基于GPS技术研究新疆巴楚—伽师6.8级地震的地壳形变特征*
王晓强1,江在森2,杨国华3,李 杰1,杨少敏4

(1.新疆维吾尔自治区地震局,乌鲁木齐 830011; 2.中国地震局地震预测研究所,北京 100036; 3.中国地震局第一监测中心,天津 300180; 4.中国地震局武汉地震研究所,武汉 430071)

地壳运动; GPS; 剪应变; 巴楚—伽师6.8级地震

Study on Characteristics of Crustal Deformation of the Bachu-jiashi MS6.8 Earthquake in Xinjiang Based on GPS Technique
WANG Xiao-qiang1,JIANG Zai-sen2,YANG Guo-hua3,LI Jie1,YANG Shao-min4

(1.Earthquake Administration of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China)(2.Institute of Earthquake Prediction,CEA,Beijing 100036,China)(3.First Crust Deformation Monitoring and Application Center,CEA,Tianjin 300180,China)(4.Institute of Seismology,CEA,Wuhan 430071,Hubei,China)

Crustal motion; GPS; shear strain; Bachu-Jiashi MS6.8 earthquake

备注

利用多期流动GPS观测成果及乌什、塔什库尔干GPS站连续观测资料结果,对2003年2月24日巴楚—伽师6.8级地震前后的地壳形变特征进行了讨论。认为震前震中附近各点以15～20 mm左右的速率向NNW或NNE方向运动并在震中及邻近地区产生高剪应变值集中区,震后震中附近各点运动速率却减为几毫米; 震前出现的高剪应变值集中区震后消失。同时乌什、塔什库尔干GPS连续观测站时间序列在震前2～3月也表现出大幅度突跳。

We discussed the characteristics of crustal deformation before and after the MS6.8 BaChu-JiaShi earthquake,using multiple mobile GPS observation results and continuous observation results in WuShi、Taxkorgan GPS stations.We believe that each point near the epicenter moves to the NNW or NNE direction with the velocity of 15-20mm before the earthquake,which engendering high shear strain concentration area in the epicenter and adjacent area.However,the moving velocity of each point near the epicenter decrease to several millimeters after the earthquake and high shear strain concentration area disappears.At the same time,the time series of Wushi、Taxkorgan GPS continuous observation station appear wide-range sudden jump 2-3 months before the earthquake.