸传播到海南岛和北部湾的过程及其特点,分析海啸波对这一地区可能造成的影响。研究发现,传播到北部湾地区的海啸波具有明显的非线性特征,海啸发生后2 h 10 min左右到达海南岛东海岸,首轮波高达2.1 m;随着湾内水深逐渐变浅,受制于海底摩阻,及海南岛的阻隔与缓冲作用,海啸到达广西壮族自治区南部沿海地区的时间,被推迟到距地震发生8 h后,海啸波高减小到0.4 m,海啸波能量大为衰减。研究结果表明,马尼拉海沟地震引发海啸,对海南岛东南部沿海影响较大,有成灾的可能性;而对广西壮族自治区南部沿海及北部湾地区的影响较弱,一般不会造成大的灾害。The impact of tsunami hazard to the coastal countries and regions is a hot topic within the field of tsunami research. One of the main reasons that cause a tsunami is submarine earthquake. Since the Manila Trench and a part of China＇s territory cover across the South China Sea, and the trench has frequent seismic activity, it becomes a potential tsunami source which may influence the south China. A hypothetical tsunami is simulated by adopting the COMCOT numerical tsunami model, to research its effects on the area of Hainan Island and Beibu Gulf. The tsunami is triggered by an earthquake in the Manila Trench, and the entire source is discretized into33 rectangular elements, which would produce an earthquake with a magnitude of Mw=9.0. The tsunami wave characteristics and its impacts on this region are analyzed with the help of records from the virtual tidal stations installed in the study area. The majority of tsunami energy is directed northward to the coast of China. The results indicate that the tsunami waves propagating to the Beibu Gulf Zone have distinct nonlinear characteristics,and spread more slowly than in the deep ocean. After 2 hours and 10 minutes when the earthquake occurs, the head wave propagates to the east coast of Hainan Island with the amplitude of 2.6 meters, which could bring great impacts or hazards to this area. However, because of sea bottom friction and the blocking of Hainan Island,it takes another six hours for the head wave to reach Beihai offshore, and the wave amplitude then is reduced to be less than 50 centimeters. The energy of tsunami undergoes a great loss, and it may have little impacts on the southern coast of Guangxi Province and the Beibu Gulf area. And yet, the additive effects of the tsunami and the tidal currents in the gulf area require further research.

关 键 词：海南岛及北部湾 数值模拟 海啸 COMCOT模型 

分 类 号：P731.25[天文地球—海洋科学]