珊溪水库地震与构造地震波谱时-频特征的对比研究

基于2002~2006年浙江地震台网记录的数字化波形资料,利用时-频分析方法,研究了珊溪水库诱发地震和构造地震波谱的时-频特征,发现两者的P波波谱存在差异:1)水库诱发地震P波主频低于构造地震;2)水库诱发地震P波频率成分比构造地震丰富,能量密度频谱随频率轴展布较宽,且出现多个能量较强的频率段;3)水库诱发地震P波能量强度的峰值在整个波列中出现时间较构造地震早且能量衰减快。

CONTRAST OF TIME-FREQUENCY CHARACTERISTICS OF WAVE SPECTRUM BETWEEN SHANXI RESERVOIR INDUCED EARTHQUAKE AND TECTONIC EARTHQUAKE

On the basis of the digital seismic wave data from 2002 to 2006 recorded by the station network in Zhejiang province,with time-frequency analysis method,the time-frequency characteristics of wave spectrum of induced earthquakes in Shanxi reservoir and tectonic earthquakes in Zhejiang have been investigated.It is found that there are differences between them:1) the main frequency of induced earthquake is lower than that of tectonic earthquake;2) the P-wave frequency components of induced earthquake in Shanxi reservoir are more abundant than that of tectonic earthquake,the former's energy density spectrum spreads more broadly along frequency axes,and it has many frequency segments with intense energy;3) the maximum value of energy intensity of P-wave of induced earthquakes occurres in all wave train earlier than that of tectonic earthquake and the energy decays quickly.