Abstract: On the basis of geological data,the three-dimensional geometric model and the segmentation model of the spatial distribution of the Zhuanglanghe faults and the northern marginal fault of Maxianshan are firstly established; Then,with the constraints of slip rates of some studied thoroughly faults,the inferred GPS velocity from the project“Crustal Movement Observation Network of China”is simulated by using“Three-dimensional Deep-fault Dislocation Model”; Finally,the current sliding rates of some other faults are calculated with the inversion method. The results show that there is a rate of 1.4～3.0mm/a of thrust slip on the northern margin fault of Maxianshan,with a left-lateral slip rate of about 3.0mm/a on the middle of the faults,and that there is a thrust slip rate of 0.6～1.2mm/a on the Zhuanglanghe faults with unobvious left-lateral slip component. These results are in accordance with the geological results. The GPS station velocities predicted by the model are consistent with the observed velocities as a whole. It is therefore assumed that these results are all in the reasonable extent predicted before. For the faults with relatively low slip rates and on which the conventional geological methods are difficult to apply,e.g. the Zhuanglanghe faults and the Maxianshan fault,the inversion based on the GPS observations is an effective ancillary means.

Key words: crustal deformation, three-dimensional Deep-fault Dislocation Model, GPS observation

摘要： 根据地质资料,首先建立庄浪河断裂带、马衔山北缘断裂带空间展布的三维几何模型和分段模型,并把地质方法大致推测或估计的各段滑动速率和滑动方式作为先验初值,通过三维深断裂位错模型对GPS观测站点速度场的最佳拟合,反演获得各断裂段的现今滑动速率。结果表明,马衔山北缘断裂有1.4～3.0mm/a的逆倾滑,且中部断层段有约3mm/a的左旋走滑;庄浪河断裂有0.6～1.2mm/a的逆倾滑,走滑分量不明显。这些滑动速率值均在地质方法的推测范围内,且模型预测的GPS站点速度与实际观测值在整体上取得了较好的吻合。本研究表明,对于庄浪河断裂带、马衔山北缘断裂带这样一些滑动速率相对较低且传统地质调查方法较难实施的断裂,基于GPS观测结果的滑动速率反演是一种有效的补充手段。

关键词: 地壳形变, 深断裂位错模型, GPS观测