SEISMOLOGY AND EGOLOGY ›› 2021, Vol. 43 ›› Issue (6): 1381-1397.DOI: 10.3969/j.issn.0253-4967.2021.06.003

• Research paper • Previous Articles     Next Articles


LI Zheng-fang1)(), ZHOU Ben-gang1), XIAO Hai-bo2)   

  1. 1) Key Laboratory of Seismic and Volcanic Hazards, Institute of Geology, China Earthquake Administration, Beijing 100029, China
    2) POWERCHINA Beijing Engineering Corporation Limited, Beijing 100024, China
  • Received:2020-10-26 Revised:2021-01-08 Online:2021-12-20 Published:2022-01-29


李正芳1)(), 周本刚1), 肖海波2)   

  1. 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
  • 作者简介:李正芳, 女, 1981生, 2013年于中国地震局地质研究所获构造地质学博士学位, 副研究员, 主要研究方向为发震构造识别、 潜在震源区划分及地震危险性分析, 电话: 010-62009009, E-mail:
  • 基金资助:


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-Ogasawara trench, Mariana trench to Yap Palau-Ayu trench. Since the Ryukyu trench-Manila trench subduction zones are not in the direct contact zone between the Pacific plate and the Eurasian plate, the plate tectonic setting is obviously different from the low-angle subduction zone where the Japan's March 11 earthquake locates. From the perspective of tectonic system, the Ryukyu trench belongs to the subduction tectonic system of trench-island arc-back arc basin. The island arc and trench are retreating eastward, showing the characteristics of weak coupling. The overall scale of the Manila trench is small, and affected by the “slab window” in the subduction slab formed by the ancient spreading ridge, the length of these two trench zones is much smaller than that of the subduction zones where MW≥9 earthquakes have occurred.
Based on the comprehensive analysis of the differences in trench structure, earthquake data and etc., the Ryukyu trench can be divided into 6 rupture segments, and the section of the Manila trench concerned in this study can also be divided into 6 rupture segments. At the same time, the possibility of combined rupture of the rupture segment is considered from a conservative standpoint. The rupture segments RL5 and RL6 of the Ryukyu trench, RM2 and RM3 of the Manila trench all have the possibility of combined rupture, and rupture segments RM4, RM5 and RM6 also have the possibility of combined rupture. To sum up, the comprehensive estimation result of the maximum potential earthquake in the subduction zone is magnitude 8.5 in the Ryukyu trench and magnitude 8.8 in the Manila trench.

Key words: Ryukyu Trench, Manila Trench, structural segmentation, maximum potential earthquake


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。

关键词: 琉球海沟, 马尼拉海沟, 构造分段, 最大潜在地震

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