琉球-马尼拉海沟的构造背景及发震能力评估  

EVALUATION OF RYUKYU-MANILA TRENCH TECTONIC BACKGROUND AND SEISMOGENIC ABILITY

作　　者：李正芳[1] 周本刚[1] 肖海波[2] LI Zheng-fang;ZHOU Ben-gang;XIAO Hai-bo(Key Laboratory of Seismic and Volcanic Hazards,Institute of Geology,China Earthquake Administration,Beijing 100029,China;POWERCHINA Beijing Engineering Corporation Limited,Beijing 100024,China)

机构地区：[1]中国地震局地质研究所,中国地震局地震与火山灾害重点实验室,北京100029 [2]中国电建集团北京勘测设计研究院有限公司,北京100024

出　　处：《地震地质》2021年第6期1381-1397,共17页Seismology and Geology

基　　金：国家重点研发计划项目(2017YFC1500401-05)资助。

摘　　要：琉球-马尼拉海沟属于西太平洋板块俯冲带,2011年3月11日日本地震的震中同样位于西太平洋板块俯冲带,前者是否与"3·11"地震具有相同的构造背景和条件,是评估琉球-马尼拉海沟是否同样具备发生9级地震潜在能力的关键因素。文中对大量资料进行了分析,对琉球-马尼拉海沟的构造背景、分段特征及最大潜在发震能力进行了评估,认为琉球海沟属于海沟-岛弧-弧后盆地俯冲构造体系,岛弧与海沟处于向E后退的状态,表现为弱耦合特征,构造上可分为6个破裂段,最大潜在地震为8.5级;马尼拉海沟受古扩张洋脊形成俯冲板块中的"板片窗"影响,长度及规模远小于目前已发生9级以上地震的俯冲带,构造上可分为6个破裂段,最大潜在地震为8.8级。综合结果分析认为,琉球-马尼拉海沟无论是在构造背景还是规模上都与日本"3·11"地震的构造样式存在较大差异。After the Fukushima nuclear accident caused by the“3·11”earthquake tsunami in Japan,whether the coastal nuclear power stations in China are liable to similar earthquake tsunami impact has been widely concerned by the whole society.According to the previous results of earthquake tsunami impact assessment conducted by professional departments on coastal nuclear power plants,China’s coastal areas do not have the conditions for the occurrence of large-scale earthquake tsunami,but in order to fully learn from the experience and lessons of the Fukushima nuclear accident caused by Japan’s“3·11”earthquake tsunami,definite conclusions have been drawn on the offshore tsunami and its impact on nuclear power plants in the early assessment work of potential tsunami impact of coastal nuclear power stations in China,combined with the structural background,historical seismic data and tsunami impact analysis.However,whether the earthquakes in the Ryukyu trench,Manila trench and other areas can generate tsunami has not been systematically considered.Therefore,in this paper,the seismogenic capacity of the Ryukyu trench and Manila trench is evaluated based on the seismotectonic background and relevant seismic source parameters.Both Ryukyu and Manila trench belong to the west Pacific plate subduction zone,while the Japan’s“3·11”earthquake is also located in the west Pacific plate subduction zone.Therefore,whether the former has the same tectonic background and conditions as the“3·11”earthquake does is the key factor to assess whether the Ryukyu trench and Manila trench have the same potential for M9 earthquake.Based on the analysis of a large number of data,this paper evaluates the tectonic background,segmentation characteristics and maximum potential earthquake generating capacity of the Ryukyu trench and the Manila trench.The Ryukyu trench and Manila trench are located in the west of the Philippine Sea plate.There are also subduction zones distributing in the east of the Philippine Sea plate from Izu-Ogasa

关 键 词：琉球海沟 马尼拉海沟 构造分段 最大潜在地震 

分 类 号：P315.2[天文地球—地震学]