乌鲁木齐地区构造应力场与中强震活动特征研究

为了做好中强地震的震预报和震后趋快速判定工作，利用乌鲁木齐地区中强震震源机制解，小震平均震源机制解以及Ｓ波偏振方向综合研究了该区域应力场的分布和中强地震的活动特征。

STUDY ON THE TECTONIC STRESS FIELD AND MODERATE EARTHQUAKE ACTIVITY CHARACTERISTICS IN THE URUMQI REGION

For the work of preseismic prediction and rapid postseismic trend judgement of moderate earthquakes can be done well,the distribution of stress field and the characteristics of moderate earthquake activity in the Urumqi region are synthetically studied by using the focal mechanism solution of moderate earthquakes,mean focal mechanism solution of minor earthquakes and P wave polarization direction.The result shows:this region is controlled by horizontal compressional stress in NNE direction,and the sources of moderate earthquakes fault mainly in a reverse,dip strike way;before a moderate earthquake,microseismic activity either is obviously quiet and seismic gap appears,or is dense and sometimes concentrated belt appears;large number of quakes occur in the process of low b value anomaly;most earthquakes are mainshock aftershock type and isolated shock type,and they distribute obviously according to region.