【摘要】 中国地质大学(武汉)三峡库区地质灾害研究中心安装在三峡库区的次声波监测仪在芦山地震(2013年4月20日,MS7.0)和玉树地震(2011年6月26日,MS5.2)震前都接收到有效的异常信号。根据不同台站接收到的次声波异常信号,配合Matlab滤波和小波分析等手段,得出:芦山地震震前次声波信号的频率主要集中在(0~4)×10-3 Hz;玉树地震震前次声波信号的频率主要集中在(0~5)×10-3 Hz,且地震震级越大,震前次声波信号振幅越大。根据野三关和秭归的次声波监测仪在玉树地震震前接收到的次声波异常信号的时间差和震中与次声波监测仪台站之间的距离差,估算出玉树地震震前超低频次声波的波速约为6.4m/s。为探讨地震短临预报的可行性,文中设计了一个大三角套小三角的次声监测阵列以实现震中定位。更多还原

【Abstract】 The infrasound monitors installed in the Three Gorges Reservoir Area by the Three Gorges Research Center for Geo-hazard of China University of Geosciences(Wuhan)had received abnormal signals before the onset of the Lushan earthquake(MS7.0,April 20,2013)and Yushu earthquake(MS5.2,June 26,2011).We analyzed the abnormal signals received by different stations using both Matlab filtration and wavelet analysis.The frequency of the precursory infrasonic signals predating the Lushan earthquake is mainly(0-4)×10-3Hz,and that of the Yushu earthquake is mainly(0-5)×10-3 Hz.The amplitude of the precursory infrasonic signal increases with the earthquake magnitude.After we analyzed the time difference of the abnormal signals received by Yesanguan and Zigui stations and the distance between the epicenter and the stations,we calculated that the velocity of the precursory ultra-low frequency infrasonic wave of the Yushu earthquake is 6.4m/s.To investigate the possibility of short-term and impending earthquake predictions,we developed a monitoring array,a big triangle array enclosing a small triangle array,to detect the location of the epicenter for the further researches.更多还原