南北地震带北段近期地壳变形特征研究
|
摘要
利用1999～2007期和2007～2009期GPS速度场、应变率场、断层滑动速率和GPS速度剖面等数据,识别出了南北地震带北段主要断裂带及其邻近地区的显著变形差异。结果表明,庄浪河断裂带左旋剪切变形明显增强,祁连地块北边界左旋剪切变形明显增强;2007～2009期六盘山断裂和海原断裂带挤压变形也有所增强,但量值不大。上述特征表明,庄浪河以东地区存在较高的应变积累背景。
Based on the analysis of fitting residual errors of GPS velocity,the errors of deformation parameters,and the applicability of block model,we use GPS velocity fields,strain rate fields,slipping rate of faults and GPS profile results from 1999-2007 and from 2007-2009 to identify the deformation difference of principle faults on the north section of North-South Seismic Zone.The results show that the laevorotation deformation of Zhuanglanghe Fault has increased,which the dextrorotation deformation rate calculated from Eulerian model is about 1.5±0.3 mm·a-1 in the period 1999-2007,and the laevorotation deformation rate is about 5.3±0.4 mm·a-1 in the period 2007-2009.On the other hand,the laevorotation slipping rate of north boundary of Qilian block has increased from 2.5±0.2 mm·a-1 to 7.0±0.2 mm·a-1 in these two periods.Otherwise,the extrusion deformation of Liupanshan and Haiyuan Faults has strengthened too,but the deformation magnitude is not big.These above deformation characteristics illustrate that the region of east side of Zhuanglanghe Fault has accumulated high strain energy.
Based on the analysis of fitting residual errors of GPS velocity,the errors of deformation parameters,and the applicability of block model,we use GPS velocity fields,strain rate fields,slipping rate of faults and GPS profile results from 1999-2007 and from 2007-2009 to identify the deformation difference of principle faults on the north section of North-South Seismic Zone.The results show that the laevorotation deformation of Zhuanglanghe Fault has increased,which the dextrorotation deformation rate calculated from Eulerian model is about 1.5±0.3 mm·a-1 in the period 1999-2007,and the laevorotation deformation rate is about 5.3±0.4 mm·a-1 in the period 2007-2009.On the other hand,the laevorotation slipping rate of north boundary of Qilian block has increased from 2.5±0.2 mm·a-1 to 7.0±0.2 mm·a-1 in these two periods.Otherwise,the extrusion deformation of Liupanshan and Haiyuan Faults has strengthened too,but the deformation magnitude is not big.These above deformation characteristics illustrate that the region of east side of Zhuanglanghe Fault has accumulated high strain energy.
引文
[1]刘经南,施闯,姚宜斌,等.多面函数拟合法及其在建立中国地壳平面运动速度场模型中的应用研究[J].武汉大学学报.信息科学版,2001,26(6):500-503
[2]刘经南,姚宜斌,施闯.中国地壳运动整体速度场模型的建立方法研究.[J].武汉大学学报.信息科学版,2002,27(4):331-336
[3]江在森,方颖,武艳强,等.汶川8.0级地震前区域地壳运动与变形动态过程[J].地球物理学报,2009,52(2):505-518
[4]“中国地壳运动观测网络”项目组.GPS测定的2008年汶川Ms8.0级地震的同震位移场[J].中国科学D辑,2008,38(10):195-106
[5]江在森,丁平,王双绪,等.中国西部大地形变监测与地震预测[M].北京:地震出版社,2001
[6]李延兴,李智,张静华,等.中国大陆及周边地区的水平应变场[J].地球物理学报,2004,47(2):222-231
[7]张希,张晓亮,张四新,等.青藏块体东北缘近期GPS水平运动特征与汶川大震影响[J].地震研究,2010,33(4):265-268
[2]刘经南,姚宜斌,施闯.中国地壳运动整体速度场模型的建立方法研究.[J].武汉大学学报.信息科学版,2002,27(4):331-336
[3]江在森,方颖,武艳强,等.汶川8.0级地震前区域地壳运动与变形动态过程[J].地球物理学报,2009,52(2):505-518
[4]“中国地壳运动观测网络”项目组.GPS测定的2008年汶川Ms8.0级地震的同震位移场[J].中国科学D辑,2008,38(10):195-106
[5]江在森,丁平,王双绪,等.中国西部大地形变监测与地震预测[M].北京:地震出版社,2001
[6]李延兴,李智,张静华,等.中国大陆及周边地区的水平应变场[J].地球物理学报,2004,47(2):222-231
[7]张希,张晓亮,张四新,等.青藏块体东北缘近期GPS水平运动特征与汶川大震影响[J].地震研究,2010,33(4):265-268
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心