2016年12月8日呼图壁M_S6.2地震序列重定位与发震构造
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摘要
基于新疆区域数字地震台网震相观测报告,采用HypoDD方法精确定位了呼图壁M_S6.2地震序列中ML≥1.0地震的震源位置,采用CAP方法反演了主震和余震序列中部分M_L≥4.0地震的震源机制,从而综合分析了呼图壁地震序列的空间分布特征、震源机制和可能的发震构造。结果显示,主震位置为43.775 9°N,86.363 4°E,初始破裂深度约15.388km,震源矩心深度约17km。地震序列沿NWW向单侧扩展,展布长度约15km,震源深度主要分布在5~15km范围。深度剖面显示发震断层面倾向N,运动性质以逆冲为主。主震最佳双力偶震源机制解节面Ⅰ:走向292°/倾角62°/滑动角80°,节面Ⅱ:走向132°/倾角30°/滑动角108°,表明该地震为1次逆冲型地震事件。节面I倾角与震源深度剖面倾角具有较好的一致性,结合余震分布推断节面I为本次地震的发震断层面。综合地震序列空间分布特征、震源机制以及震源区地质构造情况,初步推测呼图壁6.2级地震发震构造可能为齐古背斜以南深部隐伏逆冲断坡上的1条反冲断层。本次地震是天山向准噶尔盆地扩展的应力作用下发生的1次"褶皱型"地震。
Based on the digital waveforms of Xinjiang Seismic Network,the Hutubi MS6. 2 earthquake sequence( ML≥1. 0) was relocated precisely by HypoDD.The best double-couple focal mechanisms of the main shock and aftershocks of ML≥4. 0 were determined by the CAP method. We analyzed the characteristics of spatial distribution,focal mechanisms and the seismogenic structure of earthquake sequence. The results show that the main shock is located at 43. 775 9°N,86. 363 4°E; the depth of the initial rupture and centriod is about 15. 388 km and 17 km. The earthquake sequence extends unilaterally along NWW direction with an extension length of about 15 km and a depth ranging 5 ~15 km. The characteristics of the depth profiles show that the seismogenic fault plane dips northward and the faulting is dominated by thrusting. The nodal planes parameters of the best double-couple focal mechanisms are: strike 292°,dip 62° and rake 80° for nodal plane I,and strike 132°,dip 30°and rake 108° for nodal plane Ⅱ,indicating that the main shock is of thrust faulting. The dip of nodal planeⅠ is consistent with the dip of the depth profile,which is inferred to be the fault plane of seismogenic fault of this earthquake. According to the comprehensive analysis of the relocation results,the focal mechanism and geological structure in the source region,it is preliminarily inferred that the seismogenic structure of the Hutubi MS6. 2 earthquake may be a backthrust on the deeper concealed thrust slope at the south of Qigu anticline. The earthquake is a "folding "earthquake taking place under the stress field of Tianshan expanding towards the Junggar Basin.
Based on the digital waveforms of Xinjiang Seismic Network,the Hutubi MS6. 2 earthquake sequence( ML≥1. 0) was relocated precisely by HypoDD.The best double-couple focal mechanisms of the main shock and aftershocks of ML≥4. 0 were determined by the CAP method. We analyzed the characteristics of spatial distribution,focal mechanisms and the seismogenic structure of earthquake sequence. The results show that the main shock is located at 43. 775 9°N,86. 363 4°E; the depth of the initial rupture and centriod is about 15. 388 km and 17 km. The earthquake sequence extends unilaterally along NWW direction with an extension length of about 15 km and a depth ranging 5 ~15 km. The characteristics of the depth profiles show that the seismogenic fault plane dips northward and the faulting is dominated by thrusting. The nodal planes parameters of the best double-couple focal mechanisms are: strike 292°,dip 62° and rake 80° for nodal plane I,and strike 132°,dip 30°and rake 108° for nodal plane Ⅱ,indicating that the main shock is of thrust faulting. The dip of nodal planeⅠ is consistent with the dip of the depth profile,which is inferred to be the fault plane of seismogenic fault of this earthquake. According to the comprehensive analysis of the relocation results,the focal mechanism and geological structure in the source region,it is preliminarily inferred that the seismogenic structure of the Hutubi MS6. 2 earthquake may be a backthrust on the deeper concealed thrust slope at the south of Qigu anticline. The earthquake is a "folding "earthquake taking place under the stress field of Tianshan expanding towards the Junggar Basin.
引文
陈杰,卢演俦,丁国瑜.2001.塔里木西缘晚新生代造山过程的记录:磨拉石建造及生长地层和生长不整合[J].第四纪研究,21(6):528-539.CHEN Jie,LU Yan-chou,DING Guo-yu.2001.Records of late Cenozoic mountain building in western Tarim Basin:Molasses,growth strata and growth unconformity[J].Quaternary Sciences,21(6):528-539(in Chinese).
邓起东,冯先岳,张培震,等.2000.天山活动构造[M].北京:地震出版社.DENG Qi-dong,FENG Xian-yue,ZHANG Pei-zhen,et al.2000.Active Tectonics of Chinese Tianshan Mountains[M].Seismological Press,Beijing(in Chinese).
房立华,吴建平,王未来,等.2013.四川庐山MS7.0地震及其余震序列重定位[J].科学通报,58(20):1901-1909.FANG Li-hua,WU Jian-ping,WANG Wei-lai,et al.2013.Relocation of the mainshock and aftershock sequences of MS7.0 Sichuan Lushan earthquake[J].Chinese Science Bulletin,58(28-29):3451-3459.
房立华,吴建平,王未来,等.2014.2014年新疆于田MS7.3地震序列重定位[J].地球物理学报,58(3):802-808.FANG Li-hua,WU Jian-ping,WANG Wei-lai,et al.2014.Relocation of the 2014 MS7.3 earthquake sequence in Yutian,Xinjiang[J].Chinese Journal of Geophysics,58(3):802-808(in Chinese).
房立华,吴建平,张天中,等.2011.2011年云南盈江MS5.8地震及其余震序列重定位[J].地震学报,33(2):262-267.FANG Li-hua,WU Jian-ping,ZHANG Tian-zhong,et al.2011.Relocation of mainshock and aftershocks of the 2011Yingjiang MS5.8 earthquake in Yunnan[J].Acta Seismologica Sinica,33(2):262-267(in Chinese).
冯先岳.1997.新疆古地震[M].乌鲁木齐:新疆科技卫生出版社.FENG Xian-yue.1997.The Paleoearthquakes in Xinjiang Region[M].Xinjiang Sci-Tech and Public Health Press,Urumqi(in Chinese).
冯先岳,邓起东,石建邦,等.1991.天山南北缘活动构造及其演化[M]∥《活动断裂研究》编委会编.活动断裂构造(1).北京:地震出版社:1-16.FENG Xian-yue,DENG Qi-dong,SHI Jian-bang,et al.1991.Active tectonics of the southern and northern Tianshan Mountains and its tectonic evolution[M]∥Institute of Geology.Research on Active Faults(1).Seismological Press,Beijing:1-16(in Chinese).
高国英,聂晓红,龙海英.2010.2003-2008年新疆区域构造应力场特征探讨[J].地震地质,32(1):70-79.doi:10.3969/j.issn.0253-4967.2010.01.007.GAO Guo-ying,NIE Xiao-hong,LONG Hai-ying.2010.Discussion on the characteristics of regional tectonic stress field of Xinjiang from 2003 to 2008[J].Seismology and Geology,32(1):70-79(in Chinese).
管树巍,李本亮,何登发,等.2007.晚新生代以来天山南、北麓冲断作用的定量分析[J].地质学报,81(6):725-744.GAN Shu-wei,LI Bei-liang,HE Deng-fa,et al.2007.Late Cenozoic active fold-and-thrust belts in the southern and northern flanks of Tianshan[J].Acta Geologica Sinica,81(6):725-744(in Chinese).
黄媛,吴建平,张天中,等.2008.汶川8.0级大地震及其余震序列重定位研究[J].中国科学(D辑),38(10):1242-1249.HUANG Yuan,WU Jian-ping,ZHANG Tian-zhong,et al.2008.Relocation of the M8.0 Wenchuan earthquake and its aftershock sequence[J].Science in China(Ser D),51(12):1703-1711.
刘和甫,梁慧社,蔡立国,等.1994.天山两侧前陆冲断系构造样式与前陆盆地演化[J].地球科学(中国地质大学学报),19(6):727-741.LIU He-fu,LIANG Hui-she,CAI Li-guo,et al.1994.Evolution and structural style of Tianshan and adjacent basins,northwestern China[J].Earth Science-Journal of China University of Geosciences,19(6):727-741(in Chinese).
吕红华,李有利.2010.天山北麓活动背斜带的变形特征[J].第四纪研究,30(5):1003-1011.L Hong-hua,LI You-li.2010.Tectonic deformation of active fault-related fold belts in the north piedmont of the central Tianshan Mountains,NW China[J].Quaternary Sciences,30(5):1003-1011(in Chinese).
吕坚,苏金蓉,靳玉科,等.2008b.汶川8.0级地震序列重新定位及其发震构造初探[J].地震地质,30(4):917-925.doi:10.3969/j.issn.0253-4967.2008.04.008.L Jian,SU Jin-rong,JIN Yu-ke,et al.2008b.Discussion on relocation and seismo-tectonics of the MS8.0Wenchuan earthquake sequences[J].Seismology and Geology,30(4):917-925(in Chinese).
吕坚,郑勇,倪四道,等.2008a.2005年11月26日九江-瑞昌MS5.7、MS4.8地震的震源机制解与发震构造研究[J].地球物理学报,51(1):158-164.L Jian,ZHENG Yong,NI Si-dao,et al.2008a.Focal mechanisms and seismogenic structures of the MS5.7 and MS4.8 Jiujiang-Ruichang earthquakes of Nov.26,2005[J].Chinese Journal of Geophysics,51(1):158-164(in Chinese).
邵学钟,张家茹,范会吉,等.1996.天山造山带地壳结构与构造:乌鲁木齐-库尔勒地震转波测深剖面[J].地球物理学报,39(3):336-346.SHAO Xue-zhong,ZHANG Jia-ru,FAN Hui-ji,et al.1996.The crust structures of Tianshan orogenic belt:A deep sounding work by converted waves of earthquakes alongrümqi-Korla profile[J].Chinese Journal of Geophysics,39(3):336-346(in Chinese).
王椿镛,楼海,魏修成,等.2001.天山北缘的地壳结构和1906年玛纳斯地震的地震构造[J].地震学报,23(5):460-470.WANG Chun-yong,LOU Hai,WEI Xiu-cheng,et al.2001.Crustal structure in northern margin of Tianshan Mountains and seismotectonics of 1906 Manas earthquake[J].Acta Seismologica Sinica,23(5):460-470(in Chinese).
王未来,吴建平,房立华,等.2014.2014年云南鲁甸MS6.5地震序列的双差定位[J].地球物理学报,57(9):3042-3051.WANG Wei-lai,WU Jian-ping,FANG Li-hua,et al.2014.Double difference location of the Ludian MS6.5 earthquake sequences in Yunnan Province in 2014[J].Chinese Journal of Geophysics,57(9):3042-3051(in Chinese).
杨晓平,邓起东,张培震,等.1998.北天山地区活动逆断裂-褶皱带构造与潜在震源区估计[J].地震地质,20(3):193-200.YANG Xiao-ping,DENG Qi-dong,ZHANG Pei-zhen,et al.1998.Active reverse fault-fold zones and estimation of potential earthquake sources in northern Tianshan[J].Seismology and Geology,20(3):193-200(in Chinese).
杨晓平,邓起东,张培震,等.2008.天山山前主要推覆构造区的地壳缩短[J].地震地质,30(1):111-131.YANG Xiao-ping,DENG Qi-dong,ZHANG Pei-zhen,et al.2008.Crustal shortening of major nappe structures on the front margins of the Tianshan[J].Seismology and Geology,30(1):111-131(in Chinese).
杨晓平,李安,黄伟亮.2012.天山北麓活动褶皱带晚第四纪时期隆升的差异性[J].中国科学(D辑),42(12):1877-1888.YANG Xiao-ping,LI An,HUANG Wei-liang.2013.Uplift differential of active fold zones during the late Quaternary,northern piedmonts of the Tianshan Mountains,China[J].Science in China(Ser D),56(5):794-805.
张培震,邓起东,徐锡伟,等.1994.盲断裂、褶皱地震与新疆1906年玛纳斯地震[J].地震地质,16(3):193-204.ZHANG Pei-zhen,DENG Qi-dong,XU Xi-wei,et al.1994.Blind thrust,folding earthquake,and the 1906 Manas earthquakes,Xinjiang[J].Seismology and Geology,16(3):193-204(in Chinese).
郑勇,马宏生,吕坚,等.2009.汶川地震强余震(MS≥5.6)的震源机制解及其与发震构造的关系[J].中国科学(D辑),39(4):413-426.ZHENG Yong,MA Hong-sheng,L Jian,et al.2009.Source mechanism of strong aftershocks(MS5.6)of the2008/05/12 Wenchuan earthquake and the implication for seismotectonics[J].Science in China(Ser D),52(6):739-753.
Deng Q D,Feng X Y,Zhang P Z,et al.1996.Active reverse fault-fold zones and earthquakes along northern Tianshan,Xinjiang,China[J].Seismology and Geology,18(Suppl):21-36(in Chinese).
Ekstr9m G,England P.1989.Seismic strain rates in regions of distributed continental deformation[J].Journal of Geophysical Research:Solid Earth,94(B8):10231-10257.
Guan S W,Stockmeyer J M,Shar J H,et al.2016.Structural inversion,imbricate wedging,and out-of-sequence thrusting in the southern Junggar fold-and-thrust belt,northern Tian Shan,China[J].AAPG Bulletin,100(9):1443-1468.
Stein R S,King G C P.1984.Seismic potential revealed by surface folding:1983 Coalinga,California,earthquake[J].Science,224(4651):869-872.
Stein R S,Yeats R S.1989.Hidden earthquakes[J].Scientific American,260:48-57.
Waldhauser F,Ellsworth W L.2000.A double-difference earthquake location algorithm:Method and application to the Northern Hayward Fault,California[J].Bulletin of the Seismological Society of America,90(6):1353-1368.
Yeats R S.2000.The 1968 Inangahua,New Zealand,and 1994 Northridge,California,earthquakes:Implications for northwest Nelson[J].New Zealand Journal of Geology and Geophysics,43(4):587-599.
Zhao L S,Helmberger D V.1994.Source estimation from broadband regional seismograms[J].Bulletin of the Seismological Society of America,84(1):91-104.
Zhu L P,Helmberger D V.1996.Advancement in source estimation techniques using broadband regional seismograms[J].Bulletin of the Seismological Society of America,86(5):1634-1641.
邓起东,冯先岳,张培震,等.2000.天山活动构造[M].北京:地震出版社.DENG Qi-dong,FENG Xian-yue,ZHANG Pei-zhen,et al.2000.Active Tectonics of Chinese Tianshan Mountains[M].Seismological Press,Beijing(in Chinese).
房立华,吴建平,王未来,等.2013.四川庐山MS7.0地震及其余震序列重定位[J].科学通报,58(20):1901-1909.FANG Li-hua,WU Jian-ping,WANG Wei-lai,et al.2013.Relocation of the mainshock and aftershock sequences of MS7.0 Sichuan Lushan earthquake[J].Chinese Science Bulletin,58(28-29):3451-3459.
房立华,吴建平,王未来,等.2014.2014年新疆于田MS7.3地震序列重定位[J].地球物理学报,58(3):802-808.FANG Li-hua,WU Jian-ping,WANG Wei-lai,et al.2014.Relocation of the 2014 MS7.3 earthquake sequence in Yutian,Xinjiang[J].Chinese Journal of Geophysics,58(3):802-808(in Chinese).
房立华,吴建平,张天中,等.2011.2011年云南盈江MS5.8地震及其余震序列重定位[J].地震学报,33(2):262-267.FANG Li-hua,WU Jian-ping,ZHANG Tian-zhong,et al.2011.Relocation of mainshock and aftershocks of the 2011Yingjiang MS5.8 earthquake in Yunnan[J].Acta Seismologica Sinica,33(2):262-267(in Chinese).
冯先岳.1997.新疆古地震[M].乌鲁木齐:新疆科技卫生出版社.FENG Xian-yue.1997.The Paleoearthquakes in Xinjiang Region[M].Xinjiang Sci-Tech and Public Health Press,Urumqi(in Chinese).
冯先岳,邓起东,石建邦,等.1991.天山南北缘活动构造及其演化[M]∥《活动断裂研究》编委会编.活动断裂构造(1).北京:地震出版社:1-16.FENG Xian-yue,DENG Qi-dong,SHI Jian-bang,et al.1991.Active tectonics of the southern and northern Tianshan Mountains and its tectonic evolution[M]∥Institute of Geology.Research on Active Faults(1).Seismological Press,Beijing:1-16(in Chinese).
高国英,聂晓红,龙海英.2010.2003-2008年新疆区域构造应力场特征探讨[J].地震地质,32(1):70-79.doi:10.3969/j.issn.0253-4967.2010.01.007.GAO Guo-ying,NIE Xiao-hong,LONG Hai-ying.2010.Discussion on the characteristics of regional tectonic stress field of Xinjiang from 2003 to 2008[J].Seismology and Geology,32(1):70-79(in Chinese).
管树巍,李本亮,何登发,等.2007.晚新生代以来天山南、北麓冲断作用的定量分析[J].地质学报,81(6):725-744.GAN Shu-wei,LI Bei-liang,HE Deng-fa,et al.2007.Late Cenozoic active fold-and-thrust belts in the southern and northern flanks of Tianshan[J].Acta Geologica Sinica,81(6):725-744(in Chinese).
黄媛,吴建平,张天中,等.2008.汶川8.0级大地震及其余震序列重定位研究[J].中国科学(D辑),38(10):1242-1249.HUANG Yuan,WU Jian-ping,ZHANG Tian-zhong,et al.2008.Relocation of the M8.0 Wenchuan earthquake and its aftershock sequence[J].Science in China(Ser D),51(12):1703-1711.
刘和甫,梁慧社,蔡立国,等.1994.天山两侧前陆冲断系构造样式与前陆盆地演化[J].地球科学(中国地质大学学报),19(6):727-741.LIU He-fu,LIANG Hui-she,CAI Li-guo,et al.1994.Evolution and structural style of Tianshan and adjacent basins,northwestern China[J].Earth Science-Journal of China University of Geosciences,19(6):727-741(in Chinese).
吕红华,李有利.2010.天山北麓活动背斜带的变形特征[J].第四纪研究,30(5):1003-1011.L Hong-hua,LI You-li.2010.Tectonic deformation of active fault-related fold belts in the north piedmont of the central Tianshan Mountains,NW China[J].Quaternary Sciences,30(5):1003-1011(in Chinese).
吕坚,苏金蓉,靳玉科,等.2008b.汶川8.0级地震序列重新定位及其发震构造初探[J].地震地质,30(4):917-925.doi:10.3969/j.issn.0253-4967.2008.04.008.L Jian,SU Jin-rong,JIN Yu-ke,et al.2008b.Discussion on relocation and seismo-tectonics of the MS8.0Wenchuan earthquake sequences[J].Seismology and Geology,30(4):917-925(in Chinese).
吕坚,郑勇,倪四道,等.2008a.2005年11月26日九江-瑞昌MS5.7、MS4.8地震的震源机制解与发震构造研究[J].地球物理学报,51(1):158-164.L Jian,ZHENG Yong,NI Si-dao,et al.2008a.Focal mechanisms and seismogenic structures of the MS5.7 and MS4.8 Jiujiang-Ruichang earthquakes of Nov.26,2005[J].Chinese Journal of Geophysics,51(1):158-164(in Chinese).
邵学钟,张家茹,范会吉,等.1996.天山造山带地壳结构与构造:乌鲁木齐-库尔勒地震转波测深剖面[J].地球物理学报,39(3):336-346.SHAO Xue-zhong,ZHANG Jia-ru,FAN Hui-ji,et al.1996.The crust structures of Tianshan orogenic belt:A deep sounding work by converted waves of earthquakes alongrümqi-Korla profile[J].Chinese Journal of Geophysics,39(3):336-346(in Chinese).
王椿镛,楼海,魏修成,等.2001.天山北缘的地壳结构和1906年玛纳斯地震的地震构造[J].地震学报,23(5):460-470.WANG Chun-yong,LOU Hai,WEI Xiu-cheng,et al.2001.Crustal structure in northern margin of Tianshan Mountains and seismotectonics of 1906 Manas earthquake[J].Acta Seismologica Sinica,23(5):460-470(in Chinese).
王未来,吴建平,房立华,等.2014.2014年云南鲁甸MS6.5地震序列的双差定位[J].地球物理学报,57(9):3042-3051.WANG Wei-lai,WU Jian-ping,FANG Li-hua,et al.2014.Double difference location of the Ludian MS6.5 earthquake sequences in Yunnan Province in 2014[J].Chinese Journal of Geophysics,57(9):3042-3051(in Chinese).
杨晓平,邓起东,张培震,等.1998.北天山地区活动逆断裂-褶皱带构造与潜在震源区估计[J].地震地质,20(3):193-200.YANG Xiao-ping,DENG Qi-dong,ZHANG Pei-zhen,et al.1998.Active reverse fault-fold zones and estimation of potential earthquake sources in northern Tianshan[J].Seismology and Geology,20(3):193-200(in Chinese).
杨晓平,邓起东,张培震,等.2008.天山山前主要推覆构造区的地壳缩短[J].地震地质,30(1):111-131.YANG Xiao-ping,DENG Qi-dong,ZHANG Pei-zhen,et al.2008.Crustal shortening of major nappe structures on the front margins of the Tianshan[J].Seismology and Geology,30(1):111-131(in Chinese).
杨晓平,李安,黄伟亮.2012.天山北麓活动褶皱带晚第四纪时期隆升的差异性[J].中国科学(D辑),42(12):1877-1888.YANG Xiao-ping,LI An,HUANG Wei-liang.2013.Uplift differential of active fold zones during the late Quaternary,northern piedmonts of the Tianshan Mountains,China[J].Science in China(Ser D),56(5):794-805.
张培震,邓起东,徐锡伟,等.1994.盲断裂、褶皱地震与新疆1906年玛纳斯地震[J].地震地质,16(3):193-204.ZHANG Pei-zhen,DENG Qi-dong,XU Xi-wei,et al.1994.Blind thrust,folding earthquake,and the 1906 Manas earthquakes,Xinjiang[J].Seismology and Geology,16(3):193-204(in Chinese).
郑勇,马宏生,吕坚,等.2009.汶川地震强余震(MS≥5.6)的震源机制解及其与发震构造的关系[J].中国科学(D辑),39(4):413-426.ZHENG Yong,MA Hong-sheng,L Jian,et al.2009.Source mechanism of strong aftershocks(MS5.6)of the2008/05/12 Wenchuan earthquake and the implication for seismotectonics[J].Science in China(Ser D),52(6):739-753.
Deng Q D,Feng X Y,Zhang P Z,et al.1996.Active reverse fault-fold zones and earthquakes along northern Tianshan,Xinjiang,China[J].Seismology and Geology,18(Suppl):21-36(in Chinese).
Ekstr9m G,England P.1989.Seismic strain rates in regions of distributed continental deformation[J].Journal of Geophysical Research:Solid Earth,94(B8):10231-10257.
Guan S W,Stockmeyer J M,Shar J H,et al.2016.Structural inversion,imbricate wedging,and out-of-sequence thrusting in the southern Junggar fold-and-thrust belt,northern Tian Shan,China[J].AAPG Bulletin,100(9):1443-1468.
Stein R S,King G C P.1984.Seismic potential revealed by surface folding:1983 Coalinga,California,earthquake[J].Science,224(4651):869-872.
Stein R S,Yeats R S.1989.Hidden earthquakes[J].Scientific American,260:48-57.
Waldhauser F,Ellsworth W L.2000.A double-difference earthquake location algorithm:Method and application to the Northern Hayward Fault,California[J].Bulletin of the Seismological Society of America,90(6):1353-1368.
Yeats R S.2000.The 1968 Inangahua,New Zealand,and 1994 Northridge,California,earthquakes:Implications for northwest Nelson[J].New Zealand Journal of Geology and Geophysics,43(4):587-599.
Zhao L S,Helmberger D V.1994.Source estimation from broadband regional seismograms[J].Bulletin of the Seismological Society of America,84(1):91-104.
Zhu L P,Helmberger D V.1996.Advancement in source estimation techniques using broadband regional seismograms[J].Bulletin of the Seismological Society of America,86(5):1634-1641.