Investigation of features of present 3D crustal movement in eastern edge of Tibet plateau
Investigation of features of present 3D crustal movement in eastern edge of Tibet plateau
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发表时间：
2013
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通讯作者：
W. Shuang
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作者：
W. Shuang
利用中国地壳运动观测网络（CMONC）和中国构造环境观测网络（TEONC）1999-2011年的GPS运动观测资料，计算了西藏东缘地区的GPS速度场。然后，结合该地区的动力背景和大事件，分析了GPS速度的时变特征和空间分布，最后通过与1970年代-2011年水准测量的垂直运动进行比较，探讨了三维地壳运动的特征和机制。结果表明：① GPS水平速度的大小和方向的不同主要受青藏高原的挤压和旋转作用以及青藏高原的变化状态的影响。不同阶段的运动也可能与大震的孕育和爆发有关（特别是汶川地震发震断层及邻近地区）汶川8.0级地震前处于挤压状态的龙门山断裂带，目前处于松弛状态而与龙门山断裂相邻的巴颜喀拉地块北缘和川滇地块东缘的应变能仍在积累。
In this paper,we derived the GPS velocity field at the eastern edge of Tibet from the campaign GPS measurement implemented by the CMONC(China Crustal Movement Observation Network)and TEONC(China Tectonic Environment Observation Networks)in 1999—2011. Then,we analyzed the time-depended features and the spatial distributions of the GPS velocity, integrating with the dynamic background and the large events in this area.At last,we investigated the characteristics and mechanism of 3D crust-movement,by comparing to the vertical movement from leveling measurements in 1970s—2011.The results indicated that:① The different magnitude and direction of GPS horizontal velocity are mainly ruled by the effects of extrusion and rotation from the Tibet plateau and the mutative state of motion in different stage may also relate to the pregnancy and erupting of large earthquake(especially the seismogenic fault and the adjacent areas of Wenchuan earthquake).②The features of the crust movement are related to the dynamic environment and the activity from subsurface.This implied that the movements are inherited.③The Longmenshan fault zone which was under compression before the Wenchuan MS 8.0 earthquake is in the stage of relaxation and adjustment now.While,the strain energy of the north edge of Bayankela block which is close to the Longmenshan fault and the eastern edge of Chuandian block is still accumulating.