四川芦山地震区域构造环境与构造应力场特征
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摘要
2013年4月20日四川省雅安市芦山县发生Ms7.0级地震,这是继汶川地震后发生在龙门山断裂带上的又一次强震。在介绍芦山地震的基本特征及发震构造环境基础上,利用区域内172个震源机制解资料对区域构造应力场进行了计算,特别对龙门山应力区内各类应力数据的最大主应力方向进行了分析。结果表明:龙门山应力区目前处于近东西向的挤压构造应力环境中;区域最大主应力方向在横向上从巴颜喀拉块体的北东—南西向到龙门山块体的近东西向,再到华南块体的北西西—南东东向,表现为顺时针方向的旋转;区域最大主应力在纵向上从柴达木—秦岭块体的北东东—南西西向到龙门山块体的近东西向,再到川滇块体的北西—南东向,亦表现为顺时针方向的旋转;应力方向在不同块体间的转变,反映了青藏高原东缘巴颜喀拉块体在进行南东向水平运动挤压龙门山地块时,由于受到华南地块特别是四川盆地的强烈阻挡,导致龙门山推覆构造带表现为明显的地壳缩短和山体隆升。
In April 20,2013,a Ms7.0 earthquake hitted Lushan county of Ya'an city,Sichuan province,which was another strong earthquake on Longmenshan foreland thrust zone after Wenchuan earthquake.Basic characteristics and seismogenic tectonic setting of Lushan earthquake were introduced,and regional tectonic stress field was calculated by 172 focal mechanism solutions,especially the directions of maximum principal stress were analyzed based on five different kinds of stress data in Longmenshan stress region.The results indicate that the direction of maximum principal stress in Longmenshan stress region is nearly in EW-direction compressional tectonic setting at present;the direction of maximum principal stress is from NE-SW-direction in Bayan Har block to nearly EW-direction in Longmenshan block,and then to NWW-SEE-direction in South China block,showing clockwise rotation from west to east in spatial distribution;the direction of maximum principal stress is from NEE-SWW-direction in Qaidam-Qinling block to nearly EW-direction in Longmenshan block,and then to NW-SE-direction in Chuandian block,also showing clockwise rotation from south to north in spatialdistribution.Transition of stress direction among different blocks indicates that Bayan Har block in the eastern margin of Qinghai-Tibet Plateau moves to the south-east and pushes the Longmenshan block because of the strong stop of Sichuan Basin in South China block,and results in obvious crustal shortening and mountain uplift of Longmenshan foreland thrust zone.
In April 20,2013,a Ms7.0 earthquake hitted Lushan county of Ya'an city,Sichuan province,which was another strong earthquake on Longmenshan foreland thrust zone after Wenchuan earthquake.Basic characteristics and seismogenic tectonic setting of Lushan earthquake were introduced,and regional tectonic stress field was calculated by 172 focal mechanism solutions,especially the directions of maximum principal stress were analyzed based on five different kinds of stress data in Longmenshan stress region.The results indicate that the direction of maximum principal stress in Longmenshan stress region is nearly in EW-direction compressional tectonic setting at present;the direction of maximum principal stress is from NE-SW-direction in Bayan Har block to nearly EW-direction in Longmenshan block,and then to NWW-SEE-direction in South China block,showing clockwise rotation from west to east in spatial distribution;the direction of maximum principal stress is from NEE-SWW-direction in Qaidam-Qinling block to nearly EW-direction in Longmenshan block,and then to NW-SE-direction in Chuandian block,also showing clockwise rotation from south to north in spatialdistribution.Transition of stress direction among different blocks indicates that Bayan Har block in the eastern margin of Qinghai-Tibet Plateau moves to the south-east and pushes the Longmenshan block because of the strong stop of Sichuan Basin in South China block,and results in obvious crustal shortening and mountain uplift of Longmenshan foreland thrust zone.
引文
[1]王卫民,郝金来,姚振兴.2013年4月20日四川芦山地震震源破裂过程反演初步结果[J].地球物理学报,2013,56(4):1412-1417.WANG Wei-min,HAO Jin-lai,YAO Zhen-xing.Pre-liminary Result for Rupture Process of April 20,2013,Lushan Earthquake,Sichuan,China[J].ChineseJournal of Geophysics,2013,56(4):1412-1417.
[2]张勇,许力生,陈运泰.芦山4.20地震破裂过程及其致灾特征初步分析[J].地球物理学报,2013,56(4):1408-1411.ZHANG Yong,XU Li-sheng,CHEN Yun-tai,et al.Rupture Process of the Lushan 4.20Earthquake andPreliminary Analysis on the Disaster-causing Mecha-nism[J].Chinese Journal of Geophysics,2013,56(4):1408-1411.
[3]邓起东,陈社发,赵小麟.龙门山及其邻区的构造和地震活动及动力学[J].地震地质,1994,16(4):389-403.DENG Qi-dong,CHEN She-fa,ZHAO Xiao-lin.Tec-tonics,Seismisity and Dynamics of LongmenshanMountains and Its Adjacent Regions[J].Seismologyand Geology,1994,16(4):389-403.
[4]杨晓平,蒋溥,宋方敏,等.龙门山断裂带南段错断晚更新世以来地层的证据[J].地震地质,1999,21(4):341-345.YANG Xiao-ping,JIANG Pu,SONG Fang-min,et al.The Evidence of the South Longmenshan Fault ZonesCutting Late Quaternary Stratum[J].Seismology andGeology,1999,21(4):341-345.
[5]李勇,周荣军,DENSMORE A L,等.青藏高原东缘龙门山晚新生代走滑-逆冲作用的地貌标志[J].第四纪研究,2006,26(1):40-51.LI Yong,ZHOU Rong-jun,DENSMORE A L,et al.Geomorphic Evidence for the Late Cenozoic Strike-slipping and Thrusting in Longmen Mountain at theEastern Margin of the Tibetan Plateau[J].QuaternarySciences,2006,26(1):40-51.
[6]陈国光,计凤桔,周荣军,等.龙门山断裂带晚第四纪活动性分段的初步研究[J].地震地质,2007,29(3):657-673.CHEN Guo-guang,JI Feng-ju,ZHOU Rong-jun,et al.Primary Research of Activity Segmentation of Long-menshan Fault Zone Since Late Quaternary[J].Seismology and Geology,2007,29(3):657-673.
[7]贾秋鹏,贾东,朱艾斓,等.青藏高原东缘龙门山冲断带与四川盆地的现今构造表现:数字地形和地震活动证据[J].地质科学,2007,42(1):31-44.JIA Qiu-peng,JIA Dong,ZHU Ai-lan,et al.ActiveTectonics in the Longmenshan Thrust Belt to theEastern Qinghai-Tibetan Plateau and Sichuan Basin:Evidence from Topography and Seismicity[J].ChineseJournal of Geology,2007,42(1):31-44.
[8]徐锡伟,闻学泽,叶建青,等.汶川Ms8.0地震地表破裂带及其发震构造[J].地震地质,2008,30(3):597-629.XU Xi-wei,WEN Xue-ze,YE Jian-qing,et al.The Ms8.0Wenchuan Earthquake Surface Ruptures and ItsSeismogenic Structure[J].Seismology and Geology,2008,30(3):597-629.
[9]徐锡伟,陈桂华,于贵华,等.芦山地震发震构造及其与汶川地震关系讨论[J].地学前缘,2013,20(3):11-20.XU Xi-wei,CHEN Gui-hua,YU Gui-hua,et al.Seis-mogenic Structure of Lushan Earthquake and ItsRelationship with Wenchuan Earthquake[J].EarthScience Frontiers,2013,20(3):11-20.
[10]谢富仁,陈群策,崔效锋,等.中国大陆地壳应力环境研究[M].北京:地质出版社,2003.XIE Fu-ren,CHEN Qun-ce,CUI Xiao-feng,et a1.Researchon Continental Crustal Stress Environment in China[M].Beijing:Geological Publishing House,2003.
[11]鄢家全,时振梁,环文林,等.强余震的断层面解特征[J].地震学报,1980,2(4):395-403.YAN Jia-quan,SHI Zhen-Liang,HUAN Wen-Lin,et al.The Characteristics of Fault Plane Solutions of StrongAftershocks[J].Acta Seismologica Sinica,1980,2(4):395-403.
[12]ZHOU H L,LIU H L,KANAMORI H.Source Pro-cesses of Large Earthquakes Along the XianshuiheFault in Southwestern China[J].Bulletin of the Seis-mological Society of America,1983,73(2):537-551.
[13]许忠淮,汪素云,高阿甲,等.我国部分早期震源机制解答的重新测定[J].地震地磁观测与研究,1994,15(5):1-9.XU Zhong-huai,WANG Su-yun,GAO A-jia,et al.Redetermination of Some Early Focal MechanismSolutions of Chinese Earthquakes[J].Seismological andGeomangnetic Observation and Research,1994,15(5):1-9.
[14]阚荣举,张四昌,晏凤桐,等.我国西南地区现代构造应力场与现代构造活动特征的探讨[J].地球物理学报,1977,20(2):96-109.KAN Rong-ju,ZHANG Si-chang,YAN Feng-tong,et al.Present Tectonic Stress Field and Its Relation to theCharacteristics of Recent Tectonic Activity in South-western China[J].Chinese Journal of Geophysics,1977,20(2):96-109.
[15]阚荣举,王绍晋,黄崐,等.中国西南地区现代构造应力场与板内断块相对运动[J].地震地质,1983,5(2):79-90.KAN Rong-ju,WANG Shao-jin,HUANG Kun,et al.Modern Tectonic Stress Field and Relative Motion ofIntraplate Block in Southwestern China[J].Seismologyand Geology,1983,5(2):79-90.
[16]成尔林.四川及其邻区现代构造应力场和现代构造运动特征[J].地震学报,1981,3(3):231-241.CHENG Er-lin.Recent Tectonic Stress Field andTectonic Movement of the Sichuan Province and ItsVicinity[J].Acta Seismologica Sinica,1981,3(3):231-241.
[17]程万正,陈天长.1989年巴塘6.7级震群的复杂时-空扩展和震源力学机制[J].地震学报,1994,16(2):153-159.CHENG Wan-zheng,CHEN Tian-chang.ComplexTemporal and Spacial Extension and Focal MechanismSolutions of 1989Batang Ms6.7Earthquake[J].ActaSeismologica Sinica,1994,16(2):153-159.
[18]程万正,李桂芳,乔惠珍,等.四川沐川5.7级震群子序列的震源参数变化[J].中国地震,2002,18(2):203-213.CHENG Wan-zheng,LI Gui-fang,QIAO Hui-zhen,et al.Changes in Hypocenter Parameters of EarthquakeSwarm(Ms5.7)Sequence in Muchuan,Sichuan[J].Earthquake Research in China,2002,18(2):203-213.
[19]程万正,陈天长,魏娅玲,等.2001年四川雅江6级地震的前震与余震震源参数的变化[J].地震学报,2003,25(4):351-360.CHENG Wan-zheng,CHEN Tian-chang,WEI Ya-ling,et al.Changes in Source Parameters of Foreshocksand Aftershocks of the 2001Yajiang Ms6.0Earth-quake,Sichuan[J].Acta Seismologica Sinica,2003,25(4):351-360.
[20]AKI K.Earthquake Generating Stress in Japan for theYears 1961to 1963Obtained by Smoothing the FirstMotion Radiation Patterns[J].Bulletin of the Earth-quake Research Institute,1966,44(2):447-471.
[21]ELLSWORTH W L,XU Z H.Determination of theStress Tensor from Focal Mechanism Data[J].Eos,Transactions American Geophysical Union,1980,61(46):1117.
[22]MICHAEL A J.Use of Focal Mechanism to Deter-mine Stress:A Control Study[J].Journal of Geophys-ical Research:Solid Earth,1987,92(B1):357-368.
[23]许忠淮,阎明,赵仲和.由多个小地震推断的华北地区构造应力场的方向[J].地震学报,1983,5(3):268-279.XU Zhong-huai,YAN Ming,ZHAO Zhong-he.Evalu-ation of the Direction of Tectonic Stress in North Chinafrom Recorded Data of a Large Number of SmallEarthquakes[J].Acta Seismologica Sinica,1983,5(3):268-279.
[24]许向彤,许忠淮,张东宁.求震源机制P波初动解的格点尝试概率法[J].地震地磁观测与研究,1995,16(4):34-42.XU Xiang-tong,XU Zhong-huai,ZHANG Dong-ning.A Probabilistic Grid Test Method of DeterminingEarthquake Focal Mechanisms Using P-wave OnsetPolarity Data[J].Seismological and GeomagneticObservation and Research,1995,16(4):34-42.
[25]范俊喜,马瑾,刁桂苓.由小震震源机制解得到的鄂尔多斯周边构造应力场[J].地震地质,2003,25(1):88-99.FAN Jun-xi,MA Jin,DIAO Gui-ling.ContemporaryTectonic Stress Field Around the Ordos Fault BlockInferred from Earthquake Focal Mechanisms[J].Seis-mology and Geology,2003,25(1):88-99.
[26]刁桂苓,王海涛,高国英,等.伽师强震系列应力场的转向过程[J].地球物理学报,2005,48(5):1062-1068.DIAO Gui-ling,WANG Hai-tao,GAO Guo-ying,et al.ADeflection Process for Stress Field of the JiashiStrong Earthquake Sequence[J].Chinese Journal ofGeophysics,2005,48(5):1062-1068.
[27]张红艳,谢富仁,崔效锋,等.张渤带陆地段现代构造应力场的非均匀特征[J].中国地震,2009,25(3):314-324.ZHANG Hong-yan,XIE Fu-ren,CUI Xiao-feng,et al.Research on Heterogeneity of the Present TectonicStress Field at the Overland Part of the Zhangjiakou-Bohai Fault Zone[J].Earthquake Research in China,2009,25(3):314-324.
[28]谢富仁,崔效锋,赵建涛,等.中国大陆及邻区现代构造应力场分区[J].地球物理学报,2004,47(4):654-662.XIE Fu-ren,CUI Xiao-feng,ZHAO Jian-tao,et al.Re-gional Division of the Recent Tectonic Stress Field inChina and Adjacent Areas[J].Chinese Journal of Geophysics,2004,47(4):654-662.
[2]张勇,许力生,陈运泰.芦山4.20地震破裂过程及其致灾特征初步分析[J].地球物理学报,2013,56(4):1408-1411.ZHANG Yong,XU Li-sheng,CHEN Yun-tai,et al.Rupture Process of the Lushan 4.20Earthquake andPreliminary Analysis on the Disaster-causing Mecha-nism[J].Chinese Journal of Geophysics,2013,56(4):1408-1411.
[3]邓起东,陈社发,赵小麟.龙门山及其邻区的构造和地震活动及动力学[J].地震地质,1994,16(4):389-403.DENG Qi-dong,CHEN She-fa,ZHAO Xiao-lin.Tec-tonics,Seismisity and Dynamics of LongmenshanMountains and Its Adjacent Regions[J].Seismologyand Geology,1994,16(4):389-403.
[4]杨晓平,蒋溥,宋方敏,等.龙门山断裂带南段错断晚更新世以来地层的证据[J].地震地质,1999,21(4):341-345.YANG Xiao-ping,JIANG Pu,SONG Fang-min,et al.The Evidence of the South Longmenshan Fault ZonesCutting Late Quaternary Stratum[J].Seismology andGeology,1999,21(4):341-345.
[5]李勇,周荣军,DENSMORE A L,等.青藏高原东缘龙门山晚新生代走滑-逆冲作用的地貌标志[J].第四纪研究,2006,26(1):40-51.LI Yong,ZHOU Rong-jun,DENSMORE A L,et al.Geomorphic Evidence for the Late Cenozoic Strike-slipping and Thrusting in Longmen Mountain at theEastern Margin of the Tibetan Plateau[J].QuaternarySciences,2006,26(1):40-51.
[6]陈国光,计凤桔,周荣军,等.龙门山断裂带晚第四纪活动性分段的初步研究[J].地震地质,2007,29(3):657-673.CHEN Guo-guang,JI Feng-ju,ZHOU Rong-jun,et al.Primary Research of Activity Segmentation of Long-menshan Fault Zone Since Late Quaternary[J].Seismology and Geology,2007,29(3):657-673.
[7]贾秋鹏,贾东,朱艾斓,等.青藏高原东缘龙门山冲断带与四川盆地的现今构造表现:数字地形和地震活动证据[J].地质科学,2007,42(1):31-44.JIA Qiu-peng,JIA Dong,ZHU Ai-lan,et al.ActiveTectonics in the Longmenshan Thrust Belt to theEastern Qinghai-Tibetan Plateau and Sichuan Basin:Evidence from Topography and Seismicity[J].ChineseJournal of Geology,2007,42(1):31-44.
[8]徐锡伟,闻学泽,叶建青,等.汶川Ms8.0地震地表破裂带及其发震构造[J].地震地质,2008,30(3):597-629.XU Xi-wei,WEN Xue-ze,YE Jian-qing,et al.The Ms8.0Wenchuan Earthquake Surface Ruptures and ItsSeismogenic Structure[J].Seismology and Geology,2008,30(3):597-629.
[9]徐锡伟,陈桂华,于贵华,等.芦山地震发震构造及其与汶川地震关系讨论[J].地学前缘,2013,20(3):11-20.XU Xi-wei,CHEN Gui-hua,YU Gui-hua,et al.Seis-mogenic Structure of Lushan Earthquake and ItsRelationship with Wenchuan Earthquake[J].EarthScience Frontiers,2013,20(3):11-20.
[10]谢富仁,陈群策,崔效锋,等.中国大陆地壳应力环境研究[M].北京:地质出版社,2003.XIE Fu-ren,CHEN Qun-ce,CUI Xiao-feng,et a1.Researchon Continental Crustal Stress Environment in China[M].Beijing:Geological Publishing House,2003.
[11]鄢家全,时振梁,环文林,等.强余震的断层面解特征[J].地震学报,1980,2(4):395-403.YAN Jia-quan,SHI Zhen-Liang,HUAN Wen-Lin,et al.The Characteristics of Fault Plane Solutions of StrongAftershocks[J].Acta Seismologica Sinica,1980,2(4):395-403.
[12]ZHOU H L,LIU H L,KANAMORI H.Source Pro-cesses of Large Earthquakes Along the XianshuiheFault in Southwestern China[J].Bulletin of the Seis-mological Society of America,1983,73(2):537-551.
[13]许忠淮,汪素云,高阿甲,等.我国部分早期震源机制解答的重新测定[J].地震地磁观测与研究,1994,15(5):1-9.XU Zhong-huai,WANG Su-yun,GAO A-jia,et al.Redetermination of Some Early Focal MechanismSolutions of Chinese Earthquakes[J].Seismological andGeomangnetic Observation and Research,1994,15(5):1-9.
[14]阚荣举,张四昌,晏凤桐,等.我国西南地区现代构造应力场与现代构造活动特征的探讨[J].地球物理学报,1977,20(2):96-109.KAN Rong-ju,ZHANG Si-chang,YAN Feng-tong,et al.Present Tectonic Stress Field and Its Relation to theCharacteristics of Recent Tectonic Activity in South-western China[J].Chinese Journal of Geophysics,1977,20(2):96-109.
[15]阚荣举,王绍晋,黄崐,等.中国西南地区现代构造应力场与板内断块相对运动[J].地震地质,1983,5(2):79-90.KAN Rong-ju,WANG Shao-jin,HUANG Kun,et al.Modern Tectonic Stress Field and Relative Motion ofIntraplate Block in Southwestern China[J].Seismologyand Geology,1983,5(2):79-90.
[16]成尔林.四川及其邻区现代构造应力场和现代构造运动特征[J].地震学报,1981,3(3):231-241.CHENG Er-lin.Recent Tectonic Stress Field andTectonic Movement of the Sichuan Province and ItsVicinity[J].Acta Seismologica Sinica,1981,3(3):231-241.
[17]程万正,陈天长.1989年巴塘6.7级震群的复杂时-空扩展和震源力学机制[J].地震学报,1994,16(2):153-159.CHENG Wan-zheng,CHEN Tian-chang.ComplexTemporal and Spacial Extension and Focal MechanismSolutions of 1989Batang Ms6.7Earthquake[J].ActaSeismologica Sinica,1994,16(2):153-159.
[18]程万正,李桂芳,乔惠珍,等.四川沐川5.7级震群子序列的震源参数变化[J].中国地震,2002,18(2):203-213.CHENG Wan-zheng,LI Gui-fang,QIAO Hui-zhen,et al.Changes in Hypocenter Parameters of EarthquakeSwarm(Ms5.7)Sequence in Muchuan,Sichuan[J].Earthquake Research in China,2002,18(2):203-213.
[19]程万正,陈天长,魏娅玲,等.2001年四川雅江6级地震的前震与余震震源参数的变化[J].地震学报,2003,25(4):351-360.CHENG Wan-zheng,CHEN Tian-chang,WEI Ya-ling,et al.Changes in Source Parameters of Foreshocksand Aftershocks of the 2001Yajiang Ms6.0Earth-quake,Sichuan[J].Acta Seismologica Sinica,2003,25(4):351-360.
[20]AKI K.Earthquake Generating Stress in Japan for theYears 1961to 1963Obtained by Smoothing the FirstMotion Radiation Patterns[J].Bulletin of the Earth-quake Research Institute,1966,44(2):447-471.
[21]ELLSWORTH W L,XU Z H.Determination of theStress Tensor from Focal Mechanism Data[J].Eos,Transactions American Geophysical Union,1980,61(46):1117.
[22]MICHAEL A J.Use of Focal Mechanism to Deter-mine Stress:A Control Study[J].Journal of Geophys-ical Research:Solid Earth,1987,92(B1):357-368.
[23]许忠淮,阎明,赵仲和.由多个小地震推断的华北地区构造应力场的方向[J].地震学报,1983,5(3):268-279.XU Zhong-huai,YAN Ming,ZHAO Zhong-he.Evalu-ation of the Direction of Tectonic Stress in North Chinafrom Recorded Data of a Large Number of SmallEarthquakes[J].Acta Seismologica Sinica,1983,5(3):268-279.
[24]许向彤,许忠淮,张东宁.求震源机制P波初动解的格点尝试概率法[J].地震地磁观测与研究,1995,16(4):34-42.XU Xiang-tong,XU Zhong-huai,ZHANG Dong-ning.A Probabilistic Grid Test Method of DeterminingEarthquake Focal Mechanisms Using P-wave OnsetPolarity Data[J].Seismological and GeomagneticObservation and Research,1995,16(4):34-42.
[25]范俊喜,马瑾,刁桂苓.由小震震源机制解得到的鄂尔多斯周边构造应力场[J].地震地质,2003,25(1):88-99.FAN Jun-xi,MA Jin,DIAO Gui-ling.ContemporaryTectonic Stress Field Around the Ordos Fault BlockInferred from Earthquake Focal Mechanisms[J].Seis-mology and Geology,2003,25(1):88-99.
[26]刁桂苓,王海涛,高国英,等.伽师强震系列应力场的转向过程[J].地球物理学报,2005,48(5):1062-1068.DIAO Gui-ling,WANG Hai-tao,GAO Guo-ying,et al.ADeflection Process for Stress Field of the JiashiStrong Earthquake Sequence[J].Chinese Journal ofGeophysics,2005,48(5):1062-1068.
[27]张红艳,谢富仁,崔效锋,等.张渤带陆地段现代构造应力场的非均匀特征[J].中国地震,2009,25(3):314-324.ZHANG Hong-yan,XIE Fu-ren,CUI Xiao-feng,et al.Research on Heterogeneity of the Present TectonicStress Field at the Overland Part of the Zhangjiakou-Bohai Fault Zone[J].Earthquake Research in China,2009,25(3):314-324.
[28]谢富仁,崔效锋,赵建涛,等.中国大陆及邻区现代构造应力场分区[J].地球物理学报,2004,47(4):654-662.XIE Fu-ren,CUI Xiao-feng,ZHAO Jian-tao,et al.Re-gional Division of the Recent Tectonic Stress Field inChina and Adjacent Areas[J].Chinese Journal of Geophysics,2004,47(4):654-662.
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