基于GPS速度场研究中国大陆块体运动

Study of tectonic block characteristics in China continent based on GPS velocity field

针对中国大陆区域全球定位系统监测网点的加密,采用高精度全球定位系统数据处理方法处理了中国大陆约2 000站的3期GPS观测,获得相对ITRF2008框架的中国大陆高精度、高密度全球定位系统水平速度场。基于此处理结果,对中国大陆6个一级块体及22个二级块体的刚体运动进行了重新分析,求解了各块体上相对可靠的刚体运动参数。进一步利用各块体的刚性参数,分析了块体边界带的相对运动。基于全球框架下的全球定位系统观测结果表明,喀喇昆仑—嘉黎、阿尔金、小江、红河等4个断层近期相对滑动速率较大,预示着这些区域近期发生地震的可能性较大;祁连山、富蕴、山西地堑、大秦岭、张家口—蓬莱、秦岭—大别山、郯庐南段等区域滑动速率较小一般低于5mm/a,与地质调查的结果基本一致。

In this paper,the high density horizontal GPS velocity field in the Chinese mainland was obtained by using high precision data processing methodology.About 2000 stations of the CMONOC project were processed together relative to the ITRF2008 framework.The rigidity body motion of 21II-order active tectonic blocks in China mainland was reanalyzed based on the above GPS velocity filed.It provided a reliable analysis for the rigidity body motion comparing to the previous studies.The analysis of relative motion of block boundary belts was studied by using the rigid block parameters.It showed that the areas with much larger relative slip rates were among Kala-kunlun-Jiali,Arkin,Xiaojiang River and Red river faults boundary from recently GPS monitoring relative to the global framework.It meant these regions had higher possibility for earthquake occurrence in the recent period.Some faults slip rate was less than 5mm/a among Qilian Mountain,Fuyun,Shanxi graben,Qinling Mountains,Zhangjiakou-Penglai Qinling-Dabieshan,and South Tanlu faults boundary,which was agreed well with the results of geological survey.