华北地区现今水平运动场的动态特征

Danamic characteristics of nowadays horizontal movement field in North China region

在整体无旋转基准的基础上,采用了以提取中、低频应变信息为主的连续应变模型,处理并分析了《中国地壳运动观测网络》在华北地区400余个GPS测站的复测资料(1999—2001—2004年)和2006年130余个测站的复测资料,获得了1999—2004年、2004—2006年的相对运动速率以及2004—2006年偏离1999—2004年运动的位移结果。结果表明:①华北地区非均匀应变比较明显,不同时段的结果在空间上的表现形式也不一样;②前后两个时段的运动特征具有一定的不一致性;③2006年存在着较明显的偏离位移,并显示了右旋形变的迹象,面应变表现为北、中收缩,南部膨胀的特征;④近两年东西向的压性作用较前明显,北京以南地区是运动的转化地区及面应变象限的准中心地区。这可能表明,在昆仑山口西8.1级地震之后,华北地区又进入了常态能量的积累阶段。

On the basis of region with no-net rotation, and by using continuous strain model focused on extracting medium-low frequency strain information, the paper deals with and analyzes the re-measured GPS data （1999-2001-2004） obtained from more than 400 GPS monitoring stations and also the GPS data re-measured in 2006 from more than 130 GPS monitoring stations in North China in the Project of ＂China Crust Movement Observation Network＂. We gain the relative motion velocity of 1999-2004 and 2004-2006, and acquire the displacement results of the deviation motion of 2004-2006 with respect to 1999-2004, the results suggest： （1） The uneven strains in North China region are obvious, results of different periods distinct from each other in the spatial representation style; （2） The movement characteristics of former and latter two periods are inconsistent to a certain extern; （3） There exists obvious deviation displacement in 2006, and shows a evidence of right revolving deformation, its the surface strain shows the characteristic of surface contraction in central and north part of the region; and superficial expansion in south part of the region; （4） The compression in the EW direction during recent two years is more obvious than before, to south of Beijing it is the area of movement conversion and the quadrant pseudo-center of surface strain. These may suggest that North China region enter the energy-accumulated period after Kunlun Mountain Ms8. 1 earthquake.