|本期目录/Table of Contents|

[1]朱 杰.2014年云南鲁甸MS6.5地震震前地脉动异常*[J].地震研究,2020,43(01):64-70.
　ZHU jie.Anomalies of Microtremors Before the Yunnan Ludian MS6.5 Earthquake in 2014[J].Journal of Seismological Research,2020,43(01):64-70.
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2014年云南鲁甸MS6.5地震震前地脉动异常*(PDF/HTML)

《地震研究》[ISSN:1000-0666/CN:53-1062/P]

卷:
43
期数:
2020年01期
页码:
64-70
栏目:
出版日期:
2020-01-30

文章信息/Info

Title:
Anomalies of Microtremors Before the Yunnan Ludian MS6.5 Earthquake in 2014
作者:
朱 杰
(云南省地震局,云南 昆明 650224)
Author(s):
ZHU jie
(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)
关键词:
鲁甸地震;  地脉动;  低频波;  前兆异常;  单台法
Keywords:
the Ludian earthquake;  microtremors;  low-frequency wave;  precursor anomaly;  polarization method
分类号:
P315.72
DOI:
-
摘要:
利用2014年鲁甸MS6.5地震前10天云南数字测震台网昭通、巧家、盐津和东川台的宽频带数字资料,通过小波阈值去噪、快速傅里叶变换等方法处理数据,研究震前地脉动的异常变化特征,并通过相关系数法、单台法等,确定其异常能量来源方位,以分辨其真正来源。结果显示:①鲁甸地震前,4个台站地脉动异常变化具有一致性,分为2个阶段,第一阶段从震前112 h左右开始,分别持续58～81 h,0.1～0.14 Hz频段包络线最大值逐渐升高; 第二阶段从震前37 h左右开始,分别持续30～37 h,0.1～0.14 Hz频段幅值最大值急剧下降,下降至某一低值时发生地震,之后又快速回升。②其低频波前兆异常能量来源方位为震源区,排除台风扰动。③该地脉动异常变化能量或与震中距有关,总体呈现出由震源区向四周扩散的趋势。
Abstract:
Using the broadband digital data of the Yunnan digital seismic network Zhaotong,Qiaojia,Yanjin and Dongchuan stations about 10 days before the Ludian MS6.5 earthquake occurred on August 3,2014,this paper deals with the data by means of wavelet threshold denoising and fast Fourier transform,and studies the anomalous variation characteristics of the recorded microtremors before earthquakes,and also determines their anomalies by means of correlation coefficient method and polarization method.The variation of energy source orientation is used to distinguish the difference between the anomalous variation and the typhoon disturbance.The results show that:①The anomalous variation of microtremors at the four stations before the Ludian earthquake is consistent,and can be divided into two stages.The first stage begins about 112 hours before the earthquake,lasts 58 hours to 81 hours,and the maximum envelope value in the frequency band of 0.1～0.14 Hz gradually increases; the second stage starts about 37 hours before the earthquake,lasts 30 hours to 37 hours,and the maximum value in the frequency band of 0.1～0.14 Hz decreases sharply.Earthquakes occur when they fall to a low value and then rise rapidly.②The energy source orientation of low-frequency wave precursor anomaly is the focal area,which eliminates typhoon disturbance.③The anomalous variation energy is related to the epicenter distance,and generally shows a trend of spreading from the focal area to the surrounding area.

参考文献/References:

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备注/Memo

备注/Memo:
收稿日期:2019-02-12

更新日期/Last Update: 2020-01-30