红河断裂带闭锁程度与滑动亏损分布的GNSS反演

使用1999~2007年及2009~2013年2期GPS速度场,利用TDEFNODE负位错-块体模型反演红河断裂带的闭锁程度和滑动亏损速率。结果表明,红河断裂带以右旋走滑为主,兼有部分拉张和挤压,2008年以前红河断裂平均走滑速率为3.8±2.5 mm/a,平均倾滑速率为1.2±2.5 mm/a,北段和中段表现为拉张,南段则为挤压。红河断裂带北段和中段0~15 km的闭锁系数在0.8~0.99之间,滑动亏损速率为4.5 mm/a,易于应变能的快速积累;南段0~10 km的闭锁系数在0.8~0.95之间,滑动亏损速率为4 mm/a。2008年以后,中段闭锁程度和滑动亏损速率有所减小,南段闭锁程度与亏损速率有所增大。

GNSS Inversion of Fault Locking and Fault Slip Deficit of the Red River Fault Zone

In this paper, we use the GPS velocity fields of 1999-2007 and 2009-2013, and the negative dislocation-block model of TDEFNODE to invert fault locking and slip deficit velocity of the Red river fault zone. The results show that the Red river fault zone is dominated by right-lateral strike-slip, with some extension and compression. Before 2008, the average strike-slip rate and dip-slip rate of the Red river fault zone is 3.8±2.5 mm/a and 1.2±2.5 mm/a, the northern and middle segments exhibit tension, and the southern segment exhibits compression. The locking fraction of the northern and middle segments between 0 to 15 km depth are from 0.8 to 0.99, and the slip deficit rate is 4.5 mm/a, for which it is easy to accumulate strain energy quickly. The locking fraction of the southern segment between 0 to 10 km depth is from 0.8 to 0.95, and the slip deficit rate is 4.5 mm/a. After 2008, the fault locking and slip deficit rate in the middle segment decrease, and the fault locking and slip deficit rate in the southern segment increase.