Abstract: By using horizontal data during 1999—2015 and based on the block-dislocation model, this paper inverted the spatial distribution of locking degree and slip deficit rate of four main faults, Haiyuan, Liupanshan, Longxian-Baoji and west Qingling faults in northeast margin of Tibetan plateau. Combining the inversion results, the earthquake potentials of the four faults was analyzed. The inversion results show that the locking degree of the southern segment of Liupanshan fault, the northern segment of Longxian—Baoji fault and the eastern segment of West Qingling are the strongest with blocking depth up to 24 km. The slip deficit rate of the eastern segment of the West Qingling fault is largest with average up to 3 mm/a. The southern segment of Liupanshan fault and the northern segment of Longxian—Baoji fault are slightly smaller than that of the northern segment of Longxian—Baoji fault with average up to 1.9 mm/a. Both the locking degree and slip deficit rate of Haiyuan fault are relatively small and distribute in shallow part. The analysis result suggests the earthquake risk of the southern segment of Liupanshan fault, the northern segment of Longxian—Baoji fault and the eastern segment of West Qingling fault are larger than other segments of these faults.

Key words: GPS velocity field, Locking degree, Slip deficit rate, Northeast margin of Tibetan plateau