华南地区基于小波变换的地震活动性分析

The Characteristics of Seismic Activity in South China by Using Wavelet Transform

根据1500年以来东南沿海地震带与长江中游地震带的本尼奥夫应变曲线资料,运用小波变换的方法,以不同的小波尺度分析得到了不同时间尺度下的地震活跃期和平静期。结果表明:东南沿海地震带5级以上地震10年尺度内的活动周期大约为300年;1970年以来M_L≥4.0级地震大致呈现出5年左右的周期,目前正在进入M_L4.0级以上地震的活跃期。长江中游地震带5级以上地震可看出较为清晰的"集中活跃-间歇平静"特征,目前处于第4个活跃幕;1970年以来M_L≥4.0级地震,共有3个活跃期,未来数年可能仍处于M_L≥4.0级地震的活跃时段。

With the benioff strain curve data of the southeast coastal seismic belt and middle reaches of Yangtze River seismic zone since 1 500, the paper achieves the seismic active and quiet periods in different time scales by using multi-scale wavelet transform method. The results show that the active period of earthquake with M≥5 in southeast coastal seismic belt in 10 years scale is about 300 years, the active period of earthquake with M_L≥4（since 1970） is about 5 years, and now this area is stepping into an M_L≥4 active period. The middle reaches of Yangtze River seismic belt has an obvious ＂ active-quiet period＂ feature, and currently in its fourth active period. Since 1970, earthquake with M_L≥4 has 3 active periods and it may be still in M_L≥4 active period in the next several years.