银川盆地主要活动断裂的GPS观测研究

GPS Observation of Main Active Faults in Yinchuan Basin

摘要: 本文以已有的GPS观测资料为主，并在一些关键的构造部位进行适量的流动GPS建站和观测，在此基础上，利用defnode程序反演了银川盆地各主要活动断裂的滑动速率，并结合GPS跨断层速度剖面与应变分析银川盆地主要活动断裂的地壳形变特征。结果表明：四条断层垂直于断层的运动速率均小于平行于断层的运动速率；在剖面区域，四条断层均为右旋走滑运动，其中，黄河断裂的右旋走滑速率最大；贺兰山东麓断裂、芦花台隐伏断裂拉张，而银川平罗隐伏断裂、黄河断裂挤压，其中黄河断裂两侧垂直于断层的速率相当，但挤压应变量值较大，可能存在闭锁。断层滑动速率反演结果表明：四条断层的走滑运动速率均大于倾滑运动速率，但相差不大。

Abstract: Based on the existing GPS observation data and some mobile GPS stations and observations in some key tectonic locations, the slip rates of the main active faults in Yinchuan Basin are inverted by defnode program, and the main active faults in Yinchuan Basin are analyzed by GPS cross-fault velocity profile and strain analysis. The results show that the trans-fault velocity profile and trans-fault strain rate show that the vertical velocity of the four faults is less than that of the parallel faults; in the section area, the four faults are dextral strike-slip movement, of which the dextral strike-slip rate of the Yellow River fault is the largest; the eastern foot of Helan fault and Luhua fault are the largest. While the Yinchuan Pingluo Hidden Fault and the Yellow River Fault are extruded, the velocity of the two sides of the Yellow River Fault perpendicular to the fault is the same, but the compression strain value is larger, and there may be blockade. The inversion results of fault slip velocity show that the strike-slip velocity of the four faults is higher than that of dip-slip velocity, but the difference is not significant.