西藏米林6.9级地震发震断层判定及其构造属性讨论
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摘要
西藏米林6.9级地震是1950年察隅MS8.6级地震以来东构造结地区发生的第一个6级以上地震,由于地震发生在雅鲁藏布江大拐弯附近的无人区,野外应急科学考察没有发现明显的地震地表破裂带。根据林芝流动地震观测台网记录到的余震条带状分布、震后科学考察获得的地震烈度长轴方位、原有台阵观测震中分布以及GPS资料和野外地质调查分析,发现发震断层为NW向排龙—帮辛断裂,逆冲性质,为新生NW向边坝—达木断裂带中段组成部分;米林地震的发生预示东构造结地区地震活动强度加强,未来该地区发生7级以上地震危险性不容忽视。
Milinearthquake(MS6.9) has been the first above MS6 earthquake occurring in Eastern Himalayan Syntaxis areas since the Chayu MS8.6 in 1950. Due to Milin(MS6.9) occurred in a no man's land near the Great Bend of the Brahmaputra, no surface rupture zone was observed during the emergency scientific investigation in the epicenter. According to the belt distribution of aftershocks recorded by Linzhi earthquake mobile observatories network, the dominated axial azimuth of the earthquake intensities after earthquake, and the analysis of GPS data as well as field geological investigation, the seismogenic fault of the Milin earthquake is a NW–trending thrust fault, called the Palong–Bangxin fault, which may belong to the middle part of the new NW–trending Bianba-Damu fault zone. The occurrence of the Milin earthquake indicates that the intensity of seismic activity in Eastern Himalayan Syntaxis area is strengthened, and hence the seismic risk over 7 magnitude in this region cann't be ignored in the future.
Milinearthquake(MS6.9) has been the first above MS6 earthquake occurring in Eastern Himalayan Syntaxis areas since the Chayu MS8.6 in 1950. Due to Milin(MS6.9) occurred in a no man's land near the Great Bend of the Brahmaputra, no surface rupture zone was observed during the emergency scientific investigation in the epicenter. According to the belt distribution of aftershocks recorded by Linzhi earthquake mobile observatories network, the dominated axial azimuth of the earthquake intensities after earthquake, and the analysis of GPS data as well as field geological investigation, the seismogenic fault of the Milin earthquake is a NW–trending thrust fault, called the Palong–Bangxin fault, which may belong to the middle part of the new NW–trending Bianba-Damu fault zone. The occurrence of the Milin earthquake indicates that the intensity of seismic activity in Eastern Himalayan Syntaxis area is strengthened, and hence the seismic risk over 7 magnitude in this region cann't be ignored in the future.
引文
丁林,钟大赉.2013.印度与欧亚板块碰撞以来东喜马拉雅构造结的演化[J].地质科学,48(2):317-333.
李保昆,刁桂苓,徐锡伟,万永革,冯向东,邹立晔,苗春兰.2015.1950年西藏察隅M8.6强震序列震源参数复核[J].地球物理学报,58(11):4254-4265
刘焰,SIEBEL W,王猛.2006.东喜马拉雅构造结陆内变形过程的研究[J].地质学报,80(9):1274-1284.
任金卫,沈军,曹忠权,汪一鹏.2000.西藏东南部嘉黎断裂新知[J].地震地质,22(4):344-350.
沈军,汪一鹏,任金卫,曹忠权.2003.青藏高原东南部第四纪右旋剪切运动[J].新疆地质,21(1):120-125.
宋键,唐方头,邓志辉,肖根如,陈为涛.2013.青藏高原嘉黎断裂晚第四纪运动特征[J].北京大学学报(自然科学版),49(6):973-980.
徐锡伟,吴熙彦,于贵华,谭锡斌,李康.2017.中国大陆高震级地震危险区判定的地震地质学标志及其应用[J].地震地质,39(2):219-275.
许志琴,蔡志慧,张泽明,李化启,陈方远,唐泽民.2008.喜马拉雅东构造结-南迦巴瓦构造及组构运动学[J].岩石学报,24(7):1463-1476.
张进江,季建清,钟大赉,丁林,何顺东.2003.东喜马拉雅南迦巴瓦构造结的构造格局及形成过程探讨[J].中国科学(D辑),33(4):373-383.
张肇诚.1988.中国地震震例(1966-1975)[M].北京:地震出版社:222.
赵静,刘杰,任金卫,江在森,闫伟,岳冲.2019.汶川、芦山地震前龙门山断裂带地壳形变特征对比分析[J].地球学报,40(1):186-198.
ARMIJO R P,TAPPONNIER P,HAN Tonglin.1989.Late Cenozoic right-lateral strike-slip faulting in southern Tibet[J].Jour Geophys Res,94:2787-2838.
AVOUAC J P,TAPPONNIER P.1993.Kinematic model of active deformation in central Asia[J].Geophys.Res.Lett.,20:895-898.
BASAB M,SUJIT D.2015.Earthquake swarms near eastern Himalayan Syntaxis along Jiali Faultin Tibet:A seismotectonic appraisal[J].Geoscience Frontiers,6:715-722.
BEN-MENAHEM A,ABOODI E,SCHILD R.1974.The source of the great Assam earthquake-an interplate wedge motion[J].Physics of the Earth and Planetary Interiors,9(4):265-289.
BONDAR I,STORCHAK D.2011.Improved location procedures at the International Seismological Centre[J].Geophys.J.Int.,186(3):1220-1244.
CHEN W P,MOLNAR P.1977.Seismic moments of major earthquakes and the average rate of slip in central Asia[J].Journal of Geophysical Research,82(20):2945-2969.
DING Lin,ZHONG Da-lai.2013.The tectonic evolution of the eastern Himalaya syntaxis since the collision of the Indian and Eurasian plates[J].Chinese Journal of Geology,48(2):317-333(in Chinese with English abstract).
LI Bao-kun,DIAO Gui-lin,XU Xi-wei,WAN Yong-ge,FENGXiao-dong,ZOU Li-ye,MIAO Chun-lan.2015.Redetermination of the source parameters of the Zayu,Tibet M8.6 sequence in 1950[J].Chinese J.Geophys.,58(11):4254-4265(in Chinese with English abstract).
LIU Y,WOLFGANG S,WANG M.2006.Intracontinental deformed processes of the Eastern Himalayan Syntaxis[J].Actageologicasinica,80(9):1274-1284(in Chinese with English abstract).
REN Jin-wei,SHEN Jun,CAO Zhong-quan,WANG Yi-peng.2000.Quaternary faulting of Jiali fault,southeast Tibetan plateau[J].Seismology and geology,22(4):344-350(in Chinese with English abstract).
SHEN Jun,WANG Yi-peng,REN Jin-wei,CAO Zhong-quan.2003.Quaternary dextral shearing and crustal movement in southeast Tibetan Plateau[J].Xinjiang Geology,21(1):120-125(in Chinese).
SONG Jian,TANG Fang-tou,DENG Zhi-hui,XIAO Geng-ru,CHEN Wei-tao.2013.Late Quaternary movement characteristic of Jiali fault in Tibetan Plateau[J].Acta Scientiarum Naturalium Universitaties Pekinensis,49(6):973-980(in Chinese with English abstract).
TANAY D G,FEDERICA R,SUJIT D,BASAB M,SUJIT R,SOMNATH S.2015.Kinematics and strain rates of the Eastern Himalayan Syntaxis from new GPS campaigns in Northeast india[J].Tectonophysics,655:15-26.
XU Xi-wei,WU Xi-yan,YU Gui-hua,TAN Xi-bin,LI Kang.2017.Seismo-geological Signatures for Identifying M≥7.0Earthquake Risk Areas and Their Premilimary Application in Mainland China[J].Seismology and Geology,39(2):219-275(in Chinese with English abstract).
XU Zhi-qin,CAI Zhi-hui,ZHANG Ze-ming,LI Hua-qi,CHENFang-yuan,TANG Ze-min.2008.Tectonics and fabric kinematics of the Namche Barwa terrane,Eastern Himalayan Syntaxis[J].Acta Petrological Sinica,24(7):1463-1476(in Chinese with English abstract).
ZHANG Jin-jiang,JI Jian-qing,ZHONG Da-lai,DING Lin,HEShun-dong.2004.Structural pattern of eastern Himalayan syntaxis in Namjagbarwa and its formation process[J].Science in China Series D-Earth Sciences,47(2):138-150(in Chinese with English abstract).
ZHANG Zhao-chen.1988.Earthquake in China(1966-1975)[M].Beijing:Seismological Press:222(in Chinese).
ZHAO Jing,LIU Jie,REN Jin-wei,JIANG Zai-sen,YAN Wei,YUE Chong.2019.A Contrastive Analysis of Crustal Deformation Characteristics along the Longmen Shan Fault Zone before the MS8.0 Wenchuan Earthquake and the MS7.0 Lushan Earthquake[J].Acta Geoscientica Sinica,40(1):186-198(in Chinese with English abstract).
李保昆,刁桂苓,徐锡伟,万永革,冯向东,邹立晔,苗春兰.2015.1950年西藏察隅M8.6强震序列震源参数复核[J].地球物理学报,58(11):4254-4265
刘焰,SIEBEL W,王猛.2006.东喜马拉雅构造结陆内变形过程的研究[J].地质学报,80(9):1274-1284.
任金卫,沈军,曹忠权,汪一鹏.2000.西藏东南部嘉黎断裂新知[J].地震地质,22(4):344-350.
沈军,汪一鹏,任金卫,曹忠权.2003.青藏高原东南部第四纪右旋剪切运动[J].新疆地质,21(1):120-125.
宋键,唐方头,邓志辉,肖根如,陈为涛.2013.青藏高原嘉黎断裂晚第四纪运动特征[J].北京大学学报(自然科学版),49(6):973-980.
徐锡伟,吴熙彦,于贵华,谭锡斌,李康.2017.中国大陆高震级地震危险区判定的地震地质学标志及其应用[J].地震地质,39(2):219-275.
许志琴,蔡志慧,张泽明,李化启,陈方远,唐泽民.2008.喜马拉雅东构造结-南迦巴瓦构造及组构运动学[J].岩石学报,24(7):1463-1476.
张进江,季建清,钟大赉,丁林,何顺东.2003.东喜马拉雅南迦巴瓦构造结的构造格局及形成过程探讨[J].中国科学(D辑),33(4):373-383.
张肇诚.1988.中国地震震例(1966-1975)[M].北京:地震出版社:222.
赵静,刘杰,任金卫,江在森,闫伟,岳冲.2019.汶川、芦山地震前龙门山断裂带地壳形变特征对比分析[J].地球学报,40(1):186-198.
ARMIJO R P,TAPPONNIER P,HAN Tonglin.1989.Late Cenozoic right-lateral strike-slip faulting in southern Tibet[J].Jour Geophys Res,94:2787-2838.
AVOUAC J P,TAPPONNIER P.1993.Kinematic model of active deformation in central Asia[J].Geophys.Res.Lett.,20:895-898.
BASAB M,SUJIT D.2015.Earthquake swarms near eastern Himalayan Syntaxis along Jiali Faultin Tibet:A seismotectonic appraisal[J].Geoscience Frontiers,6:715-722.
BEN-MENAHEM A,ABOODI E,SCHILD R.1974.The source of the great Assam earthquake-an interplate wedge motion[J].Physics of the Earth and Planetary Interiors,9(4):265-289.
BONDAR I,STORCHAK D.2011.Improved location procedures at the International Seismological Centre[J].Geophys.J.Int.,186(3):1220-1244.
CHEN W P,MOLNAR P.1977.Seismic moments of major earthquakes and the average rate of slip in central Asia[J].Journal of Geophysical Research,82(20):2945-2969.
DING Lin,ZHONG Da-lai.2013.The tectonic evolution of the eastern Himalaya syntaxis since the collision of the Indian and Eurasian plates[J].Chinese Journal of Geology,48(2):317-333(in Chinese with English abstract).
LI Bao-kun,DIAO Gui-lin,XU Xi-wei,WAN Yong-ge,FENGXiao-dong,ZOU Li-ye,MIAO Chun-lan.2015.Redetermination of the source parameters of the Zayu,Tibet M8.6 sequence in 1950[J].Chinese J.Geophys.,58(11):4254-4265(in Chinese with English abstract).
LIU Y,WOLFGANG S,WANG M.2006.Intracontinental deformed processes of the Eastern Himalayan Syntaxis[J].Actageologicasinica,80(9):1274-1284(in Chinese with English abstract).
REN Jin-wei,SHEN Jun,CAO Zhong-quan,WANG Yi-peng.2000.Quaternary faulting of Jiali fault,southeast Tibetan plateau[J].Seismology and geology,22(4):344-350(in Chinese with English abstract).
SHEN Jun,WANG Yi-peng,REN Jin-wei,CAO Zhong-quan.2003.Quaternary dextral shearing and crustal movement in southeast Tibetan Plateau[J].Xinjiang Geology,21(1):120-125(in Chinese).
SONG Jian,TANG Fang-tou,DENG Zhi-hui,XIAO Geng-ru,CHEN Wei-tao.2013.Late Quaternary movement characteristic of Jiali fault in Tibetan Plateau[J].Acta Scientiarum Naturalium Universitaties Pekinensis,49(6):973-980(in Chinese with English abstract).
TANAY D G,FEDERICA R,SUJIT D,BASAB M,SUJIT R,SOMNATH S.2015.Kinematics and strain rates of the Eastern Himalayan Syntaxis from new GPS campaigns in Northeast india[J].Tectonophysics,655:15-26.
XU Xi-wei,WU Xi-yan,YU Gui-hua,TAN Xi-bin,LI Kang.2017.Seismo-geological Signatures for Identifying M≥7.0Earthquake Risk Areas and Their Premilimary Application in Mainland China[J].Seismology and Geology,39(2):219-275(in Chinese with English abstract).
XU Zhi-qin,CAI Zhi-hui,ZHANG Ze-ming,LI Hua-qi,CHENFang-yuan,TANG Ze-min.2008.Tectonics and fabric kinematics of the Namche Barwa terrane,Eastern Himalayan Syntaxis[J].Acta Petrological Sinica,24(7):1463-1476(in Chinese with English abstract).
ZHANG Jin-jiang,JI Jian-qing,ZHONG Da-lai,DING Lin,HEShun-dong.2004.Structural pattern of eastern Himalayan syntaxis in Namjagbarwa and its formation process[J].Science in China Series D-Earth Sciences,47(2):138-150(in Chinese with English abstract).
ZHANG Zhao-chen.1988.Earthquake in China(1966-1975)[M].Beijing:Seismological Press:222(in Chinese).
ZHAO Jing,LIU Jie,REN Jin-wei,JIANG Zai-sen,YAN Wei,YUE Chong.2019.A Contrastive Analysis of Crustal Deformation Characteristics along the Longmen Shan Fault Zone before the MS8.0 Wenchuan Earthquake and the MS7.0 Lushan Earthquake[J].Acta Geoscientica Sinica,40(1):186-198(in Chinese with English abstract).