刘小梅^1,2,,
吴晶^1,,,
梁春涛^3,4,
钱旗伟^1,2,
杜培笑^1,2
1. 中国科学院地质与地球物理研究所岩石圈演化国家重点实验室, 北京 100029
2. 中国科学院大学, 北京 100049
3. 成都理工大学地质灾害防治与地质环境保护国家重点实验室, 成都 610059
4. 成都理工大学地球探测与信息技术教育部重点实验室, 成都 610059

基金项目: 国家重点研发计划（2017YFC1500302），国家自然科学基金（41574055，41674059），岩石圈演化国家重点实验室自主研究课题（11731210）联合资助


详细信息

作者简介: 刘小梅, 女, 1992年生, 硕士研究生, 主要从事地震精定位工作.E-mail:liuxiaomei@mail.iggcas.ac.cn

通讯作者: 吴晶, 女, 1977年生, 副研究员, 主要从事地震各向异性、断裂带结构与震源研究.E-mail:wujing_js@mail.iggcas.ac.cn

中图分类号: P315

收稿日期:2018-05-11
修回日期:2019-02-20
上线日期:2019-04-05

The latest seismicity characteristics and significance in Longmenshan Fault Zone

LIU XiaoMei^1,2,,
WU Jing^1,,,
LIANG ChunTao^3,4,
QIAN QiWei^1,2,
DU PeiXiao^1,2
1. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, China
4. Key Laboratory of Earth Exploration and Information Technology of Ministry of Education, Chengdu University of Technology, Chengdu 610059, China


More Information

Corresponding author: WU Jing,E-mail:wujing_js@mail.iggcas.ac.cn

MSC: P315

--> Received Date: 11 May 2018
Revised Date: 20 February 2019
Available Online: 05 April 2019


摘要
摘要:综合最新布设的龙门山断裂带地震空段台阵（LmsSGA）与四川省地震局固定地震台网数据，对龙门山断裂带新近一年（2016年11月21日到2017年10月28日）的23479个地震事件开展双差定位工作，共获取包括汶川地震余震和芦山地震余震在内的6111个重定位地震事件.在此基础上，分别与汶川地震和芦山地震的早期余震空间分布特征进行比较.研究发现在汶川地震发生近十年后，其余震活动依旧活跃.汶川地震现今余震活动主要分布在10~25 km的深度区间，震源深度呈现西南段较东北段偏深的特征.此外，汶川近年余震分布相比早期余震偏深，破裂带西南段的余震活动有向深部迁移的趋势.对于芦山地震，其近期余震活动较弱，余震主要分布在10~15 km的深度区间，比早期余震的分布区间偏浅.龙门山断裂带最新余震活动分布特征表明，余震活动随着时间的推移有迁移的现象.考虑到距离主震事件已分别有5~10年的流逝时间，余震迁移现象可能由以流体扩散方式为主的准静态应力机制触发.
关键词: 龙门山断裂带/
震相识别/
双差定位/
汶川地震/
芦山地震

Abstract:Combining the newly established Longmenshan Seismic Gap Array (LmsSGA) with the permanent stations from Sichuan Earthquake Administration, we carry out double-difference location for 23479 events from November 21^st, 2016 to October 28^th, 2017 in Longmenshan Fault Zone and obtain 6111 relocated events including Wenchuan aftershocks and Lushan aftershocks. Comparing with the early aftershocks of Wenchuan event, we find that the aftershocks are still active after~10 years of Wenchuan earthquake. The Wenchuan aftershocks mainly distribute between 10 to 25 km in depth, and the focal depths in the southwestern section are much deeper compared with the depths in the northeastern section. In addition, compared with the early aftershocks of Wenchuan earthquake, the distribution of the latest aftershocks is much deeper. The aftershocks migrate toward the deeper depth in the most recent years. However, the aftershocks of Lushan earthquake are relatively weak. Moreover, the depths are mainly located between 10 to 15 km, which are much shallower than the earlier aftershocks. The distribution of the latest aftershocks in Longmenshan Fault Zone shows that the aftershocks migrate in space with time. Considering that the elapse time has been 5~10 years after the two mainshocks respectively, we suggest that the aftershock migration may be triggered by quasi-static mechanism, such as fluid diffusion.
Key words:Longmenshan Fault Zone/
Phase picking/
Double-difference relocation/
Wenchuan earthquake/
Lushan earthquake



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