2008年汶川M_S8.0地震前后川西含碳气体卫星高光谱特征  

Mapping emission of carbon-bearing gases from the satellite hyperspectral data in western Sichuan before and after the 2008 Wenchuan M_S8.0 earthquake

作　　者：崔月菊[1] 杜建国[1] 荆凤[1] 李新艳[2] 

机构地区：[1]中国地震局地震预测重点实验室(地震预测研究所),中国北京100036 [2]宁夏回族自治区地震局,中国银川750001

出　　处：《地震学报》2016年第3期448-457,508,共10页Acta Seismologica Sinica

基　　金：国家自然科学基金(41403099;41373059);中国地震局地震预测研究所基本科研业务费专项(2015IES0402);高分辨率对地观测系统重大专项(31-Y30B09-9001-13/15)共同资助

摘　　要：2008年汶川地震导致了大量地下含碳气体释放.本文基于卫星高光谱数据采用差值法获取了汶川地震前后川西地区含碳气体异常的时空分布特征.结果显示汶川地震前后不同含碳气体异常的时空分布特征不同.空间分布上,CH_4,CO_2和CO异常分布于震中附近且受断裂控制明显,与热红外异常特征类似;CO和CO_2异常的范围较CH_4大,CO除沿断裂带分布外,在四川盆地也大面积出现.异常出现时间上,CO_2异常最早,其次为CH_4和CO.气体来源上,CO_2和CH_4主要来源于地球内部沿断裂带释放,在地球内部还原条件下,CH_4还可由CO_2还原形成;CO异常除了沿断裂带释放和由断裂带释放的CH_4氧化生成外,还由四川盆地渗漏的CH_4氧化生成.本文结果可用于地震监测预测研究,不仅提供了新的地震前兆观测参数,还为地震热红外异常机制"地球放气温室效应"提供了科学依据,同时对地震引起的地质碳排放研究也有重要意义.Carbon-bearing gases underground strongly emitted before and after the Ms8.0 Wenchuan earthquake in 2008. This paper obtained the temporal and spatial distribution characteristics of carbon-bearing gases anomalies by usingthe differential method with the satellite hyperspectral data. The data showed that CO2, CH4 and CO anomalies occurred before and after Wenchuan earth- quake, which were spatially controlled by the faults obviously and were similar with the thermal infrared anomaly distribution. CO and COz anomalies had a larger range than CH4. CO anomaly distributed not only along the Longmen- shan fault but also in the Sichuan basin. The order of carbon-gas anomaly appearance was CO2, CH4 and CO. CO2 and CH4 gases mainly emitted from the inner earth along the Longmenshan fault, and CH4 also may be the reduction products of CO2 under the reduce condition. CO can be controlled not only by the gas emission along the fault but also by the emitted CH4 oxidation, and CO anomaly in the Sichuan basin was caused by the oxidation of CH4 which seepes from the oil and gas field. The results not only provide new monitoring parame- ters of earthquake precursor but also a scientific basis for the mechanism of thermal infrared anomaly associated with ＂earth degassing and greenhouse effect＂, and can be used in the study of earthquake prediction. At the same time, the results play an important role in the study of geological carbon- emission caused by earthquake.

关 键 词：汶川地震 卫星高光谱 气体地球化学异常 CO2 CH4 CO 

分 类 号：P315.72[天文地球—地震学]