Geodesy and Geodynamics
Fault blockade; Sliding loss; Sliding rate; Honghe fault;
Constrained by the horizontal GPS velocity fields in China mainland from 1998 to 2007 and from 2009 to 2017, the movement characteristics of the Honghe fault before and after the 2008 Wenchuan earthquake are studied based on the block-dislocation model. The results show that the average dextral strike-slip rate of the Honghe fault is about 4.5 mm/a after the Wenchuan earthquake. The strike-slip rate of the northern segment increases obviously, followed by the middle segment, while that of the southern segment decreases obviously; the dip-slip rate of the northern segment decreases obviously, while that of the middle and southern segments decreases slightly. After Wenchuan Earthquake, the locking degree and sliding loss of Honghe Fault increased in the middle and North segments, and weakened in the South segment. Recently, the sliding loss of Honghe Fault reached more than 10 mm/a in the north segment and 5-8 mm/a in the middle segment, with an average locking depth of about 20 km. The analysis shows that the Wenchuan earthquake has less influence on the middle and North segments of the Honghe fault, but greater influence on the South segment.