地震研究

采用云南区域测震台网资料,运用布伦模式方法测算云南地区震源参数,对盐津、腾冲和川滇交界地区3个典型的双震型地震序列震源参数进行了综合分析研究。结果表明双震型地震震源参数中,首次强震的应力降较低,可能是受震源区存在障碍体的影响,构造应力未能在首次地震中得以完整释放,再次发震其应力降值较高,表明已突破障碍体。从地震预测角度,首次地震的应力降大小,可以初步判定震区未来是否可能再次发震。

Basing on the data in Yunnan Regional Seismic Network,we calculated the source parameters of 2 533 3.0≤M_(L,S)≤6.6 earthquakes in Yunnan from 1999 to 2013 by Brune circle model method,and analyzed the source parameters of three typical double shock earthquake sequence in the junction area of Yanjin,Tengchong and Yunnan-Sichuan. The result shows that in the source parameter of double shock earthquakes,the stress drop of the first shock is lower,which indicate the tectonic stress cannot be fully released by the effects of the existence of obstacle in focal region,however,the stress drop of the second shock is much higher than the first one,which indicate the obstacle has been broken through. In the aspect of earthquake prediction,the scaling of stress drop of the first shock can be used to make a preliminary determination whether the earthquake would happen again in focal region.

引言
1 观测资料及数学处理方法
2 震例分析 2.1 2006年盐津地震
3 讨论与结论

表1 1999～2013年云南省3.0≤M(L,S)≤6.5地震震源参数取值范围<br/>Tab.1 Source parameter range of 3.0≤M(L,S)≤6.5 earthquakes in Yunnan between 1999 and 2013

表1 1999～2013年云南省3.0≤M(L,S)≤6.5地震震源参数取值范围
Tab.1 Source parameter range of 3.0≤M(L,S)≤6.5 earthquakes in Yunnan between 1999 and 2013

图1 云南地震应力降与震级的线性回归关系图<br/>Fig.1 Linear regression relationship between magnitude and stress drop in Yunnan

图1 云南地震应力降与震级的线性回归关系图
Fig.1 Linear regression relationship between magnitude and stress drop in Yunnan

表2 震级与对应的应力降值<br/>Tab.2 Relationship between magnitude and stress drop

表2 震级与对应的应力降值
Tab.2 Relationship between magnitude and stress drop

图2 应力降与震级之间的关系(a)及应力降测定的相对标准偏差分布(b)<br/>Fig.2 Relationship between stress drop and magnitude(a)and relative standard deviation determined by stress drop(b)

图2 应力降与震级之间的关系(a)及应力降测定的相对标准偏差分布(b)
Fig.2 Relationship between stress drop and magnitude(a)and relative standard deviation determined by stress drop(b)

图3 四川攀枝花地震台记录的两次盐津5.1级地震的时域波形图(a)和频域位移振幅谱(b)<br/>Fig.3 Waveform in time domain(a)and amplitude spectrum of displacement in frequency domain(b)of Yanjin M5.1 double shock earthquakes recorded by Panzhihua Station

图3 四川攀枝花地震台记录的两次盐津5.1级地震的时域波形图(a)和频域位移振幅谱(b)
Fig.3 Waveform in time domain(a)and amplitude spectrum of displacement in frequency domain(b)of Yanjin M5.1 double shock earthquakes recorded by Panzhihua Station

图4 保山地震台的两次腾冲5.2级地震的时域波形图(a)和频域位移振幅谱(b)<br/>Fig.4 Waveform in time domain(a)and amplitude spectrum of displacement in frequency domain(b)of Tenchong M5.2 double shock earthquakes recorded by Baoshan Station

图4 保山地震台的两次腾冲5.2级地震的时域波形图(a)和频域位移振幅谱(b)
Fig.4 Waveform in time domain(a)and amplitude spectrum of displacement in frequency domain(b)of Tenchong M5.2 double shock earthquakes recorded by Baoshan Station

图5 四川省乡城地震台记录的川滇交界5.1、5.9级地震时域波形图(a)和频域位移振幅谱(b)<br/>Fig.5 Waveform in time domain(a)and amplitude spectrum of displacement in frequency domain(b)of Yunnan-Sichuan junction M5.1,M5.9 double shock earthquakes recorded by Xiangcheng Station in Sichuan

图5 四川省乡城地震台记录的川滇交界5.1、5.9级地震时域波形图(a)和频域位移振幅谱(b)
Fig.5 Waveform in time domain(a)and amplitude spectrum of displacement in frequency domain(b)of Yunnan-Sichuan junction M5.1,M5.9 double shock earthquakes recorded by Xiangcheng Station in Sichuan

图6 四川省乡城地震台记录的川滇交界5.1、5.9级地震震级与应力降时序图像<br/>Fig.6 Time sequence chart of magnitude and stress drop in the junction area of Yunnan and Sichunan M5.1,M5.9 double shock earthquakes recorded by Xiangcheng Station in Sichuan

图6 四川省乡城地震台记录的川滇交界5.1、5.9级地震震级与应力降时序图像
Fig.6 Time sequence chart of magnitude and stress drop in the junction area of Yunnan and Sichunan M5.1,M5.9 double shock earthquakes recorded by Xiangcheng Station in Sichuan

图7 彝良地震震级与应力降时序图<br/>Fig.7 Time sequence chart of magnitude and stress drop of Yiliang M5.7、5.6 earthquakes in 2012

图7 彝良地震震级与应力降时序图
Fig.7 Time sequence chart of magnitude and stress drop of Yiliang M5.7、5.6 earthquakes in 2012

表3 3个震例基本情况表<br/>Tab.3 Basic information of three earthquakes used in the study

表3 3个震例基本情况表
Tab.3 Basic information of three earthquakes used in the study

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备注

引言

1 观测资料及数学处理方法

2 震例分析 2.1 2006年盐津地震

3 讨论与结论

期刊信息