热带海洋学报 ›› 2016, Vol. 35 ›› Issue (1): 48-60.doi: 10.11978/2015028CSTR: 32234.14.2015028

• 海洋地球物理学 • 上一篇    下一篇

马里亚纳海沟俯冲带深地震现状对马尼拉海沟俯冲带的研究启示*

赵明辉1, 贺恩远1, 3, 孙龙涛1, 徐亚2, 游庆瑜2, 郝天珧2, 杜峰1, 3, 丘学林1   

  1. 1. 中国科学院边缘海地质重点实验室, 中国科学院南海海洋研究所, 广东 广州 510301;
    2. 中国科学院油气资源研究重点实验室, 中国科学院地质与地球物理研究所, 北京 100029; 3. 中国科学院大学, 北京 100049
  • 收稿日期:2015-02-21 出版日期:2016-01-10 发布日期:2016-02-02
  • 作者简介:赵明辉(1967—), 女, 辽宁省锦州市人, 研究员, 博士, 主要从事海洋地球物理与深部结构研究。E-mail: mhzhao@scsio.ac.cn
  • 基金资助:

    国家基金重大研究计划(91428204); 中国科学院战略性先导科技专项(B类)(XDB06030202)

Research on deep seismic structures of Mariana Trench subduction zone and its inspiration for Manila Trench subduction zone

ZHAO Minghui1, HE Enyuan1, 3, SUN Longtao1, XU Ya2, YOU Qingyu2, HAO Tianyao2, DU Feng1, 3, QIU Xuelin1   

  1. 1. Key Laboratory of Marginal Sea Geology of Chinese Academy of Sciences, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;
    2. Key Laboratory of Petroleum Resource Research of Chinese Academy of Sciences, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; 3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-02-21 Online:2016-01-10 Published:2016-02-02
  • Contact: HE Enyuan. E-mail:eyhe@scsio.ac.cn
  • Supported by:

    Natural Science Foundation of China (Major program) (contract: 91428204); Strategic Priority Research Program of the Chinese Academy of Science (contract: XDB06030202)

摘要:

综述了马里亚纳海沟俯冲带二维(2D)和三维(3D)深地震探测的研究进展, 要点如下: 1)伊豆—小笠原岛弧下方玄武质火山岩的物质成分基本一致, 中地壳的速度特征与陆壳相似, 岛弧底部镁铁质到超镁铁质的壳幔过渡层(crust- mantle transition layer, CMTL)通过拆沉(delamination)等作用返回地幔, 实现由岛弧到陆壳的演化; 2)不同年龄的洋内岛弧具有不同的速度结构特征, 说明它们的地壳密度不同, 可用不同的模型来解释; 3)岛弧体系中速度结构及演化历史在时间和空间上的特征变化, 揭示了俯冲开始时洋壳和地幔的属性以及俯冲开始的原因。马尼拉海沟与马里亚纳海沟相比, 虽然地质背景不同, 但研究方法可以借鉴。今后的马尼拉海沟俯冲带探测的重点包括海底地震仪2D/3D联合探测、海底电磁探测, 以及天然地震的长期观测等。马尼拉海沟项目的实施将加深对俯冲带运行机制的认识。

关键词: 马里亚纳海沟, 俯冲带, 海底地震仪, 海底电磁仪, 马尼拉海沟

Abstract:

We review research on the two- (2D) and three-dimensional (3D) deep seismic structures of the Mariana Trench subduction zone. We find that (1) the bulk composition beneath the basaltic volcanoes is basically consistent along the Izu-Bonin Arc. The seismic velocities of the middle crust in the arc crust are similar to those in continental crust. For the arc crust evolving to normal continental crust, a process, such as delamination, is necessary for the component of lower crust interpreted as mafic to ultramafic crust-mantle transition layer (CMTL) returning to mantle; (2) the intra-oceanic arc crusts with different ages show dissimilar velocity structures, implying different density structures and crustal growth models; (3) the temporal and spatial variation of velocity structure and evolution history in the arc system reveals the features of oceanic crust and mantle at the beginning of subduction and the reasons of subduction. Although the geologic setting of the Mariana Trench is different from that of the Manila Trench subduction, the research method could be borrowed. The critical issues of research are put forward for the Manila Trench, which include: implementing 2D combined with 3D Ocean Bottom Seismometers (OBS) seismic experiments, carrying out Ocean Bottom ElectroMagnetometers (OBEM) surveys, and long-term observations on earthquakes happened near the area. The project of the Manila Trench is promising for making breakthrough in mechanism on a subduction zone.

Key words: Mariana Trench, subduction zone, Ocean Bottom Seismometers (OBS), Ocean Bottom ElectroMagnetometers (OBEM), Manila Trench.