伽师及邻近地区GPS地壳形变监测及初步分析

GPS OBSERVATION IN JIASHI AND ITS VICINITY AND THE PRELIMINARY ANALYSIS ON THE OBSERVED DATA

通过对伽师及邻近地区 GPS监测网的优化布设和两期观测资料的分析 ,对伽师及邻近地区的地形变特征进行了探讨 ,认为伽师地区整体上受到正南北向的主压应力 ,但在喀什和乌恰—乌什一带存在着较大的剪应力。伽师地区每年相对于北天山 (哈萨克斯坦 )的运动速度为 19mm。整个南天山地区发生中强地震的可能性将长期存在。

In Aug.-Sep. 1998 and July-Aug.1999,two stages of GPS observation were conducted in Jiashi and its vicinity separately.The ground deformation characteristics in Jiashi area was studied based on the obtained GPS data.The result shows that Jiashi area,as a whole,is compressed by principal stress in SN,and there is stronger shear stress existing in Kashi and Wqia-Wushi areas.The Jiashi area is moving at a speed of 19 mm a year relative to North Tianshan(in Kazakistan).It is considerated that the probability of moderate earthquakes occurring in South Tianshan will exist in a long time.