海原断裂带库仑应力积累  

Coulomb Stress Accumulation along Haiyuan Fault Zone

作　　者：崔笃信[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,陕西西安710054

出　　处：《地球科学（中国地质大学学报）》2009年第4期641-650,共10页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(No.40674057);中国地震科学基金(No.A07132)

摘　　要：用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Smith3D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,计算了库仑应力积累率和地震矩积累率.采用遗传算法拟合GPS水平运动速度场,拟合的最后残差均方根为1.2mm/a.反演结果为:第一段毛毛山断裂左旋走滑运动速率为3.6mm/a,闭锁深度为22km;第二段老虎山断裂左旋走滑速率为10.5mm/a,闭锁深度为11.4km;第三、四、五段(海原断裂带西段、中段和东段)滑动速率依次为3.5mm/a、5.8mm/a、5.7mm/a,闭锁深度依次为8.5km、3.6km、4.3km.海原断裂带库仑应力积累率为0.48～1.59MPa/100a,毛毛山断裂地震矩积累率较大,但库仑应力积累率较小;老虎山断裂库仑应力积累率和地震矩积累率均比较大;海原断裂带(狭义)中西段库仑应力积累率最大.We caculate Coulomb stress accumulation rate and moment accumulation rate through inversing Haiyuan fault slip ping rates and locking depths by using a Fourier solution of 3D body force model with constrains of CMONOC and GPS profiles data. Genetic algorithm has been applied to simulate the GPS velocity field. The last fitting rms residual is 1.2 mm/a. The result reveals that the slip rate of left lateral of Maomao Shan fault is 3. 6 mm/a, and 22. 2 km for the locking depth. For Laohushan, its slip rate is 10.5 mm/a and 11.4 km for locking depth. The slip rate in western segment, middle segment and eastern segment of Haiyuan fault （in narrow sense） is respectively 3. 5 mm/a, 5.8 mm/a and 5.7 mm/a, and 8. 5 km, 3.6 km and 4. 3 km for the locking depth. The Coulomb stress accumulation rates are 0. 48-1.59 MPa/100 a along Haiyuan fault zone. The Coulomb stress accumulation rate is large but the moment accumulation rate is small in Maomaoshan fault. In Laohushan fault both the Coulomb stress accumulation rate and moment accumulation rate are large. The Coulomb stress accumulation rates in the middle and western segments of Haiyuan fault （in narrow sense） are largest in all segments.

关 键 词：海原断裂带 3D体力模型 滑动速率 闭锁深度 库仑应力积累率 地震距积累率 地震 

分 类 号：P631.4[天文地球—地质矿产勘探]