用GPS数据反演海原断裂带断层滑动速率和闭锁深度  

Inversion of GPS data for slip rates and locking depths of the Haiyuan fault

作　　者：崔笃信[1] 王庆良[1] 胡亚轩[1] 王文萍[1] 朱桂芝[1] 

机构地区：[1]中国地震局第二监测中心,中国西安710054

出　　处：《地震学报》2009年第5期516-525,共10页Acta Seismologica Sinica

基　　金：国家自然科学基金项目(40674057);地震科学联合基金(A07132)资助

摘　　要：以"中国地壳运动观测网络"区域站在海原断裂带附近的所有观测数据及跨断裂GPS剖面观测数据作为约束,用Smith3-D体力模型反演了海原断裂带断层滑动速率和断层闭锁深度.从西到东断裂共分为5段,采用遗传算法拟合GPS水平运动速度场,拟合残差均方根为1.1mm/a.反演结果为:毛毛山断裂左旋走滑运动速率为3.5mm/a,闭锁深度为22.0km;老虎山断裂左旋走滑速率为6.5mm/a,闭锁深度为10.3km;海原断裂带西段、中段和东段的滑动速率依次为4.5mm/a、5.6mm/a和5.5mm/a,闭锁深度依次为8.4km、3.6km和4.3km.表明毛毛山断裂左旋走滑运动速率小,闭锁深度大,有利于应变能的积累,使得该断裂及附近地区存在发生强震的背景.We have inverted Haiyuan faults slipping rates and locking depths by use of Fourier solution of 3-D body force model based on Crustal Movement Observation Network of China and other of GPS profiles data. Genetic algorithm has been used to simulate the GPS velocity field iteratively. The final RMS of fitting residual is 1.1 mm/a. The result reveals that the left lateral slip rate of Maomao Shan fault is 3.5 mm/a and its locking depth is 22 km. For Laohushan fault the slip rate is 6.5 mm/a and locking depth is 10.3 km. The slip rates in western, middle and eastern segment of the Haiyuan fault are 4.0 mm/a, 5.6 mm/a and 5.5 mm/a, respectively, and the locking depths in corresponding segments are 8.4 km, 3.6 km and 4.3 km, respectively. The slip rate of Maomao Shan fault is low, while its locking depth is large, being favorite for strain energy accumulation on this fault.

关 键 词：海原断裂带 3-D体力模型 反演 滑动速率 闭锁深度 

分 类 号：P315.2[天文地球—地震学]