OLR anomalies for the Lushan M_S7.0 earthquake

Based on the outgoing long-wave radiation data of geostationary satellite, the relative variance rate of power spectrum estimation is applied to analytical study of OLR for the Lushan M_S7.0 earthquake on 20 April 2013. The results indicate that the power spectrum anomalies of OLR arose significantly before the Lushan earthquake. The earthquake happened in the edge of the power spectrum enhancement areas.On short-impending period of the earthquake, power spectrum amplitude of OLR reached relative maximum in recent years, being eight times as large as average values. The duration of power spectrum amplitude (viz. relative change rate more than twice of average) was about 65 days. The extreme areas for power spectrum enhancement amplitude (viz. relative change rate more than 6 times) reached 120 thousand square kilometers. The short-impending anomaly distribution of this earthquake is basically consistent with the previous results of M_S≥6.5 earthquakes in Chinese mainland. The characteristics of observed thermal-radiating anomalies are easy to be recognized, and the outgoing long-wave radiation data can be updated in real time. Therefore, it is able to be used to monitor the key earthquake hazardous areas, specially the frequent strong earthquake zone with the worse seismic-monitoring capability.