GRAVITY CHANGES BEFORE THE LUDIAN, YUNNAN, MS6.5 EARTHQUAKE OF 2014 AND THE THREE-DIMENSIONAL INVERSION RESEARCH

doi:10.3969/j.issn.0253-4967.2014.04.022

Abstract

Abstract:

Based on the 6 campaigns relative gravity observation data of the Xichang gravity survey network from 2012 to 2014, we analyze the gravity change patterns between two adjacent observation campaigns, the dynamic patterns of cumulated gravity change relative to the first campaign and the gravity time-variation at some stations near the epicenter of Ludian earthquake in the study area. We find that there was no obvious cumulative trend anomaly before the Ludian M_S6.5 earthquake 2 years ago, and the possible precursor signals are related to the gravity difference changes of the stations located at the two sides of the fault slip surface during the period of 2014-03—2014-06. Using equivalent source model to inverse these gravity anomalies, we deduce the density changes in 10^-5g/cm³ orders of magnitude to the depth of epicenter. It is inferred that the change of the mass source in the short time may be related with the filling or migration of pore fluid in the crust medium. Under the equal dynamic condition of short-time tectonic movement, fault slip in the seismogenic zone may be triggered due to fluid migration and filling, thus, resulting in generation of earthquake.

Key words: Ludian earthquake, mobile gravity observation, gravity change, equivalent source

摘要：

利用西昌测网2012—2014年6期流动重力观测资料, 分析了区域重力场差分动态变化和累积动态变化特征, 以及近震源区测点的时序变化曲线, 认为鲁甸6.5级地震前2年并没有出现明显的趋势性累积异常, 而可能的前兆信号与断层滑动面两侧的测点2014-03—2014-06时段的重力点值差异性变化相关.针对此异常采用等效源模型反演至震源深度范围内的密度值变化在10^-5g/cm³量级, 推测该质量源在短期内的变化可能与地壳内部介质孔隙流体的充填或运移相关, 在短期构造运动等动力条件下, 孕震区可能由于流体物质运移、充填并诱发断层滑动, 导致地震的发生.

关键词: 鲁甸地震, 流动重力观测, 重力变化, 等效源

CLC Number:

P315.72⁺⁶

SHI Lei, JIA Xiao-dong, CHEN Shi, XU Wei-min, LU Hong-yan. GRAVITY CHANGES BEFORE THE LUDIAN, YUNNAN, M_S6.5 EARTHQUAKE OF 2014 AND THE THREE-DIMENSIONAL INVERSION RESEARCH[J]. SEISMOLOGY AND GEOLOGY, 2014, 36(4): 1217-1227.

石磊, 贾晓东, 陈石, 徐伟民, 卢红艳. 2014年云南鲁甸6.5级地震前重力变化特征与3维反演[J]. 地震地质, 2014, 36(4): 1217-1227.

References

陈石, 王谦身, 祝意青, 等. 2011. 汶川M_S8.0震前区域重力场变化与震质中研究［J］. 地球物理学进展, 26(4): 1147—1156.
CHEN Shi, WANG Qian-shen, ZHU Yi-qing, et al. 2011. Regional gravity variation before Wenchuan M_S8.0 earthquake and epicentroid research ［J］. Progress in Geophysics, 26(4): 1147—1156(in Chinese).
陈石, 王青华, 王谦身, 等. 2014. 云南鲁甸M_S6.5地震震源区和周边三维密度结构及重力场变化［J］. 地球物理学报, 57(9): 3080—3090.
CHEN Shi, WANG Qing-hua, WANG Qian-shen, et al. 2014. The 3D density structure and gravity change of Ludian M_S6.5 Yunnan epicenter and surrounding regions ［J］. Chinese Journal of Geophysics, 57(9): 3080—3090(in Chinese).
顾功叙, 郭宗汾, 刘克人, 等. 1997. 中国京津塘张地区时间上连续的重力变化与地震的孕育和发生［J］. 科学通报, 42(18): 1920—1930.
GU Gong-xu, GUO Zong-fen, LIU Ke-ren, et al. 1997. Seismogenesis and occurrence of earthquakes as observed by temporally continuous gravity variations in China ［J］. Chinese Science Bulletin, 42(18): 1920—1930(in Chinese).
申重阳, 李辉, 孙少安, 等. 2009. 重力场动态变化与汶川M_S8.0地震孕育过程［J］. 地球物理学报, 52(10): 2547—2557.
SHEN Chong-yang, LI Hui, SUN Shao-an, et al. 2009. Dynamic variations of gravity and the preparation process of the Wenchuan M_S8.0 earthquake ［J］. Chinese Journal of Geophysics, 52(10): 2547—2557(in Chinese).
王未来, 吴建平, 房立华, 等. 2014. 2014年云南鲁甸M_S 6.5地震序列的双差定位［J］. 地球物理学报, 57(9): 3042—3051.
WANG Wei-lai, WU Jian-ping, FANG Li-hua, et al. 2014. Double difference location of the Ludian M_S6.5 earthquake sequences in Yunnan Province in 2014 ［J］. Chinese Journal of Geophysics, 57(9): 3042—3051(in Chinese).
徐锡伟, 江国焰, 于贵华, 等. 2014. 鲁甸6.5级地震发震断层判定及其构造属性讨论［J］. 地球物理学报, 57(9): 3060—3068.
XU Xi-wei, JIANG Guo-yan, YU Gui-hua, et al. 2014. Discussion on seismogenic fault of the Ludian M_S6.5 earthquake and its tectonic attribution ［J］. Chinese Journal of Geophysics, 57(9): 3060—3068(in Chinese).
祝意青, 梁伟锋, 湛飞并, 等. 2012. 中国大陆重力场动态变化研究［J］. 地球物理学报, 55(3): 804—813.
ZHU Yi-qing, Liang Wei-feng, ZHAN Fei-bing, et al. 2012. Study on dynamic of gravity field in China continent ［J］. Chinese Journal of Geophysics, 55(3): 804—813(in Chinese).
祝意青, 闻学泽, 孙和平, 等. 2013. 2013年四川芦山M_S 7.0地震前的重力变化［J］. 地球物理学报, 56(6): 1887—1894.
ZHU Yi-qing, WEN Xue-ze, SUN He-ping, et al. 2013. Gravity changes before the Lushan, Sichuan, M_S7.0 earthquake of 2013 ［J］. Chinese Journal of Geophysics, 56(6): 1887—1894(in Chinese).
祝意青, 赵云峰, 李铁明, 等. 2014. 2013年甘肃岷县漳县6.6级地震前后重力场动态变化［J］. 地震地质, 36(3): 667—676. doi: 10. 3969/j. issn. 0253-4967. 2014. 03. 010.
ZHU Yi-qing, ZHAO Yun-feng, LI Tie-ming, et al. 2014. Dynamic variation of gravity field before and after the Minxian-Zhangxian M_S6.6 earthquake on July 22, 2013, Gansu, China ［J］. Seismology and Geology, 36(3): 667—676(in Chinese).
Kuo J T, Sun Y F. 1993. Modeling gravity variations caused by dilatancies ［J］. Tectonophysics, 227(1-4): 127—143.
Li Y, Oldenburg D W. 1998. 3D inversion of gravity data ［J］. Geophysics, 60(1): 109—119.
Oldenburg D W. 1974. The inversion and interpretation of graivty anomalies ［J］. Geophysics, 39(5): 526—536.
Xu X W, Wen X Z, Zheng R Z, et al. 2003. Pattern of latest tectonic motion and its dynamics for active blocks in Sichuan-Yunan region, China ［J］. Science in China(Ser D), 46(2): 210—226.
Zhang P Z, Deng Q D, Zhang G M, et al. 2003. Active tectonic blocks and strong earthquakes in the continent of China ［J］. Science in China(Ser D), 46(Suppl 2): 1—24.

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GRAVITY CHANGES BEFORE THE LUDIAN, YUNNAN, M_S6.5 EARTHQUAKE OF 2014 AND THE THREE-DIMENSIONAL INVERSION RESEARCH

2014年云南鲁甸6.5级地震前重力变化特征与3维反演

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