Abstract:Remote sensing of rock mechanics has been used to determine that temperature changes in rocks are related to changes in rock volume.During elastic deformation,compression （expansion） of volume causes an increase （decrease） in temperature.Therefore,research of temperature abnormalities on the surface prior to earthquakes should consider areas of ground deformation by earthquakes.Qaidam block is closely connected to earthquakes such as the July 22,2013,Minxian MS6.6 earthquake in Gansu province,and Global Positioning System （GPS） data indicate that the middle and eastern parts of Qaidam block underwent compression.Therefore,research of the anomalous increase in infrared radiation by remote sensing prior to the earthquake should include data of infrared levels in the middle and eastern parts of Qaidam block.In the present study,infrared abnormalities are determined by remote sensing in the middle and eastern parts of Qaidam block prior to the July 22,2013,Minxian MS6.6 earthquake.On the basis of Moderate Resolution Imaging Spectroradiometer （MODIS） data of infrared bright temperature determined through remote sensing,we analyzed lowfrequency information of average bright temperature extracted from wavelet decomposition in the middle and eastern parts of Qaidam block.The following results were obtained：In the middle and eastern parts of Qaidam block,infrared bright temperature showed a significant anomalous increase twice in four months prior to the earthquake,the duration of which was approximately one month.No significant anomalous increase was noted between March 1,2004,and February 28,2013.Therefore,we conclude that the anomalous increase in bright temperature recorded prior to the Minxian earthquake was related to that earthquake.Moreover,among all 5 M ≥ 5.0 earthquakes occurring in the middle and eastern parts of Qaidam block between January 1,2004,and September 15,2013,only one showed an anomalous increase of bright temperature prior to the Minxian earthquake,which may indicate that such temperature increases did not appear on the surface prior to M ＜ 5.6 earthquakes in the middle and eastern parts of Qaidam block.Further,such increases were short-term,which indicates the significance of anomalous increases in bright temperature for the occurrence of M6.0 earthquakes in the middle and eastern parts of Qaidam block.
