地震地质 ›› 2020, Vol. 42 ›› Issue (2): 283-296.DOI: 10.3969/j.issn.0253-4967.2020.02.003

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GNSS空间大地测量技术在中国大陆活动地块划分中的应用和研究进展

郝明, 王庆良*   

  1. 中国地震局第二监测中心, 西安 710054
  • 收稿日期:2020-02-21 出版日期:2020-04-20 发布日期:2020-07-13
  • 通讯作者: * 王庆良, 男, 1963年生, 博士, 研究员, 主要从事地震动力学与地球探测技术、 地质资源与灾害地质等方面的研究, 电话: 029-85506503, E-mail:wangql63@163.com。
  • 作者简介:郝明, 男, 1982年生, 2012年于中国地震局地质研究所获固体地球物理专业博士学位, 副研究员, 主要从事地震大地测量数据处理与应用等方面的研究工作, 电话: 029-85506514, E-mail: ha_mg@163.com。
  • 基金资助:
    国家重点研发计划项目(2017YFC1500102)、 第二次青藏高原综合科学考察(2019QZKK0901)和国家自然科学基金(41874017, 41874117)共同资助

PROGRESS IN APPLICATION OF GNSS TO DIVISION OF ACTIVE TECTONIC BLOCKS IN CONTINENTAL CHINA

HAO Ming, WANG Qing-liang   

  1. The Second Monitoring and Application Center, China Earthquake Administration, Xi'an 710054, China
  • Received:2020-02-21 Online:2020-04-20 Published:2020-07-13

摘要: 中国科学家提出了“中国大陆的强震受控于活动地块运动与变形”的科学假说, 很好地解释了地震活动在空间上的分区、 分带现象。 活动地块为形成于晚新生代、 晚第四纪的强烈活动的地质构造, 地块边界带的构造活动性最为强烈。 以GNSS为代表的空间大地测量技术以其时空分辨率高、 覆盖范围广、 观测精度高等特点, 被应用于现今的地壳形变监测。 基于GNSS建立的中国大陆及周边地区高空间分辨率的地壳运动速度场图像, 清晰地揭示了中国大陆内部不同活动地块的不同运动与变形方式, 以及地块相互作用的构造边界带的强烈变形。 文中回顾了用于监测中国大陆地壳运动的GNSS观测数据来源及处理方法, 提出了中国大陆GNSS运动速度场以稳定的华南地块为区域参考框架的优势, 介绍了3种划分活动地块的方法以及检验地块是否具有刚性运动的判别方法。 结合GNSS速度场的最新研究成果, 阐述了具有刚性运动的华南、 塔里木、 鄂尔多斯、 阿拉善和东北地块现今的运动特征, 以及青藏高原、 天山和华北平原地块的非刚性变形。 在利用空间大地测量技术丰富和完善活动地块假说理论方面, 不仅需要地块内部和边界带分布密集的GNSS观测网络, 同时也要充分利用InSAR等其它空间大地测量技术, 并需加强与地震地质、 地球物理等多学科的交叉融合。 文中的系统总结, 对利用GNSS技术研究活动地块的运动变形特征和活动地块边界带强震孕育的动力学机理具有重要的参考价值。

关键词: 活动地块, GNSS, 地块划分, 刚性运动, 连续变形

Abstract: Chinese scientists proposed that large earthquakes that occurred in mainland China are controlled by the movement and deformation of active tectonic blocks. This scientific hypothesis explains zoned phenomenon of seismicity in space. The active tectonic blocks are intense active terranes formed in late Cenozoic and late Quaternary, and the tectonic activity of block boundaries is the intensest. Global Navigation Satellite System(GNSS)has advantages of high spatio-temporal resolution, broad coverage, and high accuracy, and is utilized to monitor contemporary crustal deformation. High accuracy and resolution of GNSS velocity field within mainland China and vicinities provided by previous studies clearly demonstrate that different active tectonic blocks behave as different patterns of movement and deformation, and block interaction boundaries have intense tectonic deformation. The paper firstly introduces the GPS networks operated by the Crustal Movement Observation Network of China(CMONOC)since 1999, and GNSS data processing methods, including GAMIT, BERNESE and GIPSY/OASIS, and discusses the advantages of using South China block as a regional reference frame for GNSS velocity field, then proposes three strategies of block division, F-test, quasi-accurate detection(QUAD), and clustering analysis. Furthermore, we introduce rigid and non-rigid block motions. Rigid block motion can be denoted by translation and rotation, while non-rigid block motion can be described by rigid motion and internal strain deformation. Internal strain deformation can be divided into uniform and linear strains. We also review the usage of F-test to distinguish whether the block acts as rigid deformation or not. In addition, combining with recent GNSS velocity results, we elaborate the characteristics of present movement of rigid block, such as the South China, Tarim, Ordos, Alashan, and Northeast China, and that of non-rigid block, such as the Tibetan plateau, Tian Shan, and North China plain. Especially, the Tibetan plateau and Tian Shan seem to deform continuously with significant internal deformation. In order to enrich and perfect the active tectonic block hypothesis, we should carefully design dense GNSS networks in inner blocks and block boundaries, optimize utilizing other space geodesy technologies such as InSAR, and strengthen combining study of geodesy, seismogeology and geophysics. Through systematic summary, this paper is very useful to employing GNSS to investigate characteristics of block movement and dynamics of large earthquakes happening in block interaction boundaries.

Key words: active tectonic block, GNSS, block division, rigid movement, continuous deformation

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