Abstract: Yunnan locates in the east margin of the collision zone between the Indian Plate and the Eurasian Plate in the Chinese continent, where the crustal movement is violent and the moderate-strong earthquakes are frequent. In addition, the area is featured with marked active block movement. Therefore, Yunnan is a perfect place for the research on strong earthquake activity. Through the study on the temporal and spatial distribution of the M>6.7 earthquakes and the related earthquake dynamics in Yunnan in the last century, we conclude that the four seismically active periods which are characterized by the alternative activity in the east and the west part of Yunnan possibly result from the combination of the active and quiescent periods in each of the east part and the west part. And for every 100 years, there may be a period in which strong earthquakes occur in the east and the west parts simultaneously. Besides, the seismicity of strong earthquakes in Yunnan corresponds well to the one in the peripheral region. The seismicity of the great earthquakes in the Andaman-Burma Tectonic Arc Belt indicates, to some extent, the beginning of seismically active period in Yunnan. The seismicity of strong earthquakes in east Yunnan is closely related with the one in Sichuan. The strong earthquakes in Sichuan often occur later than the ones in Yunnan. Further, in the east part of Yunnan, the three procedures including continuous occurrence of moderate-strong earthquakes, quiescent period, and the occurrence of the first strong earthquake may be the style of the beginning of the earthquake active period. The above cognition is helpful to the study of earthquake prediction, seismogenic mechanism, and the dynamics of the plate margin in Yunnan.

Key words: seismicity of strong earthquakes, earthquake prediction, Yunnan area

摘要： 云南地区处于印度板块与欧亚板块中国大陆碰撞带的东缘,地壳运动剧烈,活动块体特征明显,中强以上地震频发,是研究大震活动规律的理想场所。通过过去一个世纪的6.7级以上地震活动的时空分布以及地震动力分析认为,云南地区存在的4个具东西交替活动特征的地震活跃期,可能是东、西部各自地震活跃与平静过程叠加的结果,100a左右可能出现1次东、西部同时爆发大震的时段;云南地区地震活动与外围地区存在较好的呼应关系,安达曼-缅甸弧形带的巨震活动对云南地区地震活跃期的启动有一定的指示意义,而云南东部强震也与四川西部大震密切相关,四川大震活动往往滞后于云南地区;中强地震连发-平静-首发大震可能是云南以东部为活动主体的地震活跃期的启动模式。这些认识对云南地区大震预测、地震机理以及板缘动力学研究会有所帮助。

关键词: 大震活动, 地震预测, 云南地区