POSSIBLE THERMAL BRIGHTNESS TEMPERATURE ANOMALIES ASSOCIATED WITH THE LUSHAN( CHINA) M7.0 EARTHQUAKE ON 20 APRIL 2013

Lushan M 7. 0 earthquake occurred in Lushan County,Ya'an City,Sichuan Province of China,on 20 April 2013,causing 196 deaths,23 people missing and more than 12 thousands of people injured. In order to analyze the possible seismic brightness temperature anomalies which might be associated with Lushan earthquake,daily brightness temperature data are collected from Chinese geostationary meteorological satellite FY-2E,for the period from 20 April 2011 to 19 April 2013 and the geographical extent of 25° ~ 35° N latitude and 98° ~ 108° E longitude. Continuous wavelet transform method is used to analyze the power spectrum of brightness temperature data,for its good resolution both in time and frequency domains. The results show that relative wavelet power spectrum( RWPS) anomalies appeared since 15 January 2013 and still lasted on 19 April. Anomalies firstly appeared at the middle part of Longmenshan Fault zone. Then, they gradually spread towards southwestern part of Longmenshan Fault. Anomalies also appeared along the Xianshuihe Fault since about 1 March. Eventually, anomalies gathered at the intersection zone of Longmenshan and Xianshuihe Faults. The anomalous area and RWPS amplitude increased since the appearance of anomalies and reached maximum in late March. Anomalies attenuated with earthquake approaching,and eventually the earthquake occurred at the southeastern edge of anomalous area. Lushan earthquake was the only obvious geological event within the anomalous area during the time period,so the anomalous changes of RWPS are possibly associated to the earthquake.