2017年8月9日精河MS6.6地震热红外亮温异常分析

利用相对功率谱方法对风云卫星热红外亮温数据进行处理，发现精河M_S6.6地震前存在明显的前兆异常。异常时空演化特征为2017年7月12日在北天山地震带中、东部和阿尔泰地震带中部开始出现相对功率谱高值聚集现象，随后幅值和面积逐渐增大，持续至7月27日异常面积和幅度达到最大值，然后逐渐减弱，2017年8月14日后基本恢复正常，异常持续大约1个月，8月9日在异常区域边缘发生精河M_S6.6地震。地震震中所在的北天山地震带平均相对功率谱值时序变化特征与异常区域时间演化过程类似，地震发生在平均相对功率谱由最大值恢复至正常背景值的过程中。

Analysis of thermal infrared brightness temperature precursory anomaly before the Jinghe MS6.6 earthquake on August 9,2017

Using the relative power spectrum method to deal with thermal infrared brightness temperature data of the Fengyun satellite, it is found that there is obvious precursory anomaly before occurrence of the Jinghe M_S6.6 earthquake. The characteristic of abnormal temporal and spatial evolution is that high-value aggregation of the brightness temperature power spectrum appears in the middle, east of northern Tianshan seismic belt and the middle of Altai earthquake belt on July 12, 2017, and then the amplitude and area increases gradually, reaches its maximum on the July 27th, then gradually weakens and returns to normal on August 14th, 2017. The anomaly lasts nearly 1 month. The Jinghe M_S6.6 earthquake occurred at the edge of the anomaly area on August 9th. The average power spectrum time series of the Jinghe M_S6.6 epicentral region are similar to the temporal evolution of the anomaly region. The earthquake occurred when the process of the average relative power spectral value restored from the maximum value to the normal background.