Satellite observation of CH4 and CO anomalies associated with the Wenchuan MS 8.0 and Lushan MS 7.0 earthquakes, in China


Spatial and temporal variations of total column of CH4 and CO (TotCH4 and TotCO) associated with the 12 May 2008 Wenchuan and 20 April 2013 Lushan earthquakes in western Sichuan, China were investigated using satellite data from AQUA AIRS in order to understand the lithospheric and atmospheric interactions during the seismic activity. The Wenchuan MS 8.0 and Lushan MS 7.0 earthquakes occurred in the Longmenshan fault zone. It was observed that large amounts of gases released from the earth’s crust into the atmosphere in the duration of the earthquake activities. The anomalies of TotCH4 and TotCO occurred along the fault zone with the peak values occurred at the intersection areas where the crust stress approached the maximum. Furthermore, temporal anomalies of TotCH4 and TotCO occurred during and after Wenchuan earthquake while 3 months before Lushan earthquake. The anomalies related to Lushan earthquake could be attributed to seismic activation of both the Lushan and Wenchuan earthquakes because of the seismotectonic changes and fractures in the crust produced by the Wenchuan earthquake.

Keywords: methane, carbon monoxide, earthquake, hyper-spectrum, anomaly