川滇块体中强震前热红外辐射异常研究

摘要

中强震频发的川滇块体是研究地震前兆信息的热点地区，中强震前存在热辐射异常已被很多震例证实，有必要对川滇块体中强震前的热辐射异常进行系统研究总结，为该地区热辐射的研究应用提供一定的参考。本文以多年MODIS/Terra卫星热红外亮温数据为基础，对2004年4月至2014年8月川滇块体5级以上地震前的热红外亮温低频信息进行了分析。结果表明：(1)川滇块体M≤6.1级的地震震前观测不到大范围的显著热辐射增强异常，这可为该地区大范围显著热辐射增强异常出现后地震震级预测提供一定的参考依据；(2)2014年8月3日鲁甸M6.5级地震前川滇块体存在大面积显著热辐射增强异常，这类异常对该地区6.5级左右的地震具有短期指示意义。%The Chuan–Dian rhombic block where medium to large earthquakes occurred frequently is the hotspot of studying earthquake precursors. The existence of thermal infrared radiation anomalies before strong earthquakes has been confirmed by many earthquakes. For in-depth study and application of thermal infrared radiation in the Chuan–Dian rhombic block, a systematic research on thermal infrared radiation anomalies before strong earthquakes in this area is necessary. In this paper, on the basis of many years’ Moderate Resolution Imaging Spectroradiometer (MODIS) data of infrared brightness temperature determined through satellite remote sensing, the authors analyzed low frequency information of average brightness temperature beforeM≥5.0 earthquakes from April 2004 to August 2014 in the Chuan–Dian rhombic block. The following results were obtained: (1) In the Chuan–Dian rhombic block, the satellite did not observe a large area of significant thermal infrared radiation anomalies beforeM≤6.1 earthquakes, which could help to predict the magnitude of earthquake after the appearance of such radiation anomalies; (2) A large area of significant thermal infrared radiation anomalies appeared before the August 3, 2014, LudianM6.5 earthquake. Such anomaly was a short-term earthquake precursor, which had the significance of indicating the earthquake of magnitudeM6.5 or so in the Chuan–Dian rhombic block.