陕西三维速度场模型建立及形变分析

Establishment of 3D velocity field in Shaanxi and deformation analysis

针对陕西省三维速度场研究成果较少且陈旧的问题,基于该地区最新GNSS大地控制网、陆态网络基准站和流动站等成果,计算陕西省三维速度场模型,分析陕西最近20 a水平和垂直运动情况。将最小二乘配置应用于板块欧拉矢量的计算中,随机信号较好地表征了局部区域的运动,有效改善了水平速度场模型的精度。计算结果表明:在水平方向,陕西地区整体向东南方向运动,平均速度约33.6 mm/a;相比Ⅱ级块体,陕西GNSS点形变速度较小,整体稳定性较高;在垂直方向,关中平原表现为沉降,最大沉降速度为6.3 mm/a,陕北、陕南表现为隆升,其中,陕北最大隆升速度为6.4 mm/a,陕南为5.1 mm/a。

In view of the problem that there are few and outdated research results on the 3 D velocity field in Shaanxi Province,the 3 D velocity filed in Shaanxi was calculated based on the lasted GNSS data of geodetic control network,the reference stations and regional stations from crustal movement observation network of China(CMONOC).Then the horizontal and vertical movement was analyzed for the past 20 years.Least squares collocation was applied to the Euler vector to establish horizontal velocity filed model.The random signal characterized the movement of local area and improved the accuracy of horizontal velocity field model effectively.The results showed that the horizontal velocity in Shaanxi was moving southeast at the average velocity of 33.6 mm/a.The deformation of GNSS points in Shaanxi was small relative to Chinese secondary plate,thus the overall stability of the secondary plate was high.In the vertical direction,Guanzhong Plain was subsidence and the maximum velocity was 6.3 mm/a.Northern Shaanxi and Southern Shaanxi showed uplifting with the maximum velocity of 6.4 mm/a and 5.1 mm/a.