芦山地震(M_S7.0)前甲烷释放与大气增温异常  

Anomalies of temperature increase and methane release before Lushan earthquake (M_S7.0)

作　　者：王杰[1,2,3] 张雄[1,2,3] 潘黎黎[1,2,3] 曾佐勋[1,2,3] 

机构地区：[1]中国地质大学(武汉)地球科学学院,湖北武汉430074 [2]中国地质大学(武汉)教育部三峡库区地质灾害研究中心,湖北武汉430074 [3]华中构造力学研究中心,湖北武汉430074

出　　处：《地学前缘》2013年第6期29-35,共7页Earth Science Frontiers

基　　金：国家"985"创新平台建设项目"长江三峡库区地质灾害研究"

摘　　要：汶川地震(MS8.0)后甲烷等流体在地震中所起的作用引起国内外学者广泛关注,但是目前的观测研究中所用的数据多来源于地面或地下基站,站点分布零散,维护困难,难以开展大范围的实时监测。文中利用美国Aqua卫星红外探测器(AIRS)反演出的甲烷浓度数据,研究了芦山MS7.0级地震前龙门山地区甲烷浓度的变化与震前大气增温异常的关系。研究表明,该探测器可以观测到震前地下甲烷的释放,为地震前兆监测提供新途径;芦山地震前甲烷释放受断裂带控制明显,主要集中于龙门山断裂、荥经—马边断裂和金坪断裂及其周边;震前大气增温异常与甲烷释放关系密切。最后探讨了地下甲烷等流体的释放机理,认为甲烷等流体的释放与地震前上地壳岩石中裂隙的发育和扩展有直接关系。The effects of methane and other fluid on earthquake have widely attracted attention of the world after the Wenchuan earthquake（MS8.0）.Since most of the data used in observation and research were derived from surface or subsurface stations which are distributed scatteringly and are costly to be maintained,it is difficult to develop real-time monitoring in a large area.We studied the relationship between the variation of methane concentration and the abnormal temperature increasing of the atmosphere before the Lushan earthquake（MS7.0）in the Longmenshan area,by using the methane concentration data extracted from Atmospheric Infrared Sounder（AIRS）on NASA＇s Aqua satellite.The results show that we could find the emission of subsurface methane before earthquake from Atmospheric Infrared Sounder,which provides a new way to monitor the seismic precursor.Moreover,this research shows that the methane emission was closely related to the abnormal temperature increasing of the atmosphere before the earthquake.The methane emission anomalies were controlled by active fractures significantly.They mainly concentrated along the Longmenshan fracture zone,Xianshuihe fault,and Rongjing-Mabian fault.Finally,we discussed the mechanism of emission of methane and other fluid.It is considered that the emission of these fluids was attributed to the fracturing and fracture propagation in the upper crust in the pre-earthquake stage.

关 键 词：芦山地震 甲烷 增温异常 地震前兆 AIRS 

分 类 号：P315[天文地球—地震学]