基于GPS观测数据的汶川地震断层形变反演分析
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摘要
通过高精度数据处理方法获取了2008年5月12日汶川地震(Mw=8.0)可靠的同震形变位移,较大形变主要在汶川、青川和北川县,其中最大同震形变不在震源处,而在北川县,水平方向达到2.3m,垂向为0.7m。并进一步采用分布滑动模型,利用弹性半空间均匀位错理论反演得到同震断层滑动分布。研究结果表明,不约束断层滑动特性的反演结果显示汶川地震断层不仅仅是右旋、逆断层,还伴随着少许左旋走滑及正断层变化。其地震矩张量为2.38X1021N.M,基于反演的断层滑动分布正演的区域同震形变场主要变形区域分别在都江堰—汶川县,北川县,青川县等一带,地表最大变形达到东方向4.5m,北方向0.8m,具有极强的右旋走势,均与野外地质调查结果相符合。
The May 12th 2008 Wenchuan earthquake (Mw=8.0) caused many people death and economic lost in Sichuan Province. The surface observation data were rapidly obtained using GPS technology by the State Bureau of Surveying and Mapping (SBSM) and China Earthquake Administration (CEA) after the earthquake broking. In this paper, the reliable co-seismic deformation field is derived from GPS measurements using the highly precise data processing method. The larger deformations are in Wenchuan, Qingchuan and Beichuan Counties rather in the epicenter, while the largest magnitude is up to 2.3m in the horizontal and 0.7m in the vertical direction in Beichuan. The co-seismic fault slip distributions are further inverted using the elastic half-space homogeneous model with distributed slip model. The inversion results show that the non-constrained fault slip is most according with the GPS observed co-seismic deformation and the seismic fault is not only right-lateral and thrust slip, but also with a little left-lateral slip and normal slip slide. The moment tensor is about 2.38X1021N·M and the main forwardly-inverted co-seismic deformations are in Dujianyan-Wenchuan county and also in Beichuan, Qingchuan areas at the greatest deformation of about 4.5m in the east direction and 0.8m in the north direction with a strongly right-lateral characteristic, which are almost consistent with the wide geological survey results.
The May 12th 2008 Wenchuan earthquake (Mw=8.0) caused many people death and economic lost in Sichuan Province. The surface observation data were rapidly obtained using GPS technology by the State Bureau of Surveying and Mapping (SBSM) and China Earthquake Administration (CEA) after the earthquake broking. In this paper, the reliable co-seismic deformation field is derived from GPS measurements using the highly precise data processing method. The larger deformations are in Wenchuan, Qingchuan and Beichuan Counties rather in the epicenter, while the largest magnitude is up to 2.3m in the horizontal and 0.7m in the vertical direction in Beichuan. The co-seismic fault slip distributions are further inverted using the elastic half-space homogeneous model with distributed slip model. The inversion results show that the non-constrained fault slip is most according with the GPS observed co-seismic deformation and the seismic fault is not only right-lateral and thrust slip, but also with a little left-lateral slip and normal slip slide. The moment tensor is about 2.38X1021N·M and the main forwardly-inverted co-seismic deformations are in Dujianyan-Wenchuan county and also in Beichuan, Qingchuan areas at the greatest deformation of about 4.5m in the east direction and 0.8m in the north direction with a strongly right-lateral characteristic, which are almost consistent with the wide geological survey results.
引文
[1]TENGJi-wen,BAI Deng-hai,YANG Hui,et al.Deep Processes and Dynamic Responses Associated with the Wenchuan Ms8.0Earthquake of2008[J].Chinese Journal of Geophysics,2008,51(5):1385-1402.(滕吉文,白登海,杨辉,等.2008汶川Ms8.0地震发生的深层过程和动力学响应[J].地球物理学报,2008,51(5):1385-1402.)
[2]WANG Wei-min,ZHAO Lian-feng,LI Juan,et al.Rup-ture Process of the Ms8.0Wenchuan Earthquake of Si-chuan,China[J].Chinese Journal of Geophysics,2008,51(5):1403-1410.(王卫民,赵连锋,李娟,等.四川汶川Ms8.0级地震震源过程[J].地球物理学报,2008,51(5):1411-1421.)
[3]SEGALL P,DAVIS J L.GPS Applications for Geodynam-ics and Earthquake Studies[J].Annu Rev Earth Planet Sci,1997,25,301-336.
[4]BANERJEE P,POLLITZ F F,et al.The Size and Dura-tion of the Sumatra-Andaman Earthquake from Far-field Static Offsets[J].Science,2005,308(5720):1769-1772.
[5]YOSHIOKA S.Coseismic Slip Distribution of the1999Chi-Chi,Tai wan,Earthquake Deduced fromInversion Analysis of GPS Data[J].B Seismol Soc Am,2001,91(5):1182-1189.
[6]WAN Yong-ge,SHEN Zhen-kang,WANG Min,et al.Coseismic Slip Distribution of the2001Kunlun Mountain Pass West Earthquake Constrained Using GPS and InSAR Data[J].Chinese Journal of Geophysics,2008,5l(4):1074-1084.(万永革,沈正康,王敏,等.根据GPS和In-sAR数据反演2001年昆仑山口西地震同震破裂分布[J].地球物理学报,2008,5l(4):1074-1084)
[7]LI Zhi-cai,XUCai-jun,ZHANG Peng,et al.The Co-seis-mic DeformationInversion Analysis due to Different Seismic Fault Based on Crust Layering[J].Geomatics and Informa-tion Science of Wuhan University,2008,33(3):229-232.(李志才,许才军,张鹏,等.基于地壳分层的地震断层同震变形反演分析[J].武汉大学学报信息科学版,2008,33(3):229-232.)
[8]LI Zhi-cai,XU Cai-jun,ZHAO Shao-rong,et al.Study of Difference among Different Earth’s Structure Modelsin Co-seismic Deformation Analysis[J].Journal of Geodesy and Geodynamics,2005,25(3):39-44.(李志才,许才军,赵少荣,等.同震变形分析中不同地球结构模型差异性研究[J].大地测量与地球动力学,2005,25(3):39-44.)
[9]LI Zhi-cai.Research on the Geodesy Inversion Mode Con-sidering the Earth Structure and Its Application[D].Wu-han:Wuhan University,2005.(李志才.顾及地球结构的大地测量反演模式与应用[D].武汉:武汉大学,2005.)
[10]SHEN Z K,ZHAO C,LI Y.et al.Contemporary Crus-tal Deformationin East Aisa Constrained by Global Posi-tioning System Measurements[J].J Geophys Res,2000,105:(B3):5721-5734.
[11]OKADA Y.Surface Deformation Caused by Shear and Tensile Faults in a Half-space[J].Bull Seismol Soc Am,1985,75(4):1135-1154.
[12]OKADA Y.Internal Deformation due to Shear and Ten-sile Faults in a Half Space[J].Bull SeismSoc Am,1992,82:1018-1040.
[13]POLLITZ F F.Postseismic Relaxation Theory on the Spherical Earth[J].Bull Seismol Soc Am,1992,82:422-453.
[14]POLLITZ F F.Coseismic Deformation from Earthquake Faulting on a Layered Spherical Earth[J].Geophys J Int,1996,125:1-14.
[15]SUN W,OKUBO S.Surface Potential and Gravity Chan-ges due to Internal Dislocations in a Spherical Earth,1,Theory for a Point Dislocation[J].Geophys J Int,1993,114:569-592.
[16]SUN W,OKUBO S.Effects of the Earth’s Spherical Curvature and Radial Heterogeneity in Dislocation Studiesfor a Point Dislocation[J].Geophys Res Lett,2002,29(12):1605-1615.
[17]SUN W,OKUBO S,VANICEK P.Global Displacement Caused by Dislocations in a Realistic Earth Model[J].J Geophys Res,1996,101:8561-8577.
[18]HARRIS R A,SEGALL P.Detection of a Locked Zone at Depth on the Parkfield,California,Segment of the San Andreas Fault[J].J Geophys Res,1987,2(B8):7945-7962.
[19]STARK P B,PARKER R L.Bounded Variable Least Squares:an Algorithm and Applications[J].Computa-tional Statistics,1995,10:129-141.
[20]WANG Hua.Co-seismic and Inter-seismic Deformationin Hi malayan-Tibet from InSAR[D].Wuhan:Wuhan Uni-versity,2007.(王华.利用InSAR研究青藏高原地区若干同震与震间形变[D].武汉:武汉大学,2007.)
[21]J’ONSSON S,ZEBKER H,SEGALL P,et al.Fault Slip Distribution of the1999Mw7.1Hector Mine,California,Earthquake,Esti mated from Satellite Radar and GPS Measurements[J].Bull Seismol Soc Am,2002,92(4):1377-1389.
[22]ZHANG Pei-zhen,XU Xi-wei,WEN Xue-ze,et al.Slip Rates and Recurrence Intervals of the Longmen Shan Ac-tive Fault Zone,and Tectonic I mplications for the Mecha-nism of the May12Wenchuan Earthquake,2008,Si-chuan,China[J].Chinese Journal of Geophysics,2008,51(4):1066-1073.(张培震,徐锡伟,闻学泽,等.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):1066-1073.)
[23]ZHOU Wen,QI Xu-shi,LI Zhong-dong,et al.The Re-search of Modified Plan on Jurassic Gas Pool Ground Stress and Gas Sand Pressure Crack in West Area[R].Chengdu:Southwest Company of China Sinopec,2003.(周文,齐翊时,李仲东,等,川西坳陷侏罗系气藏地应力与气层压裂改造方案研究[R].成都:中国石化西南分公司,2003.)
[2]WANG Wei-min,ZHAO Lian-feng,LI Juan,et al.Rup-ture Process of the Ms8.0Wenchuan Earthquake of Si-chuan,China[J].Chinese Journal of Geophysics,2008,51(5):1403-1410.(王卫民,赵连锋,李娟,等.四川汶川Ms8.0级地震震源过程[J].地球物理学报,2008,51(5):1411-1421.)
[3]SEGALL P,DAVIS J L.GPS Applications for Geodynam-ics and Earthquake Studies[J].Annu Rev Earth Planet Sci,1997,25,301-336.
[4]BANERJEE P,POLLITZ F F,et al.The Size and Dura-tion of the Sumatra-Andaman Earthquake from Far-field Static Offsets[J].Science,2005,308(5720):1769-1772.
[5]YOSHIOKA S.Coseismic Slip Distribution of the1999Chi-Chi,Tai wan,Earthquake Deduced fromInversion Analysis of GPS Data[J].B Seismol Soc Am,2001,91(5):1182-1189.
[6]WAN Yong-ge,SHEN Zhen-kang,WANG Min,et al.Coseismic Slip Distribution of the2001Kunlun Mountain Pass West Earthquake Constrained Using GPS and InSAR Data[J].Chinese Journal of Geophysics,2008,5l(4):1074-1084.(万永革,沈正康,王敏,等.根据GPS和In-sAR数据反演2001年昆仑山口西地震同震破裂分布[J].地球物理学报,2008,5l(4):1074-1084)
[7]LI Zhi-cai,XUCai-jun,ZHANG Peng,et al.The Co-seis-mic DeformationInversion Analysis due to Different Seismic Fault Based on Crust Layering[J].Geomatics and Informa-tion Science of Wuhan University,2008,33(3):229-232.(李志才,许才军,张鹏,等.基于地壳分层的地震断层同震变形反演分析[J].武汉大学学报信息科学版,2008,33(3):229-232.)
[8]LI Zhi-cai,XU Cai-jun,ZHAO Shao-rong,et al.Study of Difference among Different Earth’s Structure Modelsin Co-seismic Deformation Analysis[J].Journal of Geodesy and Geodynamics,2005,25(3):39-44.(李志才,许才军,赵少荣,等.同震变形分析中不同地球结构模型差异性研究[J].大地测量与地球动力学,2005,25(3):39-44.)
[9]LI Zhi-cai.Research on the Geodesy Inversion Mode Con-sidering the Earth Structure and Its Application[D].Wu-han:Wuhan University,2005.(李志才.顾及地球结构的大地测量反演模式与应用[D].武汉:武汉大学,2005.)
[10]SHEN Z K,ZHAO C,LI Y.et al.Contemporary Crus-tal Deformationin East Aisa Constrained by Global Posi-tioning System Measurements[J].J Geophys Res,2000,105:(B3):5721-5734.
[11]OKADA Y.Surface Deformation Caused by Shear and Tensile Faults in a Half-space[J].Bull Seismol Soc Am,1985,75(4):1135-1154.
[12]OKADA Y.Internal Deformation due to Shear and Ten-sile Faults in a Half Space[J].Bull SeismSoc Am,1992,82:1018-1040.
[13]POLLITZ F F.Postseismic Relaxation Theory on the Spherical Earth[J].Bull Seismol Soc Am,1992,82:422-453.
[14]POLLITZ F F.Coseismic Deformation from Earthquake Faulting on a Layered Spherical Earth[J].Geophys J Int,1996,125:1-14.
[15]SUN W,OKUBO S.Surface Potential and Gravity Chan-ges due to Internal Dislocations in a Spherical Earth,1,Theory for a Point Dislocation[J].Geophys J Int,1993,114:569-592.
[16]SUN W,OKUBO S.Effects of the Earth’s Spherical Curvature and Radial Heterogeneity in Dislocation Studiesfor a Point Dislocation[J].Geophys Res Lett,2002,29(12):1605-1615.
[17]SUN W,OKUBO S,VANICEK P.Global Displacement Caused by Dislocations in a Realistic Earth Model[J].J Geophys Res,1996,101:8561-8577.
[18]HARRIS R A,SEGALL P.Detection of a Locked Zone at Depth on the Parkfield,California,Segment of the San Andreas Fault[J].J Geophys Res,1987,2(B8):7945-7962.
[19]STARK P B,PARKER R L.Bounded Variable Least Squares:an Algorithm and Applications[J].Computa-tional Statistics,1995,10:129-141.
[20]WANG Hua.Co-seismic and Inter-seismic Deformationin Hi malayan-Tibet from InSAR[D].Wuhan:Wuhan Uni-versity,2007.(王华.利用InSAR研究青藏高原地区若干同震与震间形变[D].武汉:武汉大学,2007.)
[21]J’ONSSON S,ZEBKER H,SEGALL P,et al.Fault Slip Distribution of the1999Mw7.1Hector Mine,California,Earthquake,Esti mated from Satellite Radar and GPS Measurements[J].Bull Seismol Soc Am,2002,92(4):1377-1389.
[22]ZHANG Pei-zhen,XU Xi-wei,WEN Xue-ze,et al.Slip Rates and Recurrence Intervals of the Longmen Shan Ac-tive Fault Zone,and Tectonic I mplications for the Mecha-nism of the May12Wenchuan Earthquake,2008,Si-chuan,China[J].Chinese Journal of Geophysics,2008,51(4):1066-1073.(张培震,徐锡伟,闻学泽,等.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):1066-1073.)
[23]ZHOU Wen,QI Xu-shi,LI Zhong-dong,et al.The Re-search of Modified Plan on Jurassic Gas Pool Ground Stress and Gas Sand Pressure Crack in West Area[R].Chengdu:Southwest Company of China Sinopec,2003.(周文,齐翊时,李仲东,等,川西坳陷侏罗系气藏地应力与气层压裂改造方案研究[R].成都:中国石化西南分公司,2003.)
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