摘要
分析了高斯距离加权格网法计算应变率的原理和特征,研制了相应的计算程序,并用于华北地区现今地壳应变特征研究。基于华北地区1999-2009年的GPS观测结果,研究了确定高斯平滑半径的原则和方法,并给出华北地区地壳形变多个应变率物理量的分布。结果表明,基于150km高斯平滑半径计算水平速度梯度能够较好地分辨华北地区的应变率空间变化特征,首都圈地区地壳以张渤带上的左旋剪切为主,其中唐山-秦皇岛地区同时存在南北向的拉张变形;山西带整体表现为沿断裂的右旋剪切变形,同时兼具＂南挤北张＂特性;郯庐断裂带整体形变特征不显著,在南北两端局部区域存在较小的剪切形变;鄂尔多斯块体内部比较稳定,北缘以拉张和左旋剪切变形为主,西缘表现为左旋剪切以及EW向的挤压特征,南缘的秦岭块体南北两侧分别具有左旋剪切和右旋剪切的特性,东西两侧分别表现为正断拉张与逆断挤压特征。
Based on Gaussian distance weighting theory,the paper developed a MATLAB program to compute variables as strain rate in the average distributed grid points in the North China district by using the GPS horizontal velocity derived from GPS observation data from 1997 to 2009.The computing results proved that it is reasonable to choose 150 km as the Gaussian smooth radius.The capital area displayed left-lateral shear along the Zhang-Bo fault zone,while the Tangshan-Qinhuangdao district had extensional performance in the north-south direction.The Shanxi belt presented right-lateral shear deformation overall,with tension deformation in the north part and extrusion movement in the south part.The deformation along the Tan-Lu fault zone was insignificant but with small shear movement in part of its north and south districts.The Ordos block was stable in the interior,but displayed left-lateral shear accompanied by extension in the north rim and extrusion in the west rim.The Qinling block that is in the south rim of Ordos block displayed left-lateral shear and right-lateral shear at its north and south sides respectively,along with extrusion and extension at its west and east sides.
出处
《大地测量与地球动力学》
CSCD
北大核心
2015年第1期7-12,共6页
Journal of Geodesy and Geodynamics
基金
国际科技合作项目(2010DFB20190)
国家自然科学基金(41174004)
中国地震局地震行业科研专项(200708030)
中国地震局地震预测研究所基本科研业务费(2012IES010300)
关键词
华北地区
GPS
高斯加权
主应变率
剪切应变率
north China
GPS
Gaussian distance weighting
principle strain rate
shear strain rate
