利用均线差值振幅波动水平分析汶川、雅安芦山、九寨沟地震前热红外异常  

Analysis of thermal infrared anomalies before Wenchuan,Yaan Lushan and Jiuzhaigou earthquakes by using amplitude fluctuation level of mean difference

作　　者：廖洪月 董娜 王刚 Liao Hongyue;Dong Na;Wang Gang(Xi’an Earthquake Agency,Xi’an 710007,China;Xi’an Earthquake Monitoring Center,Xi’an 710007,China)

机构地区：[1]西安市地震局,西安710007 [2]西安市地震监测中心,西安710007

出　　处：《地震科学进展》2021年第8期352-361,共10页Progress in Earthquake Sciences

摘　　要：针对2008年汶川MS8.0地震、2013年雅安芦山MS7.0地震和2017年九寨沟MS7.0地震前后出现的热红外现象,对MODIS卫星1 km高分辨率亮度温度的原始数据进行均线差值振幅波动水平分析发现:①这3次地震前在震中附近区域均出现显著的差值振幅变化异常,先为低值异常,低至历史平均水平的50%以下,后又演变为高值异常,高值异常峰值均大于历史平均水平3倍以上;②汶川地震、雅安芦山地震、九寨沟地震分别在高值异常峰值的55天、35天、22天后发生;③异常优势分布区域并不在震中区域:汶川地震震前异常区主要位于震中西北区域的柴达木块体,雅安芦山地震、九寨沟地震震前异常区域位于震中西部的巴颜喀拉块体,其中,汶川地震震前异常区域面积远远大于后者。Based on the thermal infrared phenomena before and after the 2008 Wenchuan MS8.0 earthquake,the 2013 Yaan Lushan MS7.0 earthquake and the 2017 Jiuzhaigou MS7.0 earthquake,the amplitude fluctuation level of the mean difference of the original MODIS satellite 1 km high-resolution brightness temperature data was analyzed.①Before these three earthquakes,there were significant difference amplitude changes in the area near the epicenter,which were low value anomalies,lower than 50%of the historical average,and then developed into high value anomalies,and the peak values of high value anomalies were all more than 3 times of the historical average.②Wenchuan earthquake,Yaan Lushan earthquake and Jiuzhaigou earthquake occurred 55 days,35 days and 22 days after the anomalous peak value,respectively. ③ The anomalous predominance is not located in the epicenter:The anomalous preseismic area ofWenchuan earthquake is mainly located in the Qaidam block in the northwest of the epicenter,and the anomalouspreseismic area of Yaan Lushan earthquake and Jiuzhaigou earthquake is located in the Bayan Hala block in the west ofthe epicenter. Among them,the anomalous area before Wenchuan earthquake is much larger than the latter.

关 键 词：汶川地震 雅安芦山地震 九寨沟地震 热红外异常 差值振幅变化 

分 类 号：P315.75[天文地球—地震学]