广西区域现今地壳运动构造特性研究

利用多期GPS观测资料计算了广西区域ITRF2000框架下的三维速度场、主应变参数及区域参考框架下的三维形变速率和形变运动趋势,研究了该区域现今地壳运动速度场及内部形变规律。结果表明,广西区域随同南华亚板块作SE-NW方向的逆时针运动,在ITRF2000框架下的东西向速率为29.3 mm/a,南北向速率为-13.4 mm/a,垂向平均速率为2.3 mm/a;区域内部现今地壳运动的形变量较大(约4 mm/a),主张应变率(5.48×10-9/a)大于主压应变率(3.70×10-9/a),地壳应变表现为拉张为主,主应变轴为N43.19°E。

Present-day Tectonic Characteristics of Crustal Movement in Guangxi Area

In order to monitor present-day crustal motion and internal deformation rule in Guangxi area,repeated GPS campaigns(1998,1999,2003,2004 and 2007) are used to calculate the 3D velocity field relative to ITRF2000,principal strain parameters and the 3D deformation velocities and deformation trends in a regional reference frame.The results show that Guangxi area along south China plate moves anticlockwise in SE-NW direction at the rate of 2.3 mm/a,and the average velocity in east-west direction is 29.3 mm/a,and the average velocity in south-north direction is-13.4 mm/a and the average vertical velocity is 2.3 mm/a.The present-day crustal movement in regional reference frame is relative large(about 4 mm/a),and the principal tensile strain rate(5.48 10-9/a) is larger than the compressive strain rate(3.70×10-9/a),Guangxi area is mainly under the extension strain in the direction of N43.19°E.