宽频带数字资料低频波在大震前的短临前兆信息研究

通过对高台、兰州、成都、安西地震台宽频带数字资料在2001年昆仑山口西8.1级地震,2008年汶川8.0级地震以及2003年山丹、民乐6.1级地震前低频波频谱变化的研究,总结了数字资料在频率域上的短临前兆异常特征,发现0.1~0.14 Hz频幅在震前几天成逐渐增强的趋势。并结合震源区构造特征对前兆机理进行了探讨。认为低频波的产生与静地震和慢地震有关。

Research on Low-frequency Wave of the Broadband Digital Data and the Information of Short-imminent Precursor before Strong Earthquakes

Through the studing on the broadband digital seismic data from Gaotai,Lanzhou,Chengdu and Anxi seismic stations,the spectral variation of low-frequency wave before the west to Kunlun Mountain Pass earthquake with MS=8.1 in 2001,Wenchuan MS8.0 earthquake in 2008 and Minle-Shandan MS6.1 earthquake in 2003,is analyzed,and the characteristics of short-impending term precursory anomaly in the data is summarized in frequency domain.I t is found that the amplitude of frequency in 0.1~0.14 Hz increases gradually in a few days before strong earthquake.The mechanism of the anomaly is discussed also combined with tectonic features of the earthquake source area and the low-frequency wave is considered has relation with quiet-earthquake and slow-earthquake.