壤中气氡汞联测在监测汶川余震中的作用
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摘要
四川省汶川县发生8级大地震以后,在陕西省宁强县设立余震监测点,实地定时观测了余震发生与壤中气中Rn、Hg含量变化的关系,观测时间17 a。结果发现:在发震断裂上盘的壤中气中,Hg含量一般大于200 ng/m3,是下盘的1倍以上(在有地裂缝的地段,Hg异常高达560 ng/m3),而Rn含量没有明显差异。沿发震主断裂走向,距震中越近,Rn、Hg的背景含量越高。在背景地段,壤中气Hg含量高于20 ng/m3,同时伴有Rn异常,预示300 km范围、4~48 h之内、高频率、4级以上余震发生的几率高;反之则预示无余震发生。
After the 8.0 magnitude earthquake that occurred in Wenchuan County,Sichuan Province,the authors established monitoring points of aftershock in Ningqiang County,Shaanxi Province.The relationship between the aftershocks and the Rn-Hg content change in soil gas was observed on the spot and at regular intervals in 17 days.The results show that the soil gas mercury content is generally more than 200 ng /m3 in the hanging wall of the earthquake fault,the content value is two times higher than that of the footwall(In fractures along the section,mercury anomaly value can reach 560 ng/m3),but radon content value shows no distinct change.Along the strike of the seismogenic main fault,the closer it is to the epicenter,the higher the Rn,Hg background values are.If mercury content is more than 20 ng/m3 in the background section,there is Rn anomaly simultaneously,which Indicates that there might occur higher probability of aftershock with high-frequency and over 4.0 magnitude within 300 km and 4～48 hours;if things are not like that,the aftershock will not occur.
After the 8.0 magnitude earthquake that occurred in Wenchuan County,Sichuan Province,the authors established monitoring points of aftershock in Ningqiang County,Shaanxi Province.The relationship between the aftershocks and the Rn-Hg content change in soil gas was observed on the spot and at regular intervals in 17 days.The results show that the soil gas mercury content is generally more than 200 ng /m3 in the hanging wall of the earthquake fault,the content value is two times higher than that of the footwall(In fractures along the section,mercury anomaly value can reach 560 ng/m3),but radon content value shows no distinct change.Along the strike of the seismogenic main fault,the closer it is to the epicenter,the higher the Rn,Hg background values are.If mercury content is more than 20 ng/m3 in the background section,there is Rn anomaly simultaneously,which Indicates that there might occur higher probability of aftershock with high-frequency and over 4.0 magnitude within 300 km and 4～48 hours;if things are not like that,the aftershock will not occur.
引文
[1]金仰芬,伍宗华,黄宏库,等.汞量测量监测预报地震的前景[J].地震,1987,7(5):6.
[2]张炜,阎立璋,申春生,等.水文地球化学地震前兆观测与新灵敏组分的探索[J].地震,1987,7(5):58.
[3]申春生,纪辉,朱自强.测汞技术在地震监测及减灾领域的应用[J].国际地震动态,1994,24(7):10.
[4]吴少武.氡射气浓度和汞量测量技术的现状与应用[J].地球科学进展,1989,(4):16.
[5]常秋君,何跟巧,郭玉英.壤中气汞量测量方法在地震前兆观测中的应用[J].西北地震学报,1990,12(3):79.
[6]常秋君,何跟巧,郭玉英,等.断层气定点观测主要影响因素的研究[J].西北地震学报,1993,15(4):82.
[7]汪成民,李宣瑚.我国断层气测量在地震科学研究中的应用现状[J].中国地震,1991,7(2):21.
[8]申春生,魏家珍,张振勋,等.壤中气汞前兆观测及其应用前景[J].地震,1993,13(4):58.
[9]何跟巧,常秋君,宋玉兰.托来6.0级地震的预报[J].西北地震学报,1993,15(4):82.
[10]李立平.汞临震异常的前兆机理[J].地震研究,1993,16(4):359.
[11]魏家珍,申春生.首都圈地区汞测量典型震例剖析及其映震效能评价[J].地震,1994,14(3):44.
[12]王基华,王亮,孙凤民,等.断层气动态变化特征及其与地震活动的关系[J].地震,1994,14(3):58.
[13]张慧,王长岭.观测深度对断层气(氡、汞)测量的影响[J].地震,1995,15(2):150.
[14]康春丽,杜建国.汞的地球化学特征及其映震效能[J].地质地球化学,1999,27(1):79.
[15]陈万春.地震断层气监侧的现状与展望[J].四川地震,1996,20(2):56.
[16]夏浩明.对1983~1985年地震预报方法清理攻关的反思[J].地震,1987,7(5):63.
[2]张炜,阎立璋,申春生,等.水文地球化学地震前兆观测与新灵敏组分的探索[J].地震,1987,7(5):58.
[3]申春生,纪辉,朱自强.测汞技术在地震监测及减灾领域的应用[J].国际地震动态,1994,24(7):10.
[4]吴少武.氡射气浓度和汞量测量技术的现状与应用[J].地球科学进展,1989,(4):16.
[5]常秋君,何跟巧,郭玉英.壤中气汞量测量方法在地震前兆观测中的应用[J].西北地震学报,1990,12(3):79.
[6]常秋君,何跟巧,郭玉英,等.断层气定点观测主要影响因素的研究[J].西北地震学报,1993,15(4):82.
[7]汪成民,李宣瑚.我国断层气测量在地震科学研究中的应用现状[J].中国地震,1991,7(2):21.
[8]申春生,魏家珍,张振勋,等.壤中气汞前兆观测及其应用前景[J].地震,1993,13(4):58.
[9]何跟巧,常秋君,宋玉兰.托来6.0级地震的预报[J].西北地震学报,1993,15(4):82.
[10]李立平.汞临震异常的前兆机理[J].地震研究,1993,16(4):359.
[11]魏家珍,申春生.首都圈地区汞测量典型震例剖析及其映震效能评价[J].地震,1994,14(3):44.
[12]王基华,王亮,孙凤民,等.断层气动态变化特征及其与地震活动的关系[J].地震,1994,14(3):58.
[13]张慧,王长岭.观测深度对断层气(氡、汞)测量的影响[J].地震,1995,15(2):150.
[14]康春丽,杜建国.汞的地球化学特征及其映震效能[J].地质地球化学,1999,27(1):79.
[15]陈万春.地震断层气监侧的现状与展望[J].四川地震,1996,20(2):56.
[16]夏浩明.对1983~1985年地震预报方法清理攻关的反思[J].地震,1987,7(5):63.
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