中国大陆主要块体现今运动状态联合反演研究

Joint Inversion on Present Motion State of the Main-Plates in Chinese Continent

基于中国大陆多年来的GPS速度数据和地震矩张量数据,在充分考虑大陆内部构造活动的基础上,联合反演研究了中国大陆主要块体的欧拉运动参数。将两种观测数据的相对权比同欧拉参数一同作为反演参数,利用联合反演模型和优化方法,合理地提取了观测数据中的块体运动信息。研究结果表明:(1)7个亚板块表现出复杂的运动和变形格局,以南北带为分界线,西部从南向北逐渐减弱,西藏亚板块中构造块体的欧拉矢量转速平均约为0.551°/Ma,新疆亚板块中各构造块体的欧拉矢量转速平均约为0.267°/Ma;南北带西部多数块体的运动明显大于东部,华北亚板块的欧拉矢量转速平均约为0.251°/Ma,华南亚板块约为0.283°/Ma。(2)中国大陆地壳的形变具有明显的整体形变趋势,同时亚板块或构造块体之间又表现出构造运动的区域性和差异性。(3)在联合反演中,GPS资料主要作用在于确定地壳运动的现时性,地震矩的作用主要是确定运动的趋势性。利用两种观测数据进行联合反演,可最大限度地提取块体运动的信息。

Based on the data of GPS and seismic moment tensor and considered tectonic motion within theChinese continent thoroughly, the euler parameters of main-plates in Chinese continent are studied throughjoint inversion method. In this study, it is a good idea of inverting relative weight ratio as the inversion parameter with euler parameters together. Using joint inversion model and optimization method, movementinformation in the plates from observations are reasonably derived. The results reveal： （ 1 ） 7 plates take oncomplicated pattern of movement and deformation, the movement and deformation are weakened graduallyfrom south direction to north direction bordered by the South-North Zone, the euler vector rotate speeds inTibet plates average about 0. 551° /Ma, and 0. 267°/Ma in Xinjiang plate, euler rotate speed of the plates inwest area is bigger than that in east area of the South-North Zone, the one in north China sub-plates averages about 0. 251°/Ma, but the one in south China averages about 0. 283°/Ma; （2）The crust deformation inChinese continent has a trend of whole deformation, at the same time the regional nature and difference oftectonic movement between the sub-plates and tectonic plates are presented. （3）In the joint inversion study,the update status of crust movement mainly ascertained by GPS data, but the trend of the movement mainlyascertained by seismic moment tensor data. So the movement information of plates is derived by joint inversion method from two kinds of observations.