西北地震学报2013，Vol.35Issue(2)：272-277,6.DOI:10.3969/j.issn.1000-0844.2013.02.0272
四川芦山7.0级地震卫星热红外异常解析
Analysis of Thermal Infrared Anomaly before the Lushan Ms7.0 Earthquake
摘要
Abstract
Aiming at analyzing the thermal infrared anomaly that occurred before the Ms7.0 earthquake in Lushan,Sichuan,remotely sensed infrared brightness temperature data from China Geostationary Meteorological satellite FY-2C/E was collected,and the infrared data from the prime period from 1:00 to 5:00 Peking time was selected as the data source.By processing the data to eliminate cloud cover and by using the power spectrum transform method,we analyzed the thermal infrared anomalies in the earthquake temporal evolution diagram and the timing curve of the average brightness temperature.The results showed that a month before the earthquake,a small area of thermal anomaly existed just north of the epicenter,and this area showed irregular shapes.With the passage of time,the abnormal range gradually expanded along a certain direction in the tectonic stress field.From April 4,the abnormal area expanded along the northeasterly direction and reached its maximum on April 13,2013.At the same time,a small-scale anomaly was discovered just south of the epicenter,with the epicenter always being at the edge of the abnormal parts.The earthquake cycle related to these thermal anomalies was 64 days,and the thermal anomalies lasted more than 30 days.Before the earthquake,the magnitude of the relative change was greater than 9 times,the greatest in the past two years.From the end of March to the seismogenic day,the average increased sharply,with the abnormalities peaking 3 days before the earthquake,which is similar to the Wenchuan earthquake of May 12,2008.We simultaneously found that the brightness temperature anomaly was distributed consistently along the fault,which should be related to the distribution of active tectonics.The thermal infrared anomalies before the earthquake were fairly obvious and persistent over time,and went through two stages,initial warming and strengthening warming.The abnormal area moved and expanded rapidly along the fault direction.The epicenter of this earthquake was not in the area of maximum abnormality but approached the fault that was near the edge of the anomaly.This situation was consistent with the results of most earthquake cases,and it may be related to the geological structure and the underground environment of the epicenter.These characteristics can provide some clues to determine future seismogenic times and to track the location of epicenters.This study addressed the characteristics associated with the evolution of thermal infrared anomalies and earthquake preparation,and elaborated a new understanding of the relationship between thermal anomalies and the elements of earthquakes.Because this current understanding of the genetic mechanism of thermal infrared anomalies for earthquakes is not yet mature,future work will look at the shock cases and summarize the laws.关键词
四川芦山7.0级地震/静止卫星/热红外遥感/相对功率谱/亮温变化Key words
Lushan Ms7.0 earthquake in Sichuan province/ Geostationary meteorological satellite/Infrared remote sensing/ Relative power spectrum/ Brightness temperature change分类
天文与地球科学引用本文复制引用
张璇,张元生,魏从信,田秀丰,汤倩,高见..四川芦山7.0级地震卫星热红外异常解析[J].西北地震学报,2013,35(2):272-277,6.基金项目
中国地震局兰州地震研究所青年基金(2011Q04) （2011Q04）
国家科技支撑计划课题(2012BAK19B04) （2012BAK19B04）
兰州地球物理国家野外科学观测研究站开放基金(2013Y04) （2013Y04）
