摘要
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.
