【摘要】 本文利用改进的红外异常鲁棒估算(RETIRA)法对2015年尼泊尔MS8.1地震震区2007年1月—2015年8月共104个月的NOAA长波辐射日数据进行了处理,获得了该地震前后的红外辐射变化.结果显示,在长达3 158天的时间尺度内,尼泊尔地震破裂面区域的长波辐射值仅在震前半年内呈现显著的异常变化.进一步对喜马拉雅构造带的分段研究表明:震前长波辐射异常出现在尼泊尔地震震中以西区域,说明地震孕育过程中喜马拉雅构造带西侧的应力积累高于东侧,这与前人利用GPS观测资料所得到的该区域应变积累特征一致;长波辐射异常的空间分布主要集中在喜马拉雅构造带南部,这一结果与地震震源机制所显示的发震断层南部区域为断层压缩区、北部为断层拉张区的应力状态相吻合.因此,综合考虑检测到的长波辐射异常所呈现的空间和时间特征,本文认为该异常与尼泊尔MS8.1地震有关.更多还原

【Abstract】 The infrared radiation variation of the 2015 Nepal MS8.1earthquake were analyzed by using improved robust estimator of thermal infrared radiation anomalies(RETIRA)method based on NOAA outgoing longwave radiation(OLR)daily data from January 2007 to August 2015.The results show that the significant OLR anomalies over the earthquake rupture surface only appeared half a year before the event in long-term scale(3 158days).And the study on the Himalayan tectonic segmentation in this paper shows that the OLR anomalies appeared to the west of the epicentral area,revealing that the stress concen-tration on the west side of Himalayan tectonic zone is higher than that of the east during the seismogenic process,which is consistent with the stress variation characteristic based on GPS observation by other researches.The spatial distribution of OLR anomalies were mainly concentrated on the southern Himalayan tectonic zone,which is in agreement with the compressional zone in the southern region and the extensional zone in the northern region of the seismogenic obtained from the focal mechanism.Considering the spatio-temporal characteristics of OLR anomaly variation,the anomalies detected in this study were considered to be related with the Nepal MS8.1earthquake.更多还原