基于向错-位错组合模型模拟渭河盆地内主要断层的滑动与转动运动变形,通过数值计算获得断层滑动及转动变形引起的地表水平位移,并与盆地内实测GPS水平位移进行了对比。结果表明:采用向错-位错组合模型能够完整地描述断层实际的滑动与转动运动变形状态,组合模型模拟断层滑动与转动引起的地表水平位移与实测GPS水平位移,无论在量级或是运动趋势上均具有较好的一致性特征。
The Weihe Basin,which is situated in the middle of China,was the area of interest for this study.The basin is several hundred kilometers long and forms an S-shape,representing a deep rift that divides China into eastern and western parts.Bounded by the Ordos,North China,and South China blocks,the Weihe Basin is the accommodation zone for the differential motion of these three blocks and also the border and decoupled strip of tectonics between western and eastern China.We simulated the deformation state of the main fault slip and rotation in the Weihe Basin using a combined disclination-dislocation model.The horizontal displacements caused by fault slip and rotation were acquired through numerical calculation and compared with GPS-measured horizontal displacements in the Weihe Basin.The results were as follows.(1)The movements of fault slip and rotation can be described well by the combined disclination-dislocation model,and there are only small differences between the modeling results and monitoring data.(2)Use of only the dislocation model does not adequately describe the activity features of the faults within the Weihe Basin that show slip and rotation,and there are significant differences between the model results and monitoring data,particularly in the direction of crustal movement.(3)Compared to the dislocation model,there is good consistency between the simulated horizontal displacements of the combined model and the measured GPS results.