利用GPS研究汾渭断陷带现今变形

Contemporary Deformation of the Fenwei Faulted Zone From Global Positioning System Data

汾渭断陷带是一个地震危险程度高的地区。本研究使用相对于固定欧亚大陆覆盖中国大陆的最新GPS数据,通过构造速度剖面分析发现:尽管鄂尔多斯块体、华北平原和华南块体正在向东南方向移动,但它们之间的相对运动却明显不同;渭河地堑内部虽然基本没有剪切滑移,但其拉张速率非常显著;山西地堑系统具有大致相等的拉张和右旋走滑分量;相对于鄂尔多斯块体,刚性华南块体和华北平原的快速向东南运动,对汾渭断陷带施加了强烈的构造拉张,形成了汾渭断陷带现今的扭张变形。

The Fenwei faulted zone is an area with a high degree of earthquake risk.This study uses the latest GPS data relative to the fixed Eurasian continent covering the Chinese mainland.Through the analysis of the tectonic velocity profiles,it is found that although the Ordos block,the North China Plain and the South China block are moving to the southeast,the relative movement among them is obviously different:although there is basically no shear slip inside the Weihe graben,its extension rate is very significant;the Shanxi graben system has roughly equal extensional and right-lateral strike-slip components;compared to the Ordos block,the rapid southeastward movement of the rigid South China block and the North China Plain imposed a strong tectonic extension on the Fenwei faulted Zone,forming the current transextensional deformation.