【摘要】 本文应用Morlet小波变换定量分析了日本不同区域地震活动的周期特征。结果表明,日本各区域存在着稳定的地震活动周期,其中北部地区的显著周期为20年和50年左右;中部地区为100年左右;南部地区20年和50年左右。1840年以来8级以上地震的时空分布特征显示,日本南部地区仍存在可能发生特大地震的危险。更多还原

【Abstract】 This article divided the Japan region into three areas,then quantitatively analyzed its′ seismic activity period and its significance test using the method of Morlet wavelet.The results show: ① There are two principal periodic components,20 years and about 50 years in the north part of Japan.For the middle part,the principal period is about 100 years.And the principal periodic components are about 20 years and 50 years in the southern part.② On the basis of the spatio-temporal distribution characteristics of M≥8.0 earthquakes,we held the opinion that there is still the risk of great earthquakes in southern Japan.更多还原