北京地区主要活断层活动参数的重力反演*
董运洪,刘 峡,韩月萍,杜雪松,塔 拉

(中国地震局第一监测中心,天津 300180)

首都圈重力测网; 活断层活动参数; 重力反演; 稳健—贝叶斯最小二乘法

Gravity Inversion of Active Parameters of Main Active Fault in Beijing Area
DONG Yun-hong,LIU Xia,HAN Yue-ping,DU Xue-song,TA La

(First Crust Monitoring and Application Center,CEA,Tianjin 300180,China)

Capital Circle Gravity Network; active parameters of the active fault; gravity inversion; Robust-Bayesianleast-square estimation

备注

采用1991～1999年首都圈重力测网的重力测量资料,根据地质调查结果确定断层初始运动模型,利用稳健—贝叶斯最小二乘方法反演北京地区4条活断层的活动参数(走滑、倾滑、引张)。反演结果表明:在1991～1999年间,北京地区活断层的运动性质均以走滑和垂直升降为主,兼有伸展特征,但运动速率都不大,约为2 mm/a。北京地区北西走向断层反演的运动特征为左旋走滑正断层,北东走向断层反演的运动特征为右旋走滑正断层。

Using the repeated gravity data of the Capital Circle Gravity Network from 1991 to 1999,combined with the initial movement model of the fault determined by geological investigation results,we invert the active parameters(strike-slip,dip-slip and tensile-dislocation)of four active faults in Beijing area by Robust-Bayesian least-square estimation method. The inversion results show that the active fault in Beijing was dominated by strike and slip and vertical lifting motions with extension motion from 1991 to 1999,however their movement rates were small which were about 2 mm/a. The inversed movement characteristic of the faults in NW trend are sinistral strike-slip normal fault,and the faults in NE trend are dextral strike-slip normal fault.