对MODIS/Terra卫星遥感红外亮温月距平图像进行了研究,结果表明,在汶川8.0级地震前2年、玉树7.1级地震前1年,遥感红外亮度温度均出现了明显的大幅度升温异常,且异常面积较大,达几十万平方公里,距离发震时间较近的升温异常幅度更大,升温面积更大。汶川地震前升温异常面积比玉树地震前的大,这可能表明异常面积大小与地震震级大小存在一定关联。亮温月距平图像异常次数统计结果表明,1年里出现1～3个月升温异常为背景水平,1年里出现大于等于6个月的异常次数对升温地区未来7级以上强震发生时间具有1～2年的中期指示意义。
Analyzing the monthly departure image of the remote sensing infrared bright temperature(BT)of MODIS/Terra satellite,we obtained the following results:Firstly,the remote sensing infrared bright temperature appeared significant anomalous increase in the very large area,up to more than 150000 km2 in two years before Wenchuan M8.0 earthquake and in one year before Yushu M7.1 earthquake,and the occurrence time of earthquake was closer,the anomalous increase range of the BT was higher and the area of it was larger.Secondly,the anomalous increase area of BT before the Wenchuan M8.0 earthquake was larger than that of Yushu M7.1 earthquake,which may indicate that there was a certain correlation between the size of anomalous area and magnitude.The statistic of anomalous numbers in monthly departure image of BT showed that anomalous increase of BT of continuous three months in one year was considered as the background level,and the anomalous increase of BT of more than six months in one year,which had medium term indicating significance for the occurrence time of M≥7.0 strong earthquake in BT increase area in 1～2 years.
