青藏高原东北缘近期水平形变场分析

ANALYSIS OF RECENT HORIZONTAL DEFORMATION IN THE NORTHEASTERN MARGIN OF THE QINGHAI-TIBETAN PLATEAU

利用2011-2013年青藏高原东北缘地区GNSS水平形变观测与处理结果,分析了青藏高原东北缘近期水平形变场,得出以下结论：2011-2013的水平运动清晰有序,相对运动一般在15 mm/a以内;区域主压应变优势方向为东北-西南向,值域在±40×10-9/a之内,最大主压应变区呈带状分布于研究区域南部;从应变率的膨胀与收缩空间范围来看面收缩占优势,表明该区是以压性为主积累应变能,面收缩较大值主要分布在东南角;最大剪切应变率较大的值域以条带形式展布在区域内,一个是祁连构造活动带,另一个是其南面靠近区域南端且与其平行的条带上;水平旋转量在空间上的分布比较有序,左旋活动与右旋活动呈区域性展开。

Resent horizontal deformation field in the northeastern margin of Qinghai-Tibetan plateau was analyzed, using GNSS observation data from 2011 to 2013. The results indicate that：The horizontal movement from 2011 to 2013 is obviously,with the rate of 15mm/a or lower;The direction of principal compressive strain is SE-NW,with the strain rate of ±40 ×10^-9/a,The region of maximum main strain locates in the south of the study area in a belt; Dominent surface shrinkage indicates that the strain energy is accumulated in compressional way, the largest surface shrinkage value mainly distributed in the southeast corner;The regings with maximum shear strain rate are showed as belts, one of them is Qilian Tectonic Belt, another is in the south of the study area, parallelling with the Belt ; Leftlateral area and dextral area distribute in belt.