摘要
利用2008年4月28日0时至5月12日13时许昌地震台地震连续波形资料,对安德列亚诺夫群岛7.0级、日本东海岸近海7.1级和汶川8.0级地震3次M≥7.0地震前地脉动变化情况进行了频域、振幅的量化分析,得出如下结论：3次地震前三分向都记录到了地脉动异常,水平向较垂直向明显;傅立叶谱0.2 ～0.3 Hz谱振幅值出现较大变化,进程上具有快速增大-达到最大值-下降-下降过程中发震的特征;地脉动异常分别在3次地震前2.3、3.3、2.9d出现,属临震异常.
Basing on the seismic continuous waveforms from 12：00 am on Apr.28 to 1：00 pm on May.12 in 2008 recorded by Xuchang Station,we quantitatively analyzed frequency domain and amplitude of microtremor variation before three M ≥ 7.0 earthquakes,including Andrea Ivanov Islands M7.0 earthquake on Apr.2,2008,East coast of Honshu offshore M7.1 earthquake on Apr.8,2008 in Japan and Wenchuan Ms8.0 earthquake on Apr.12,2008 in Sichuan.The conclusions was obtained as following：the microtremor anomalies were recorded by three three-component of seismometer before three earthquakes,and was obvious in the vertical component.The 0.2 ～ 0.3 Hz spectrum amplitude value of Fourier spectral changed greatly,and the process had the characteristic that the earthquake occurred in the process of rapid increase-reach to maximum-decrease-decrease.The microtremor anomaly was appeared in 2.3,3.3,2.9 days before three earthquakes,which were impending anomaly.
出处
《地震研究》
CSCD
北大核心
2014年第1期73-78,171,共6页
Journal of Seismological Research
基金
中国地震局地球物理研究所基本业务专项(DQJB11C11)
关键词
地脉动
地震前兆异常
傅立叶谱
许昌地震台
microtremor
earthquake precursory anomaly
Fourier spectrum
Xuchang Station
