【摘要】 2013年4月20日在四川省雅安市芦山县发生了MS7.0地震,造成196人遇难、23人失踪和上万人受伤的重大灾难。为了分析芦山地震前可能与地震有关的热红外亮温异常,收集了以震中为中心98°~108°E、25°~35°N范围内,2011年4月20日至2013年4月19日为期2年,由静止气象卫星FY-2E观测的地表亮温资料。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。结果显示,从1月中旬起,在龙门山断裂带中段开始出现异常,随后异常沿着龙门山断裂逐渐向SW扩展;从3月上旬起,鲜水河断裂带也开始出现异常,之后异常聚集在龙门山断裂和鲜水河断裂的交会区域,在3月下旬异常区域和异常幅度达到最大。随着地震的临近,异常幅度和空间区域逐渐减小,直至4月19日异常还在持续中,地震发生在异常区域的东南边缘。因此认为,热红外异常可能与芦山地震是有关联的。更多还原

【Abstract】 Lushan M 7. 0 earthquake occurred in Lushan County,Ya’an City,Sichuan Province of China,on 20 April 2013,causing 196 deaths,23 people missing and more than 12 thousands of people injured. In order to analyze the possible seismic brightness temperature anomalies which might be associated with Lushan earthquake,daily brightness temperature data are collected from Chinese geostationary meteorological satellite FY-2E,for the period from 20 April 2011 to 19 April 2013 and the geographical extent of 25° ~ 35° N latitude and 98° ~ 108° E longitude. Continuous wavelet transform method is used to analyze the power spectrum of brightness temperature data,for its good resolution both in time and frequency domains. The results show that relative wavelet power spectrum( RWPS) anomalies appeared since 15 January 2013 and still lasted on 19 April. Anomalies firstly appeared at the middle part of Longmenshan Fault zone. Then, they gradually spread towards southwestern part of Longmenshan Fault. Anomalies also appeared along the Xianshuihe Fault since about 1 March. Eventually, anomalies gathered at the intersection zone of Longmenshan and Xianshuihe Faults. The anomalous area and RWPS amplitude increased since the appearance of anomalies and reached maximum in late March. Anomalies attenuated with earthquake approaching,and eventually the earthquake occurred at the southeastern edge of anomalous area. Lushan earthquake was the only obvious geological event within the anomalous area during the time period,so the anomalous changes of RWPS are possibly associated to the earthquake.更多还原