蒙古和新疆亚板块强震时空演化特征

THE CHARACTERISTIC OF THE SPATIO-TEMPORAL EVOLUTION OF STRONG EARTHQUAKES IN MONGOLIA AND XINJIANG SUBPLATE

蒙古亚板块区的强震活动，在时间序列上可划分为4个活跃期3个平静期。活跃期频度低（平均2次），强度大（最大震级7．9～8．0级），持续时间涨落大（最短1年，最长14年，平均7年）；平静期相对稳定，持续时间22-25年。空间演化方面具有阿尔泰山地震带与杭爱山地震区之间交替活动，阿尔泰山地震带内中、南、北段相互迁移的特征。新疆亚板块区的强震活动，在时间序列上可划分为5个活跃期4个平静期，活跃期有强弱之分并呈现交替特征，强活跃期持续时间长（13年），频度高（7～8次），强度大（最大7．5～8．3级），而弱活跃期则相反。在空间演化上相邻活跃期除主体活动区外．还有参与活动区．主体活动区在天山区与兴都库什区之间交替出现．

Strong earthquake activity in Mongolia subplate can be divided four active periods and three quiet periods in time sequence. Frequency of active period is low （average is 2 times）. Its magnitude is large （maximum magnitude is 7 -- 8）. The fluctuation of duration is large （ the shortest time is 1 year, the longest is 14 years, average time is 7 years）. The quiet period is reversely steady. It is 22--25 years. In spatial evolution, strong earthquake alternate to active in seismic zone of Altai Mountain and Hangai Mountain. And strong earthquakes transfer from south to north in Altai seismic zone. And in seismic zone of Altai Mountain, the activities of middle, south and north part have reciprocally transferred characteristic. Strong earthquakes in Xinjiang subplate can be divided five active periods and four quiet periods in time sequence. Active periods appear strong and weak active periods. And they will alternate to appear. The duration of strong active period is long （13 years）, the frequency is high （7--8 times）, and the magnitude is large （maximum is M7. 5 -- M8.3）. However, weak active period has opposite features. In spatial evolution, neighboring active periods exist participant active region besides main active region. Main active region appears alternately between Tianshan area and Hindu Kush area.