“川滇菱块”东部边界的强震活动

STUDY ON THE MACROSEISMICITY IN EASTBOUNDARY OF "SICHUAN-YUNNAN RHOMBUS AREA

本文探讨了西南地区“川滇菱块”东部边界的强震活动情况。研究表明，“川滇菱块”东部边界强震活动在西南地区最为强烈。它集中了川滇地区全部７．６级以上地震，历史强震活动有较明显的活跃期和平静期，且呈现某种自然节律，７级地震显示较好的南北迁移规律，强震时间分布遵从幂函数特征。

The macroseismicity of east boundary of 'Sichuan-Yunnan rhombus area' in sounthwest China was discussed. The results show that: the macroseismicity of east boundary of 'Sichuan-Yunnan rhombus area' is most strongly in sounthwest China. And it includes all earthquakes with Ms≥7. 6 in Sichuan-Yunnan area. Strong earthquakes have activity and quiet Periods clear and present some nature rhythm. earthquakes with Ms=7. 0 show south-north transport phenomen on. Time distribution of strong earthquake follows power function law.