【摘要】 本文基于聚类分析方法和聚类树图,对1890年以来环太平洋周边7.5级以上大震的时间间隔特征进行分析,发现起始震级低于8.0级的地震分类特征一致,而起始震级在8.0级以上地震分类特征比较详细:在初步分为地震活跃期和地震平静期时,在地震活跃期内,又可细分为地震活动相对高活跃期(时间间隔1年左右)和地震活动相对低活跃期(时间间隔6年左右)。进而,以8.0级以上地震最后一个活跃期为例,揭示了在地震活跃期内,地震的空间迁移表现出逆时针旋转的特征。更多还原

【Abstract】 Based on cluster analysis,the time interval characteristics of strong earthquakes(M≥7.5)along the circum-Pacific region since 1890 are analyzed and it is found that the cluster characteristics of earthquake time interval are similar when starting magnitude is less than 8.0.When the starting magnitudes are larger than 8.0,the cluster numbers are more detailed.In a preliminary seismic active period,it can be divided into relative high active one(the earthquake time interval is about 1year)and relative low active one(the earthquake time interval is about 6 year).Finally,taking the last active period as an example,a counter-clockwise rotation is shown for the migration of M≥8.0 earthquakes.更多还原