地震研究

作为谱振幅相关分析法的拓展应用,计算了2014年10月7日云南景谷M_S6.6地震、2015年3月1日云南沧源M_S5.5地震余震序列的谱振幅相关系数。结果显示,景谷地震后谱振幅相关系数维持在高值,主震后2个月,发生了M_S5.8、5.9强余震。该高值体现出震源机制具有较高的一致性和较强的区域应力水平,有利于强余震的发生和区域中强地震丛集。沧源余震序列谱振幅相关系数的结果与景谷地震相似,一直处于高值。景谷地震与沧源地震所在地区历史地震序列以主—余型为主,不能简单地利用谱振幅相关系数的绝对值预测后续地震的大小,但两个序列的高值也许显示滇南较大区域目前正处于强应力状态下,存在发生中强地震的背景。

In order to expand the application of the method of correlation coefficient of spectral amplitude,we calculated the correlation coefficient of spectral amplitude of aftershock sequence of Jinggu M_S6.6 earthquake in 2014 and Cangyuan M_S5.5 earthquake in 2015. The results show that the correlation coefficient of spectral amplitude maintained the high value after Jinggu earthquake,and the M_S5.8 and M_S5.9 strong aftershocks occurred in two months after the main shock.This high value implied the consistency of focal mechanism and the stronger regional stress,which was beneficial to occur the strong aftershock and the regional middle-strong earthquake clustering. The correlation coefficient of spectral amplitude of the aftershock sequence of Cangyuan earthquake was high,which was similar to that of Jinggu earthquake. The historical earthquake sequence which occurred in the area of the epicenters of Jinggu and Cangyuan earthquakes were mainly shock-aftershock type. It was hard to predict the magnitude of the earthquake after main shock by the absolute value of correlation coefficient of spectral amplitude. But the high values of the two earthquake sequence may show that it was in the state of the higher value of stress and existed the background of occurring the middle-strong earthquake in the southern region of Yunnan.

引言
1 谱振幅相关分析法
2 谱振幅相关系数计算结果
3 讨论与结论

图1 孟连台记录到的2014-10-07 ML4.7地震的波形(a)及其计算得到的观测位移谱(b)<br/>Fig.1 Waveform of ML4.7 earthquake on Oct.7,2014 recorded by Menglian Station(a) and the calculated observed displacement spectral(b)

图1 孟连台记录到的2014-10-07 ML4.7地震的波形(a)及其计算得到的观测位移谱(b)
Fig.1 Waveform of ML4.7 earthquake on Oct.7,2014 recorded by Menglian Station(a) and the calculated observed displacement spectral(b)

图2 景谷地震序列MS≥5.0地震震源机制解 http://www.globalcmt.org/CMTsearch.html (a)2014-10-07 21:49:39景谷MS6.6地震;(b)2014-12-06 02:43:44景谷MS5.8地震;(c)2014-12-06 18:20:00景谷MS5.9地震
Fig.2 Maps of focal mechanism solutions of MS≥5.0 earthquakes in Jinggu earthquake sequence

图3 2014年景谷6.6级(区域a)、2015年沧源5.5级(区域b)地震序列及周围台站分布图<br/>Fig.3 Distributions of the Jinggu MS6.6 earthquake sequence in 2014(area a)and the Cangyuan MS5.5 earthquake sequence in 2015(area b)in south of Yunnan Province and the surrounding stations

图3 2014年景谷6.6级(区域a)、2015年沧源5.5级(区域b)地震序列及周围台站分布图
Fig.3 Distributions of the Jinggu MS6.6 earthquake sequence in 2014(area a)and the Cangyuan MS5.5 earthquake sequence in 2015(area b)in south of Yunnan Province and the surrounding stations

图4 2014年景谷MS6.6地震序列震级—时间图(a)及谱振幅相关系数随时间变化曲线(b)<br/>Fig.4 M-t plot of the Jinggu MS6.6 earthquake sequence(a)and curve of the correlation coefficient of spectral amplitude varied with time(b)

图4 2014年景谷MS6.6地震序列震级—时间图(a)及谱振幅相关系数随时间变化曲线(b)
Fig.4 M-t plot of the Jinggu MS6.6 earthquake sequence(a)and curve of the correlation coefficient of spectral amplitude varied with time(b)

图5 沧源MS5.5地震震源机制解 http://www.cea-ipg.ac.cn.<br/>Fig.5 Focal mechanism solution of Cangyuan MS5.5 earthquake

图5 沧源MS5.5地震震源机制解 http://www.cea-ipg.ac.cn.
Fig.5 Focal mechanism solution of Cangyuan MS5.5 earthquake

图6 2015年沧源MS5.5地震序列震级时间图(a)及谱振幅相关系数随时间变化曲线(b)<br/>Fig.6 M-t plot of the Cangyuan MS5.5 earthquake sequence(a)and curve of the correlation coefficient of spectral amplitude varied with time(b)

图6 2015年沧源MS5.5地震序列震级时间图(a)及谱振幅相关系数随时间变化曲线(b)
Fig.6 M-t plot of the Cangyuan MS5.5 earthquake sequence(a)and curve of the correlation coefficient of spectral amplitude varied with time(b)

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备注

引言

1 谱振幅相关分析法

2 谱振幅相关系数计算结果

3 讨论与结论

期刊信息