地球物理学进展 ›› 2018, Vol. 33 ›› Issue (6): 2259-2269.doi: 10.6038/pg2018CC0174

• 固体地球物理及空间物理学(大气、行星、地球动力学、重磁电及地震学、地热学) • 上一篇    下一篇

长江经济带中-东部地区地壳形变数值分析

庞亚瑾1,程惠红2,孙玉军3,5,杨少华4,*()   

  1. 1. 中国地震局第一监测中心, 天津 300180
    2. 中国科学院计算地球动力学重点实验室, 中国科学院大学, 北京 100049
    3. 中国地质科学院地质力学研究所, 北京 100081
    4. 中国地质科学院地质研究所,深地动力学重点实验室,北京 100037
    5. 中国地质科学院,北京 100037
  • 收稿日期:2018-04-26 修回日期:2018-09-07 出版日期:2018-12-20 发布日期:2019-03-03
  • 通讯作者: 杨少华 E-mail:yangshaohua09@sina.com
  • 作者简介:庞亚瑾,女,1990年生,博士,主要从事计算地球动力学方面的研究.(E-mail: pang. yajin@163.com)
  • 基金资助:
    中国地震局第一监测中心科技创新主任基金(FMC2018001);国家重点研发计划(2016YFC600504);中国地质调查局地质矿产调查评价专项项目(DD20179611)

Numerical analysis on the current crustal deformation in mid-eastern Yangtze River economic belt

PANG Ya-jin1,CHENG Hui-hong2,SUN Yu-jun3,5,YANG Shao-hua4,*()   

  1. 1. The First Monitoring and Application Center, China Earthquake Administration, Tianjin 300180, China
    2. Key Laboratory of Computational Geodynamics of Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
    3. Institute of Geomechanics, Chinese Academy of Geologecal Sciences, Beijing 100081, China
    4. Institute of Geology, CAGS, Key Laboratory of Deep-Earth Dynamics, Beijing 10037, China
    5. Chinese Academy of Geological Sciences, Beijing 100037, China
  • Received:2018-04-26 Revised:2018-09-07 Online:2018-12-20 Published:2019-03-03
  • Contact: Shao-hua YANG E-mail:yangshaohua09@sina.com

摘要:

长江经济带是具有全球影响力的内河经济带,也是我国综合实力最强最大的区域之一.长江经济带中-东部地块构造相对稳定,但仍存在一些可能造成潜在威胁的活动断裂.随着我国大陆环境监测网络工程实施,华南地区已开展了大量GPS速度场观测工作.据此,本文选取长江经济带中东部区域为主要研究对象,基于活动构造、深部地球物理和现今GPS速度场等资料,建立长江经济带地区三维有限元数值地质模型.以GPS速度观测数据为约束,计算长江经济带在现今构造驱动下的区域应变和应力场,进而分析和探讨在构造加载下长江经济带中东部现今地壳变形趋势,初步评估了区域地震危险性.研究结果初步显示该区域应变率积累量级约为10 -9/a,主要活动断层上库仑应力增加约50~200 Pa/a,说明长江经济区构造变形和应力积累过程相对微弱,处于构造相对稳定的状态.

关键词: 长江经济带中-东部, 活动断裂, 应变率, 地壳应力积累

Abstract:

The Yangtze River economic belt is an inland-river economic belt with global impact, which is one of the most powerful and comprehensive area in China. The mid-east part of the economic belt is tectonically stable, but is still distributed with active faults of potential seismic hazard. With the development of GPS networks in the mainland of China, there has been plenty of GPS observations in South China block. Therefore, we construct a high resolution 3-D FEM geodynamic model of mid-east part of Yangtze River economic belt, based on the active tectonics, geophysical observations and GPS velocities. Constrained by the GPS velocities, we calculate the strain rate and changes of crustal stress, and further comprehensively analyze the current crustal deformation,and seismic hazard in this region. Our numerical results show that the crustal strain rate is in a magnitude of 10 -9/a, and the Coulomb stress changes of the major active fault are approximately 50~200 Pa/a in the research area. The comparatively small strain rate and stress changes suggest the stable tectonic settings of the mid-east part of Yangtze River economic belt.

Key words: mid-eastern Yangtze River economic belt, active faults, strain rate, accumulation of crustal stress

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