利用GPS观测分析青藏高原东缘应变特征
|
摘要
根据青藏高原东缘2004~2007年的GPS观测资料,通过多面函数法建立青藏高原东缘地壳水平运动速度场模型,给出球面坐标系下的视应变场。对照该区同期发生的地震活动,讨论了水平运动、应变场空间分布与强震和区域构造变形的关系。结果表明,松潘块体东西向地壳缩短显著,川滇块体以左旋剪切变形和顺时针转动为主。地应变特征表明,2008年汶川地震前龙门山地区为面应变能次高值区,呈面压特性,应变快速积累,龙门山断裂带中段震前处于闭锁状态。鲜水河断裂带西段南北地壳呈北东-南西向挤压缩短,东段两侧呈北西-南东向压缩。川滇菱形块体为应变能和面应变率梯度高值区,金沙江西部的应变能次高值区与羌塘块体的构造应力作用有关。
The displacement model of surface horizontal motion is calculated by using a multi-surface function based on the GPS data from the eastern Tibetan plateau from 2004 to 2007,and the strain field on the spherical coordinates is given.Through comparison of earthquakes that occurred in the observation periods and the fault distribution in the area,the relationship among horizontal motion,strain space distribution,strong earthquakes and regional tectonic deformation is discussed.The results indicated that EW trending crustal shortening is remarkable in Songpan block and the deformation in Sichuan-Yunnan block is dominated by left-lateral shear and rotation.Furthermore,before the Wenchuan earthquake,the Longmenshan fault displayed a secondary high value of strain energy,the surface strain showed a pressure property,with the strain increasing rapidly,and the middle segment of the Longmenshan fault has been locked.The crustal zone in the western segment of the Xianshuihe fault shows NE-SE shortening and in the eastern segment the crustal displays NW-SE shortening.Sichuan-Yunan diamond block is an area with high value of strain energy and surface strain gradient,the western region of Jinshajiang is dominated by strong strain energy,which is associated with the tectonic stress of Qiangtang block.
The displacement model of surface horizontal motion is calculated by using a multi-surface function based on the GPS data from the eastern Tibetan plateau from 2004 to 2007,and the strain field on the spherical coordinates is given.Through comparison of earthquakes that occurred in the observation periods and the fault distribution in the area,the relationship among horizontal motion,strain space distribution,strong earthquakes and regional tectonic deformation is discussed.The results indicated that EW trending crustal shortening is remarkable in Songpan block and the deformation in Sichuan-Yunnan block is dominated by left-lateral shear and rotation.Furthermore,before the Wenchuan earthquake,the Longmenshan fault displayed a secondary high value of strain energy,the surface strain showed a pressure property,with the strain increasing rapidly,and the middle segment of the Longmenshan fault has been locked.The crustal zone in the western segment of the Xianshuihe fault shows NE-SE shortening and in the eastern segment the crustal displays NW-SE shortening.Sichuan-Yunan diamond block is an area with high value of strain energy and surface strain gradient,the western region of Jinshajiang is dominated by strong strain energy,which is associated with the tectonic stress of Qiangtang block.
引文
[1]李延兴,杨国华,李智,等.中国大陆活动地块的运动与应变状态[J].中国科学:D辑,2003,33(B04):65-81(Li Yanxing,Yang Guohua,Li Zhi,et al.Movement and Strain Conditions of Active Blocks in the Chinese Mainland[J].Science in China Series D:Earth Sciences,2003,33(B04):65-81)
[2]朱守彪,蔡永恩,石耀霖.青藏高原及邻区现今地应变率场的计算及其结果的地球动力学意义[J].地球物理学报,2005,48(5):1 053-1 061(Zhu Shoubiao,Cai Yongen,Shi Yaolin.Computation of the Present-Day Strain Rate Field of the Qinghai-Tibetan Plateau and Its Geodynamic Implications[J].Chinese J Geophys,2005,48(5):1 053-1 061)
[3]江在森,杨国华,王敏,等.中国大陆地壳运动与强震关系研究[J].大地测量与地球动力学,2006,26(3):1-9(Jiang Zaisen,Yang Guohua,Wang Min,et al.On Crustal Movement in China Continent and Its Relationship with Strong Earthquakes[J].Journal of Geodesy and Geodynamics,2006,26(3):1-9)
[4]张永志,赵大江,王卫东,等.利用GPS观测研究中国西北地区应变能变化特征[J].大地测量与地球动力学,2007,27(3):1-5(Zhang Yongzhi,Zhao Dajiang,Wang Weidong,et al.Characteristic of Strain Energy Variation from GPS Data in Northwestern China[J].Journal of Geodesy and Geodynamics,2007,27(3):1-5)
[5]张希,江在森,王琪,等.川滇地区地壳水平运动特征与强震关系研究[J].大地测量与地球动力学,2003,23(3):35-41(Zhang Xi,Jiang Zaisen,Wang Qi,et al.Recent Crust Motion Features in Sichuan-Yunnan and Their Relationship to Strong Earthquakes[J].Journal of Geodesy and Geodynamics,2003,23(3):35-41)
[6]吕志鹏,伍吉仓,孟国杰,等.青藏高原东缘地应变空间分布特征分析[J].大地测量与地球动力学,2014,34(1):19-23(LüZhipeng,Wu Jicang,Meng Guojie,et al.Analysis of Spatial Distribution of Strain at Eastern Margin of Tibetan Plateau[J].Journal of Geodesy and Geodynamics,2014,34(1):19-23)
[7]张晶,武艳强,刘琦,等.GPS水平形变面应变率梯度与强震危险区关系探讨[J].地震学报,2013,35(6):828-835(Zhang Jing,Wu Yanqiang,Liu Qi,et al.Study on the Relationship between Plane Strain Rate Gradient of GPS Horizontal Deformation and Strong Earthquake Risk Area[J].Acta Seismologica Sinica,2013,35(6):828-835)
[8]赖锡安,黄立人,徐菊生.中国大陆现今地壳运动[M].北京:地震出版社,2004(Lai Xi’an,Huang Liren,Xu Jusheng,et al.Present-Day Crustal Movement in China Constrained[M].Beijing:Seismic Press,2004)
[9]黄立人,陶本藻,赵承坤.多面函数拟合在地壳垂直运动研究中的应用[J].测绘学报,1993,22(1):25-31(Huang Liren,Tao Benzao,Zhao Chengkun.The Application of Fitting Method of Multi-quadric Functions in Research on Crustal Vertical Movement[J].Acta Geodaetica et Cartographic Sinica,1993,22(1):25-31)
[10]吴啸龙,杨志强,武继峰,等.基于多面函数法的青藏高原应变特征分析[J].大地测量与地球动力学,2013,33(4):17-21(Wu Xiaolong,Yang Zhiqiang,Wu Jifeng,et al.Analysis on Qinghai-Tibet Plateau Strain Field Based on Multisurface Function[J].Journal of Geodesy and Geodynamics,2013,33(4):17-21)
[11]石耀霖,朱守彪.用GPS位移资料计算应变方法的讨论[J].大地测量与地球动力学,2006,26(1):1-8(Shi Yaolin,Zhu Shoubiao.Discussion on Method of Calculating Strain with GPS Displacement Data[J].Journal of Geodesy and Geodynamics,2006,26(1):1-8)
[12]武艳强,江在森,杨国华,等.利用最小二乘配置在球面上整体解算GPS应变场的方法及应用[J].地球物理学报,2009,52(7):1 707-1 711(Wu Yanqiang,Jiang Zaisen,Yang Guohua,et al.The Application and Method of GPS Strain Calculation in Whole Mode Using Least-Squares Collocation in Sphere Surface[J].Chinese J Geophys,2009,52(7):1 707-1 711)
[13]张培震,徐锡伟,闻学泽.2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因[J].地球物理学报,2008,51(4):1 066-1 073(Zhang Peizhen,Xu Xiwei,Wen Xueze,et al.Slip Rates and Recurrence Intervals of the Longmenshan Active Fault Zone,and Tectonic Implications for the Mechanism of the May 12 Wenchuan Earthquake,2008,Sichuan,China[J].Chinese J Geophys,2008,51(4):1 066-1 073)
[14]王卫民,赵连锋,李娟,等.四川汶川8.0级地震震源过程[J].地球物理学报,2008,51(5):1 403-1 410(Wang Weimin,Zhao Lianfeng,Li Juan,et al.Rupture Process of the Ms 8.0 Wenchuan Earthquake of Sichuan,China[J].Chinese J Geophys,2008,51(5):1 403-1 410)
[15]朱守彪,石耀霖.广义应变化方法及其在川滇地区地应变率场计算中的应用[J].中国科学院研究生院学报,2005,22(3):292-302(Zhu Shoubiao,Shi Yaolin.General Strain Rosette Method and Its Application to the Computation of Geo-strain Rate in Chinese Sichuan-Yunnan Area[J].Journal of the Graduate School of the Chinese Academy of Science,2005,22(3):292-302)
[16]张希,张四新,王双绪,等.川滇地区近期地壳运动的应变积累[J].大地测量与地球动力学,2007,27(4):8-15(Zhang Xi,Zhang Sixin,Wang Shuangxu,et al.On Strain Accumulation of Recent Crust Movement in Sichuan-Yunnan Area[J].Journal of Geodesy and Geodynamics,2007,27(4):8-15)
[17]杜方,闻学泽,张培震,等.2008年汶川8.0级地震前横跨龙门山断裂带的震间形变[J].地球物理学报,2009,52(11):2 729-2 738(Du Fang,Wen Xueze,Zhang Peizhen,et al.Interseismic Deformation Across the Longmenshan Fault Zone before the Ms 8.0 Wenchuan Earthquake[J].Chinese J Geophys,2009,52(11):2 729-2 738)
[2]朱守彪,蔡永恩,石耀霖.青藏高原及邻区现今地应变率场的计算及其结果的地球动力学意义[J].地球物理学报,2005,48(5):1 053-1 061(Zhu Shoubiao,Cai Yongen,Shi Yaolin.Computation of the Present-Day Strain Rate Field of the Qinghai-Tibetan Plateau and Its Geodynamic Implications[J].Chinese J Geophys,2005,48(5):1 053-1 061)
[3]江在森,杨国华,王敏,等.中国大陆地壳运动与强震关系研究[J].大地测量与地球动力学,2006,26(3):1-9(Jiang Zaisen,Yang Guohua,Wang Min,et al.On Crustal Movement in China Continent and Its Relationship with Strong Earthquakes[J].Journal of Geodesy and Geodynamics,2006,26(3):1-9)
[4]张永志,赵大江,王卫东,等.利用GPS观测研究中国西北地区应变能变化特征[J].大地测量与地球动力学,2007,27(3):1-5(Zhang Yongzhi,Zhao Dajiang,Wang Weidong,et al.Characteristic of Strain Energy Variation from GPS Data in Northwestern China[J].Journal of Geodesy and Geodynamics,2007,27(3):1-5)
[5]张希,江在森,王琪,等.川滇地区地壳水平运动特征与强震关系研究[J].大地测量与地球动力学,2003,23(3):35-41(Zhang Xi,Jiang Zaisen,Wang Qi,et al.Recent Crust Motion Features in Sichuan-Yunnan and Their Relationship to Strong Earthquakes[J].Journal of Geodesy and Geodynamics,2003,23(3):35-41)
[6]吕志鹏,伍吉仓,孟国杰,等.青藏高原东缘地应变空间分布特征分析[J].大地测量与地球动力学,2014,34(1):19-23(LüZhipeng,Wu Jicang,Meng Guojie,et al.Analysis of Spatial Distribution of Strain at Eastern Margin of Tibetan Plateau[J].Journal of Geodesy and Geodynamics,2014,34(1):19-23)
[7]张晶,武艳强,刘琦,等.GPS水平形变面应变率梯度与强震危险区关系探讨[J].地震学报,2013,35(6):828-835(Zhang Jing,Wu Yanqiang,Liu Qi,et al.Study on the Relationship between Plane Strain Rate Gradient of GPS Horizontal Deformation and Strong Earthquake Risk Area[J].Acta Seismologica Sinica,2013,35(6):828-835)
[8]赖锡安,黄立人,徐菊生.中国大陆现今地壳运动[M].北京:地震出版社,2004(Lai Xi’an,Huang Liren,Xu Jusheng,et al.Present-Day Crustal Movement in China Constrained[M].Beijing:Seismic Press,2004)
[9]黄立人,陶本藻,赵承坤.多面函数拟合在地壳垂直运动研究中的应用[J].测绘学报,1993,22(1):25-31(Huang Liren,Tao Benzao,Zhao Chengkun.The Application of Fitting Method of Multi-quadric Functions in Research on Crustal Vertical Movement[J].Acta Geodaetica et Cartographic Sinica,1993,22(1):25-31)
[10]吴啸龙,杨志强,武继峰,等.基于多面函数法的青藏高原应变特征分析[J].大地测量与地球动力学,2013,33(4):17-21(Wu Xiaolong,Yang Zhiqiang,Wu Jifeng,et al.Analysis on Qinghai-Tibet Plateau Strain Field Based on Multisurface Function[J].Journal of Geodesy and Geodynamics,2013,33(4):17-21)
[11]石耀霖,朱守彪.用GPS位移资料计算应变方法的讨论[J].大地测量与地球动力学,2006,26(1):1-8(Shi Yaolin,Zhu Shoubiao.Discussion on Method of Calculating Strain with GPS Displacement Data[J].Journal of Geodesy and Geodynamics,2006,26(1):1-8)
[12]武艳强,江在森,杨国华,等.利用最小二乘配置在球面上整体解算GPS应变场的方法及应用[J].地球物理学报,2009,52(7):1 707-1 711(Wu Yanqiang,Jiang Zaisen,Yang Guohua,et al.The Application and Method of GPS Strain Calculation in Whole Mode Using Least-Squares Collocation in Sphere Surface[J].Chinese J Geophys,2009,52(7):1 707-1 711)
[13]张培震,徐锡伟,闻学泽.2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因[J].地球物理学报,2008,51(4):1 066-1 073(Zhang Peizhen,Xu Xiwei,Wen Xueze,et al.Slip Rates and Recurrence Intervals of the Longmenshan Active Fault Zone,and Tectonic Implications for the Mechanism of the May 12 Wenchuan Earthquake,2008,Sichuan,China[J].Chinese J Geophys,2008,51(4):1 066-1 073)
[14]王卫民,赵连锋,李娟,等.四川汶川8.0级地震震源过程[J].地球物理学报,2008,51(5):1 403-1 410(Wang Weimin,Zhao Lianfeng,Li Juan,et al.Rupture Process of the Ms 8.0 Wenchuan Earthquake of Sichuan,China[J].Chinese J Geophys,2008,51(5):1 403-1 410)
[15]朱守彪,石耀霖.广义应变化方法及其在川滇地区地应变率场计算中的应用[J].中国科学院研究生院学报,2005,22(3):292-302(Zhu Shoubiao,Shi Yaolin.General Strain Rosette Method and Its Application to the Computation of Geo-strain Rate in Chinese Sichuan-Yunnan Area[J].Journal of the Graduate School of the Chinese Academy of Science,2005,22(3):292-302)
[16]张希,张四新,王双绪,等.川滇地区近期地壳运动的应变积累[J].大地测量与地球动力学,2007,27(4):8-15(Zhang Xi,Zhang Sixin,Wang Shuangxu,et al.On Strain Accumulation of Recent Crust Movement in Sichuan-Yunnan Area[J].Journal of Geodesy and Geodynamics,2007,27(4):8-15)
[17]杜方,闻学泽,张培震,等.2008年汶川8.0级地震前横跨龙门山断裂带的震间形变[J].地球物理学报,2009,52(11):2 729-2 738(Du Fang,Wen Xueze,Zhang Peizhen,et al.Interseismic Deformation Across the Longmenshan Fault Zone before the Ms 8.0 Wenchuan Earthquake[J].Chinese J Geophys,2009,52(11):2 729-2 738)
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