[关键词]
[摘要]
为了分析2014 年2 月12 日新疆于田MS7. 3 地震的热红外亮温异常,收集了以震中为中心30° ~ 45°N、70° ~ 95°E 范围内由中国静止气象卫星FY-2E 观测的亮温资料,资料时间段为2012 年5 月1 日~ 2014 年4 月30 日。应用连续小波变换方法计算了每一个像元的小波相对能谱,得到了分析区域内相对能谱的时空演化过程。分析结果显示,从2013 年10 月开始相对能谱在震中附近出现异常,随后异常逐渐扩大并向阿尔金断裂带和西昆仑断裂带东段区域扩展。从同年11 月开始塔里木盆地西缘的中天山、南天山和西昆仑区域断裂带西段开始出现异常,之后异常区域进一步扩大并向断裂带迁移,最终形成沿塔里木盆地周围断裂带分布的带状异常区域,异常在2013 年12 月下旬和2014 年1 月上旬达到峰值。随着地震的临近,异常区域开始减小,异常幅度也开始减弱,至地震发生时震中区附近异常已经消失,但在阿尔金断裂和中天山区域异常仍存在。于田地震发生后异常迅速衰减,2014 年2 月下旬异常基本消失。
[Key word]
[Abstract]
In order to analyze the seismic brightness temperature anomalies associated with the Yutian earthquake which occurred at Yutian County,Xinjiang on February 12,2014,daily brightness temperature data were collected from Chinese geostationary meteorological satellite FY- 2E,for the period from May 1,2012 to April 30,2014 and the geographical extent of latitude 30° ~ 45°N and longitude 70° ~ 95° E. Continuous wavelet transform method was used to analyze relative wavelet power spectrum (RWPS) of brightness temperature data for each pixel. And the RWPS time-spatial evolution within analysis area was obtained. The results showed that anomaly started at the vicinity of epicentre since October 2013,and anomalous areas gradually enlarged and stretched towards to Altun fault zone and the eastern part of Western Kunlun fault zone. Anomaly began to appear at fault zones at central Tianshan,southern Tianshan and western part of western Kunlun area which located at the western margin of Tarim basin since November 2013. Then anomalous area further enlarged and gathered along fault zones,and eventually developed anomalous belts along fault zones around the Tarim basin. Anomaly area and amplitude reached maximum in late December 2013 and early January 2014. With the impending of earthquake, anomaly area and amplitude dwindled. Anomaly at the vicinity of epicentre disappeared days before the occurrence of the main shock. But anomaly at Altun and central Tianshan areas still lasted. After the main shock,anomaly attenuated quickly and the whole anomaly disappeared in late February 2014.
[中图分类号]
[基金项目]
国家科技支撑计划专题(2012BAK19B02-03)和中国地震局震情跟踪课题(2015010401)共同资助