腾冲台强震前地电场线性极化特征
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摘要
分析了位于云南西南部的腾冲地震台自1986年以来的大地电场记录资料,分别针对4次远强震和中等地方震前的电场极化特征进行了分析。结果表明,在地震发生前3个月的时间内,电场极化逐渐趋于线性,而不象正常时段时数据分布比较分散。地震越强,其线性极化特征出现得越早。电场异常的方向性与震中方位有一定关系,但也与震源区的活动断裂走向有关。综合分析了异常产生的机理,认为异常可能来自震源,而震源区构造是信号传播的最佳通道。电场的震前线性极化异常具有非常典型的短临性,对未来地震方位及时间预测具有一定的参考价值。
The geoelectric data recorded at Tengchong station located in southwest Yunnan province since 1986 were analyzed.Aiming at the polarization feature of geoelectric field before 4 distant and moderate local earthquakes,the results show that the polarization of geoelectric field gradually became linear during 3 months before earthquakes,which is different from the normal times when the data were discrete.The stronger the earthquake was,the earlier the linear polarization feature occurred.The polarization direction of geoelectric field was related to the azimuth of the epicenters,while there is close connection with the striking of active faults in focal area.Synthetically analyzing the mechanism of this kind of anomalies,it is thought that the anomalous geoelectric field signals might come from the focus and the fractures in focal area might be the best channel for the fluid flowing and propagation.The preseismic linear polarization feature of geoelectric field is typically imminent,which is of some significance in location and time prediction of future earthquakes.
The geoelectric data recorded at Tengchong station located in southwest Yunnan province since 1986 were analyzed.Aiming at the polarization feature of geoelectric field before 4 distant and moderate local earthquakes,the results show that the polarization of geoelectric field gradually became linear during 3 months before earthquakes,which is different from the normal times when the data were discrete.The stronger the earthquake was,the earlier the linear polarization feature occurred.The polarization direction of geoelectric field was related to the azimuth of the epicenters,while there is close connection with the striking of active faults in focal area.Synthetically analyzing the mechanism of this kind of anomalies,it is thought that the anomalous geoelectric field signals might come from the focus and the fractures in focal area might be the best channel for the fluid flowing and propagation.The preseismic linear polarization feature of geoelectric field is typically imminent,which is of some significance in location and time prediction of future earthquakes.
引文
[1]关华平,刘桂萍.震前电磁辐射异常与地震关系研究[J].地震学报,1995,17(2):237-246.
[2]毛桐恩,席继楼,王艳琼,等.地震过程中的大地电场变化特征[J].地球物理学报,1999,42(4):519-528.
[3]Varotsos P,Lazaridou M.Latest aspects of earthquake prediction in Greece based on seismic electricsignals[J].Toctonophysics,1991,188:321-347.
[4]赵玉林,卢军,张洪魁,等.电测量在中国地震预报中的应用[J].地震地质,2001,23(2):277-285.
[5]张学民,郭学增,郭建芳.晋冀蒙交界地区强震前的电场异常[J].地震地质,2005,27(3):420-428.
[6]Wang C Y,Gang H F.Crustal structure in Tengchong volcano-geothermal area,western Yunnan,China[J].Tectonophysics,2004,380:69-87.
[7]秦嘉政,李白基,叶建庆,等.用数字记录资料测定腾冲火山区的微震参数[J].地震研究,2000,23(2):124-131.
[8]汪志亮,余素荣.谰沧-耿马7.6级地震腾冲等台地电阻率异常特征[J].地震,1989,9(2):42-47.
[9]阮爱国,赵和云.提取地震地电场异常的垂直极化方向投影法[J].地震学报,2000,22(2):171-175.
[10]毛玉平,李盛德.澜沧、耿马地震序列图像与发震构造讨论[J].西北地震学报,1991,13(1):57-62.
[11]罗娣华,叶建庆,陈敏恭,等.丽江7.0级地震的余震震源参数研究[J].地震研究,1997,20(1):83-90.
[12]刘翔,李宗兴,李忠华,等.2001年4月12日施甸震群特征[J].地震研究,2003,26(1):36-42.
[13]王运生,王士天,李渝生.丽江7.0级大震发震机制新见[J].西北地震学报,2000,22(4):442-446.
[14]张学民,郭建芳,郭学增.河北省数字地电场数据分析[J].中国地震,2006,22(1):64-75.
[2]毛桐恩,席继楼,王艳琼,等.地震过程中的大地电场变化特征[J].地球物理学报,1999,42(4):519-528.
[3]Varotsos P,Lazaridou M.Latest aspects of earthquake prediction in Greece based on seismic electricsignals[J].Toctonophysics,1991,188:321-347.
[4]赵玉林,卢军,张洪魁,等.电测量在中国地震预报中的应用[J].地震地质,2001,23(2):277-285.
[5]张学民,郭学增,郭建芳.晋冀蒙交界地区强震前的电场异常[J].地震地质,2005,27(3):420-428.
[6]Wang C Y,Gang H F.Crustal structure in Tengchong volcano-geothermal area,western Yunnan,China[J].Tectonophysics,2004,380:69-87.
[7]秦嘉政,李白基,叶建庆,等.用数字记录资料测定腾冲火山区的微震参数[J].地震研究,2000,23(2):124-131.
[8]汪志亮,余素荣.谰沧-耿马7.6级地震腾冲等台地电阻率异常特征[J].地震,1989,9(2):42-47.
[9]阮爱国,赵和云.提取地震地电场异常的垂直极化方向投影法[J].地震学报,2000,22(2):171-175.
[10]毛玉平,李盛德.澜沧、耿马地震序列图像与发震构造讨论[J].西北地震学报,1991,13(1):57-62.
[11]罗娣华,叶建庆,陈敏恭,等.丽江7.0级地震的余震震源参数研究[J].地震研究,1997,20(1):83-90.
[12]刘翔,李宗兴,李忠华,等.2001年4月12日施甸震群特征[J].地震研究,2003,26(1):36-42.
[13]王运生,王士天,李渝生.丽江7.0级大震发震机制新见[J].西北地震学报,2000,22(4):442-446.
[14]张学民,郭建芳,郭学增.河北省数字地电场数据分析[J].中国地震,2006,22(1):64-75.
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