北祁连-河西地区垂直形变场演化与地震活动关系研究

基于 1972～ 2 0 0 0年北祁连 -河西地区的垂直形变观测资料 ,分析研究了该区垂直形变场的演化及其与地震的关系 ,得到如下结论 :1本区构造运动近 30年来的演化过程为逆继承性运动 -继承性运动增强 -持续继承性运动 -逆继承性运动 -继承性运动这样一个“旋回”过程 ,继承性运动是构造运动的总趋势 ;2垂直形变场演化与地震活动强弱存在一定的相关性 ,但地震活动强弱明显“滞后”于地壳运动 ;31995～ 2 0 0 0年构造运动恢复继承性运动 ,且山区与盆地的差异性运动较 1989～ 1995年有所增强 ,表明本区构造应力场有强化趋势 ,未来几年祁连构造带中东段有发生中强地震的可能。

STUDY ON EVOLUTION OF THE VERTICAL DEFORMATION FIELD AND ITS RELATIONSHIP TO SEISMIC ACTIVITY IN QILIAN MOUNTAIN-HEXI CORRIDOR

By analyzing the vertical deformation field in 1972～2000 in Hexi area,the following results are obtained:①In recent 30 years,tectogenesis reflected by the vertical deformation field undergoes a ‘cyclic’ evolutive process, i.e. counter-inheritance motion,enhanced inheritance motion,persistent inheritance motion,counter-inheritance motion,inheritance motion.The total trend of this motion is inheritent.②This research shows that the vertical deformation is correlative to seismic activity and the strenthening and weakening of the seismicity lag obviously behind crustal movement.③Tectogenesis resumes inheritance motion in 1995～2000,and diversity motion between mountain and basin was stronger than last period,so there is an intensive trend of tectonic stress field,in a few coming years there is probably middle-strong earthquake in middle-eastern segment of QiLian tectonic zone.