重力数据反演鲜水河断裂三维滑动速率

Xianshuihe Fault Three-Dimensional Sliding Velocity Inversion by Gravity Data

分别将粒子群算法、遗传算法、蒙特卡洛法与位错理论模型相结合,利用已知纯走滑单断层参数正演模拟出的重力变化数据,对单断层三维滑动速率进行反演计算,分析并选取最优的非线性算法。利用2013-09~2014-09和2014-09~2015-04两期地面重力数据反演鲜水河断裂三维滑动速率,结果显示:1)粒子群算法相对于遗传算法、蒙特卡洛法收敛性较好、稳定性强、精确度高;2)鲜水河断裂带具有明显的分段差异性且不同段处滑动速率大小不同,该断裂以左旋走滑为主,整体呈逆冲断层,局部兼有挤压;3)2014-09~2015-04地面重力数据反演鲜水河断裂断层走滑、倾滑参数大于2013-09~2014-09重力数据反演结果,这可能与2014-11-22康定6.3级地震有一定关系。

First of all, this paper uses the particle swarm algorithm, genetic algorithm, and the Monte Carlo method, respectively combined with the dislocation model, to invert three-dimensional sliding rate of the single fault by gravity data simulated by the pure strike-slip fault. By the result, the paper selects the optimal nonlinear algorithm. Then, the three-dimensional sliding rate of Xianshuihe fault is inverted by two phase ground gravity data, recorded from September 2013 to September 2014 and from September 2014 to April 2015. The results show. （1） The particle swarm algorithm, as com- pared with the genetic algorithm and the Monte Carlo method, has good convergence, strong stability and high precision~ but on the whole, they all have certain application value. （2） There are some characteristics of sliding in the Xianshuihe fault zone, which presents a left-lateral strike-slip move- ment, with thrust fault on the whole and extrusion on the local scale. （3） The strike-slip and dip-slip parameter of Xianshuihe fault inverted by gravity data from September 2014 to April 2015 is greater than the inversion result by gravity data from September 2013 to September 2014.