柯坪断裂东段现今微动态运动监测与研究

Monitoring and Research on Micro Kinematics of the Eastern Segment of the Keping Fault

1997年1月2日-1998年12月31日新疆伽师地震群的发生，使柯坪断裂的滑动速率和运动方向发生了改变。利用MD系列断层仪对柯坪断裂东段的运动特征进行了观测与研究。结果表明，柯坪断裂带东段在伽师地震群前后，垂直滑动速率由0．037mm／a提高到0．069mm／a，水平错动速度由左旋0．033mm／a改变为右旋0．016mm／a；水平运动方向发生了改变，垂直运动强度提高了近一倍；伽师震群发生前后，柯坪断裂东段附近的应力场发生了改变，最大和最小水平应变率的大小虽未变化，但主应变率轴绕顺时针方向旋转了16．7°。

The Jan. 2, 1997 to Dec. 31, 1998 Jiashi earthquake swarm has greatly affected the nearby tectonic activity and fault slip behavior. In this paper, the observation data of MD model fault deformation monitoring system was used to calculate slip rate of the eastern segment of the Keping fault since 1994. The observation and calculation results show that both the horizontal and vertical slip rates changed obviously after the Jiashi earthquake swarm. The sense of the and the vertical slip rate horizontal slip rate changed from right-lateral strike-slip before it to left-lateral slip after it, was 2 times faster than the old one. The horizontal slip rate was 0.033 mm/a in sinistral sense before the Jiashi earthquake swarm, and 0. 016 mm/a in dextral sense after it. The vertical slip rate increased from 0.037 mm/a before it to 0. 069 mm/a after it. The stress field also changed after Jiashi earthquake swarm. Although the magnitude of strain rate here remained unchanged, the direction of the principle strain rate rotated 16.7° clockwise.