利用中国大陆GPS水平速度场数据,基于块体旋转与块体边界断层闭锁模型,反演了海原-六盘山断裂带中各断裂的闭锁程度与滑动亏损分布,并结合反演结果对该断裂系统的强震危险性进行了分析。结果显示:海原一六盘山断裂带中的金强河断裂、毛毛山断裂和六盘山南段闭锁程度最强;滑动亏损高值出现在金强河断裂、毛毛山断裂和老虎山断裂,而六盘山断裂整段滑动亏损均较小,应变积累缓慢;其他断裂闭锁程度与滑动亏损均相对较小,其中,海原断裂(狭义)闭锁程度最弱,滑动亏损也仅分布于断层浅部。结合历史地震情况,分析认为金强河断裂、毛毛山断裂以及六盘山南段在未来一段时间内强震危险要高于其他断层段。
Using GPS horizontal velocity field data for the China mainland, the locking and distribution of the slip deficit of the Haiyuan-Liupan fault zone was inversed based on a block rotation and fault locking model. We analyzed the potential of the large earthquake using the inversion results. The re-sults show that the locking degree of the Jinqiang River, Maomao Mountain, and the southern seg-ment of the Liupan Mountain fault is the strongest. The level of the slip deficit on Jinqiang River, Maomao Mountain, and the Laohu Mountain fault is relatively high, while the entire Liupan Moun-tain is relatively low and the strain accumulation is very slow. The locking and the slip deficit of other faults are all relative low, especially the Haiyuan fault, where the degree of locking is the weakest and only shallow slip deficit exits. Considering historical earthquakes, the results suggest that the Jin-qiang River, Maomao Mountain, and the southern segment of the Liupan Mountain fault are seis-mogenic faults with large earthquake potential.