基于背景场的地震亮温异常时空演变分析——以2014年新疆于田Ms7.3级地震为例

本文处理了新疆地区2010~2014年的FY-2E卫星热红外亮温数据,基于构建的亮温背景场资料,对2014年2月12日新疆于田Ms7.3级地震前地表红外亮温的时空分布和演变特征进行了分析。研究发现震前亮温异常主要呈条带状分布于塔里木盆地西南缘和东南缘地区,其位置和走向均与于田地震所处断裂带相吻合；异常出现在2014年1月27日(地震前16天),一直持续到2月2日(地震前10天),之后迅速消失；亮温异常十分明显,异常出现时亮温均值相比背景值增幅达8K～10K,异常值增幅可达20K以上。此次亮温异常现象在时空演变的各个方面均与于田地震具有很好的相关性,亮温背景场资料对于地震异常提取具有一定参考价值。

Analysis of Temporal and Spatial Variation Characteristics of Seismic Brightness Temperature Anomalies based on Background fields before Ms7.3 Yutian Earthquake on 2014

This study uses FY-2E Satellite TBB (Temperature of Brightness Blackbody) data of Xinjiang Area from 2010 to 2014 to establish TBB background fields, then analyzes the temporal and spatial distribution and variation characteristics of TBB before Yutian Ms7.3 Earthquake on February 12th, 2014, based on the TBB background fields. The result shows that the TBB anomalies, which distributed like stripes, mainly located on the southwestern and southeastern fringe of Tarim Basin, with the same location and orientation of the fault zone where Yutian earthquake occurred; the TBB anomalies appeared on January 27th, 2014 (16 days before earthquake) and lasted to February 2nd, 2014 (10 days before earthquake), then the anomalies disappeared quickly; when the anomalies appears, the average value of TBB is 8K~10K higher than background value and the value of anomalies can be more than 20K higher as well. According to the result, the TBB anomalies before Yutian Earthquake correlate with the earthquake very well in all respects of temporal and spatial evolution, and the background field has reference value to the extraction of seismic anomalies, to some extent.