SEISMOLOGY AND GEOLOGY ›› 2018, Vol. 40 ›› Issue (2): 299-309.DOI: 10.3969/j.issn.0253-4967.2018.02.001

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THE RELATIONSHIP BETWEEN REGIONAL SEISMIC ENERGY RELEASE AND RELATIVE MOTION BETWEEN BLOCKS ON BOTH SIDES OF YISHU FAULT ZONE

ZHU Cheng-lin1,2, GAN Wei-jun1, JIA Yuan2, LI Jie2, YIN Hai-tao2, KONG Xiang-yang2   

  1. 1 State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China;
    2 Shandong Earthquake Agency, Jinan 250014, China
  • Received:2017-10-27 Online:2018-04-20 Published:2018-06-01

沂沭断裂带两侧地区地震能量释放与块体相对运动的关系

朱成林1,2, 甘卫军1, 贾媛2, 李杰2, 殷海涛2, 孔向阳2   

  1. 1 地震动力学国家重点实验室, 中国地震局地质研究所, 北京 100029;
    2 山东省地震局, 济南 250014
  • 通讯作者: 甘卫军,男,研究员,E-mail:wjgan@gps.gov.cn
  • 作者简介:朱成林,1984年生,男,2009年于武汉大学测绘学院获大地测量学与测量工程专业工学硕士学位,工程师,主要从事形变数据分析研究工作,E-mail:zhuchenglin1985@163.com。
  • 基金资助:
    山东省2018年重点研发计划项目(2018GSF120007)、中国地震局地震科技星火计划项目(XH17019)、山东省地震局科研基金项目(JJ1605Y)与中国地震局地震行业科研专项(20150800912)共同资助

Abstract: Following the 11 March 2011 Japan MW9.0 earthquake, frequent moderate and small events occurred on the Yishu fault zone and its either side. Using continuous GPS data and a sliding block model, this work studies the relationship between the energy release of these shocks and the block relative motion of either side of the Yishu fault zone. The results show that(1)the equivalent magnitude M from released energy and the two blocks' relative motion are well correlated when earthquakes are selected in a retrieval circle(whose center is the midpoint of the Yishu fault zone)with a radius of 250~500km and using a sliding time window of 3~10 months. The best correlation coefficient between M and the two blocks' relative motion is 0.74 and the T test shows a significant linear correlation between them.(2)Spatial distribution of the correlation coefficients shows that the relative motion of the blocks on both sides affects the energy release in the area from the north part of Yishu fault zone to the Jiaodong Peninsula area and southwest Shandong-Henan border area obviously.(3)Since June 2014, the relative motion of the two blocks on both sides of the Yishu fault zone presents a wave of change, which may be an expression of the accumulation of seismic strain energy in the Yishu fault zone and its two sides. The linear relationship between the equivalent magnitude M from released energy and two blocks' relative motion V can be fitted by linear equation M=0.51*V+3.9, showing that strain energy accumulation could be released by the moderate and small earthquakes in a timely manner, which may favorable to delay the seismic risk in the study area. It also shows, on the other hand, that earthquake energy was not released so completely in the study area since the end of 2015 to 2016, which is likely associated with the Changdao earthquake swarm in 2017.

Key words: Japan MW9.0 earthquake, Yishu fault zone, active block, block model, earthquake activity, energy release

摘要: 日本MW9.0地震后沂沭断裂带及其两侧地区中小地震活动频繁。文中利用连续GPS数据和滑动块体模型研究了上述地震活动的能量释放过程与沂沭断裂带两侧块体相对运动过程的关系,为该地区的地震危险性分析提供依据。结果表明:1)沂沭断裂带周围250~500km、时间窗长为3~10月的地震总释放能量折算震级M与两侧块体相对运动呈较好的相关性,最优相关系数为0.74,T检验显示两者显著线性相关;2)两者相关性的空间分布显示两侧块体的相对运动对沂沭断裂带北部至胶东半岛地区及鲁西南—河南交界地区的地震能量释放影响明显;3)研究区总释放能量折算震级M与两侧块体的相对运动速率VM=0.51×V+3.9的线性关系,2015年底—2016年研究区存在地震能量积累现象,2017年发生的长岛震群可能与此有关。

关键词: 日本MW9.0地震, 沂沭断裂带, 块体模型, 地震活动, 能量释放

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