地震地质 ›› 2014, Vol. 36 ›› Issue (3): 562-573.DOI: 10.3969/j.issn.0253-4967.2014.03.002

• 地震构造与地震活动 • 上一篇    下一篇

再议走滑断裂与地震孕育和发生条件

邓起东1, 朱艾斓2, 高翔3   

  1. 1. 中国地震局地质研究所, 活动构造与火山重点实验室, 北京 100029;
    2. 上海市地震局, 上海 200062;
    3. 浙江省第七地质大队, 杭州 310030
  • 收稿日期:2014-06-25 修回日期:2014-07-15 出版日期:2014-09-30 发布日期:2014-09-30
  • 作者简介:邓起东|男|1938年生|研究员|中国科学院院士|主要研究方向为活动构造|电话:010-62009027|E-mail:qddeng@ ies.ac.cn。

RE-EVALUATION OF SEISMOGENIC AND OCCURRENCE CONDITIONS OF LARGE EARTHQUAKES ON STRIKE-SLIP FAULTS

DENG Qi-dong1, ZHU Ai-lan2, GAO Xiang3   

  1. 1. Key Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China;
    2. Earthquake Administration of Shanghai Municipality, Shanghai 200062, China;
    3. The No.7 Geological Team of Zhejiang Province, Hangzhou 310030, China
  • Received:2014-06-25 Revised:2014-07-15 Online:2014-09-30 Published:2014-09-30

摘要:

走滑断裂是与大地震关系最紧密的活动断裂带。研究走滑断裂带上大地震是如何孕育和发生的是地震学家们极为关心的问题。构造地质学研究表明,走滑断裂是一个复杂的构造系统,反映了在剪切作用下产生的各类变形组合。文中立足于国内外不同走滑断裂带实例,对连续或不连续走滑断裂的几何学、运动学和演化过程进行了研究和总结;分析了走滑断裂的枢纽作用,发现枢纽轴部强烈挤压,形成闭锁,应力在此集中,应变在此局部化,地震在此成核和孕育。当闭锁的枢纽轴被突破时,沿走滑断裂发生失稳错动,产生突发性大位移,伴随大地震发生。而在不连续走滑断裂不同性质的阶区,则遵循其相应的应力场和破裂机制孕育和发生相应规模和类型的地震。

关键词: 走滑断裂, 枢纽作用, 变形局部化, 地震成核

Abstract:

Strike-slip fault are the active faults that are most closely related to large earthquakes. The study on how a large earthquake develops and occurs on strike-slip faults is an issue much concerned with the seismologists. As it is shown by structural geology studies, strike-slip faults are a complex tectonic system, which represents combination of various types of deformation under the shearing forces. Based on the research cases of various strike-slip fault zones both at home and abroad, this paper investigates and summarizes the geometry, kinematics and evolution processes of continuous or discontinuous strike-slip faults and analyzes the hinge role of the strike-slip faults. It is found that the hinge axis area is subject to intense compression, and the area is locked, where stress is concentrated, strain is localized, and earthquakes nucleate and develop. When the locked hinge axis is broken through, unstable sliding will occur along the strike-slip fault, producing sudden big displacement, accompanied with large earthquake. In the stepover zones of discontinuous strike-slip faults, earthquakes of corresponding size and type will develop and occur according to the relevant stress fields and rupture mechanics.

Key words: strike-slip fault, hinge role, deformation localization, earthquake nucleation

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