川滇地区下地壳流动对上地壳运动变形影响的数值模拟  

NUMERICAL SIMULATION OF THE INFLUENCE OF LOWER-CRUSTAL FLOW ON THE DEFORMATION OF THE SICHUAN-YUNNAN REGION

作　　者：王辉[1] 曹建玲[2] 张怀[2] 张国民[1] 石耀霖[2] 申旭辉[1] 

机构地区：[1]中国地震局地震预测研究所,中国北京100036 [2]中国科学院研究生院计算地球动力学实验室,中国北京100049

出　　处：《地震学报》2007年第6期581-591,共11页Acta Seismologica Sinica

基　　金：国家重点基础研究规划项目"活动边界带的动力过程与强震预测"(2004CB418406);地震预测研究所基本科研业务专项(02076902-03);科技部"国家地震网络计算系统建设"项目(2005DKA64000)资助

摘　　要：根据活动断裂分布和区域流变结构建立川滇地区三维有限元模型,采用上地壳为弹性介质,下地壳和上地幔为Maxwell体的粘弹性模型,模拟川滇地区地壳现今运动和应力分布,探讨川滇地区地壳运动变形的动力学机制.通过4种不同边界条件和深度分层结构有限元模型的计算结果的对比,认为川滇地区绕喜玛拉雅东构造结顺时针旋转的地壳运动模式主要受川滇地区特殊的边界动力作用控制,川滇菱形块体下地壳流动对上地壳的拖曳作用亦不容忽视.同时,川滇地区各块体的现今地壳运动场和应力场还受到区域主要活动断裂带的影响,呈现分块特征.On the basis of distribution of active fault and regional rheological structure, a three-dimensional finite element model of Sichuan-Yunnan region, China, is constructed to simulate contemporary crustal motion and stress distribution and discuss the dynamic mechanism of crustal motion and deformation in the Sichuan-Yunnan region. Linear Maxwell visco-elastic model is applied, which includes the active fault zones, the elastic upper crust and viscous lower crust and upper mantle. Four different models with different boundary conditions and deep structure are calculated. Some conclusions are drawn through comparison. Firstly, the crustal rotation about the eastern syntaxis of the Himalaya in the Sicuan-Yunnan region may be controlled by the special dynamic boundary condition. The drag force of the lower-crust on the upper crust is not negligible. At the same time, the main active fault zones play an important role in the contemporary crustal motion and deformation in Sichuan-Yunnan region.

关 键 词：川滇地区 地壳运动 下地壳流动 数值模拟 

分 类 号：P315.3[天文地球—地震学]