中国西部活动地块运动模型的建立及其运动学分析

Study on current kinematic model of the active blocks in Western China by GPS survey data

中国西部的青藏和新疆地区现代构造变形活动非常强烈,业已证实该区可以进一步划分为塔里木、阿拉善、天山、柴达木和西藏5个活动地块。利用GPS观测资料得到的中国大陆地壳水平运动的速度场,借鉴全球板块运动模型的建模方法,将其视为刚性的地块系统,反演得到各地块相对欧亚板块运动的欧拉矢量,进而求得各地块两两之间相对运动的欧拉矢量,并计算出沿地块边界的相对运动速率。结果显示,与地块边界上的地震滑移矢量,由地质学资料得到的滑移速率,以及GPS数据本身均有较好的一致性,从而也说明了将该地区划分为若干活动地块并视为刚性地块的合理性。

The neotectonic deformation is very strong along the Tibet and Xinjiang zone distributed in Western China. Nevertheless all the observed data of seismology and geology suggested that this area more possibly consists of several rigid blocks., the Tarim （TM）, the Alashan （AS）, the Qaidam （CD）, the Tienshan （TS） and Tibet （TB）. The kinematic model is mainly derived from the Global Positioning System （GPS） velocity data during the latest 10 years＇ observations, based on the method of the global plate model. The resulting Euler vectors predict that the movements of these microplates are consistent with the geophysical and geological observations of relative movements of the plates along their boundaries and that indicates it reasonable to regard these blocks as rigid ones.