为了促进卫星遥感气体地球化学技术在地震监测中的推广应用,本文采用卫星高光谱数据利用差值和异常指数2种方法研究了汶川和芦山地震相关的大气 CH4和 CO异常特征。数据处理结果表明,汶川地震相关的 CH4和 CO总含量异常出现在地震发生当月,沿北东向龙门山断裂带和北西向荥经—马边断裂带呈线性分布,在两条断裂带交汇部位异常幅度最大。芦山地震相关的 CH4和 CO异常受到了汶川地震的影响。芦山地震前3个月出现 CH4和 CO异常,异常幅度明显高于汶川地震,CH4异常位于震中附近呈外低内高环状分布,CO 异常沿荥经—马边断裂带呈线性分布。这些遥感地球化学异常特征表明,CH4和 CO地球化学特征时空变化可能是两次大地震和伴随的断裂构造活动引起的。
In order to promote the application of satellite-remote-sensing geochemistry in monitoring earthquake,anomalies of atmospheric total column CH4 and CO related to 2008 Wenchuan MS 8.0 and 201 3 Lushan MS7.0 earthquakes were in-vestigated.In this study,we used difference value and anomaly index methods with satellite high-spectrum data to examine the anomaly.The CH4 and CO anomalies related to Wenchuan earthquake appeared along the NE Longmenshan and NW Xingjing-Mabian faults with the maximum in the intersection of these two faults in the month when earthquake happened. The CH4 and CO anomalies related to Lushan earthquake were affected by Wenchuan earthquake.Their maximum anoma-lies occurred 3months before Lushan earthquake and were much higher than those caused by Wenchuan earthquake.CH4 anomalies appeared in the epicenter area with ringlike shape and high value core,while CO anomalies were linearly dis-tributed along the Xingjing-Mabian Fault.These features of remote-sensing geochemical anomalies indicate that spatio-temporal distribution of atmospheric CH4 and CO anomalies may be attributed to the great earthquakes and associated fault activities.