摘要
在简要介绍了川滇地区的构造格局和构造运动特征的基础上 ,讨论了不同观测数据同时用于反演的合理性和物理意义 ,利用 1 998～ 2 0 0 0年观测的 9个测点位移数据和 1 986年以前所测的 1 0个主应力方向数据 ,将边界力和相对权比λ作为待反演参数 ,并考虑了主要活动断裂运动特性 ,进行了弹性有限元数值反演计算。计算结果表明 ,现今川滇地区的构造活动主要力源仍来源于印度板块与欧亚大陆的碰撞 ,菲律宾海板块的挤压作用也不可忽略 。
Considering the rationality and the physical significance of two different kind data including geodesy displacements and main stress orientations with different time scales used simultaneously in inversion,the following views are put forward.(1) The GPS elevation data still have not enough precision for the driving forces acting at the boundaries constraint and lack traditional geodesy observation data (like leveling data).(2) The surveying points that reflect the stress size of deep crust are too few and the depth are not deeper than 5km now.In the meanwhile,the observation data of stress orientation are accumulating in a very high speed.Although the single principal stress orientation does not contain the size information of stress,the principal stress orientations of multiple points contain the relative size information of driving forces acting at the boundaries.(3) Not only the traditional geodesy displacements but also the GPS displacements are the displacement changes (or displacement velocity) over some time and are not the total displacements from the initial state required by the dynamic models,so the difficulty in physics interpretation is obvious when only using displacement data of the study area to inverse the driving forces acting at the boundaries without considering the simplicity in mathematical algorithm.(4) Despite the two different kinds of data with different time scales,the principal stress orientation especially the orientation that reflects the change trend of the area has the changelessness for a very long period,the two different kinds of data can be used jointly if the displacement data has the trend character.(5) The use of two different kinds of data for inversing the driving forces acting at the boundaries not only enriches the observation data required by inversion but improves the geodesy physics interpretation of the inversion results acquired by displacement data with the help of the data of the principal stress orientation.Employing the GPS displacement data and the principal stress orientation data of China area,the research of joint inversion of the plate driving forces acting on the boundaries around Sichuan_Yunnan area is made and a whole set of schemes is presented.After briefly introducing tectonic structure and tectonic kinematic feature of Sichuan_Yunnan area,the rationality and physical sense of different observations simultaneously using for inversion are discussed.Then the inversion com_putation of elastic finite element is made with the forces on the boundary and relative weight ratio as parameters to be inversed using displacement data of nine stations surveyed from 1998 to 2000 and the ten principal stress orientation data observed before 1986.Meanwhile,the kinematic feature of active fracture is taken into account.The results show that the present main driving forces of structure motion of Sichuan_Yunnan area are still from the collision of Indian plate with Eurasian plate and the extrusion effect of Philippine plate can not be ignored.This result demonstrates the succession feature of structure motion of this area nowadays.
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2003年第2期162-166,176,共6页
Geomatics and Information Science of Wuhan University
基金
地球空间环境与大地测量教育部重点实验室开放研究基金资助项目 ( 0 2_0 9_0 2 )
中国科学院创新工程基金资助项目(KZCX2_10 6)
国家自然科学基金资助项目 ( 40 0 740 0 1)
关键词
GPS
主应力方向
联合反演
遗传算法
相对权比
Sichuan_Yunnan area
genetic algorithm
relative weight ratio
joint inversion
