摘要
利用Morlet小波变换对华北、中国大陆和陕西的地震活动进行了动态周期分析。结果表明，地震活动既存在比较稳定的周期，也有一定时变性。如华北近500a来存在比较稳定的300a周期和60a左右周期，陕西近20a来存在比较稳定的2～3a周期，中国大陆5级以上地震在1910～1980年普遍存在30a左右周期，但在1980年后变为20a左右周期。小波分析揭示的地震活动周期时变性，一方面提示在依据周期规律外推时要应用近期周期分析结果和使用比较稳定的周期；另一方面也告诉周期突变的不可预知性将对趋势预测带来很大影响。
The Morlet wavelet translation method has been used to analyse the dynamic Period ofseismicity in North China, China,s continent and Shanxi province. The results show thatthere exist both comparatively stable periods and some varinble periods with time. For ex-ample, in recent 500 years, some quite stable periods, 300 years or 60 years, exist inNorth China; in recent 20 years, 2 to 3 years' stable period in Shanxi; and for earthquakeswith M >5 in china's continent, there commonly exist 30 year's period from 191O to 1980,but 20 or so years' period after 1980. The period change with time of seismic activity showedby wavelet analysis indicates that one should not only use the recent period and more stableperiod to predict seismic tendency, but also pay attention to the influence of the non-pre-dictable sudden change of period on predictive effects.
出处
《地震》
CSCD
北大核心
1997年第3期257-264,共8页
Earthquake
关键词
小波变换
地震活动性
周期分析
Wavelet analysis, Seismic activity, Period analysis, Tendency prediction
