昆仑山口西M_S 8.1地震同震影响场的数值模拟
|
摘要
根据野外调查得到的地震破裂以及同震位错分布,利用三维有限元模型研究了昆仑山口西MS8.1地震的同震位移场和同震应力场的分布,讨论了震后地震活动与同震应力场变化的关系。模拟的MS8.1地震同震位移场显示,东昆仑断裂带南北两侧的同震位移衰减程度存在差异,断裂带南部的同震位移衰减大于北部同震位移的衰减;同震应力场研究结果则表明,MS8.1地震的同震最大剪切应力主要集中在东昆仑断裂带的周边地区,最大剪切应力等值线沿断裂带密集分布,形成了高梯度带。MS8.1地震的发生使青藏活动地块区的地壳应力发生了剧烈的变化,可能导致研究区的地壳应力场得到松弛。库伦破裂应力的研究表明,昆仑山地震对其后发生的5次强余震有一定的触发作用,昆仑山口西MS8.1地震可能也触发了2003年的德令哈6.6级地震。
The 14 November 2001 MS 8.1 Kunlun earthquake at northern Tibet is the largest earthquake that occurred in the Chinese continent since 1950.We apply a three-dimensional(3-D)finite element numerical procedure to model the coseismic displacement and stress fields caused by the earthquake dislocations,which are constrained by field investigations.We then further investigate the stress interaction between the MS 8.1 earthquake and the intensive aftershocks.Our primary calculation shows that the coseismic displacement field is centralized around the east Kunlun Fault zone.And the attenuation of coseismic displacements on the south side of Kunlun Fault zone is larger than that on the north side.The calculated coseismic stress field also indicates that the calculated maximal shear stress field is centralized around the east Kunlun Fault zone,and the directions of the coseismic maximal principal stress are contrary to that of the background crustal stress filed of Tibet Plateau.It indicates that the earthquake relaxes the crustal stress state in Tibet Plateau.Finally,we study the stress interaction between the MS 8.1 earthquake and its intensive aftershocks.The calculated Coulomb stress changes of the MS8.1 great earthquake are in favor of triggering 3 aftershocks.
The 14 November 2001 MS 8.1 Kunlun earthquake at northern Tibet is the largest earthquake that occurred in the Chinese continent since 1950.We apply a three-dimensional(3-D)finite element numerical procedure to model the coseismic displacement and stress fields caused by the earthquake dislocations,which are constrained by field investigations.We then further investigate the stress interaction between the MS 8.1 earthquake and the intensive aftershocks.Our primary calculation shows that the coseismic displacement field is centralized around the east Kunlun Fault zone.And the attenuation of coseismic displacements on the south side of Kunlun Fault zone is larger than that on the north side.The calculated coseismic stress field also indicates that the calculated maximal shear stress field is centralized around the east Kunlun Fault zone,and the directions of the coseismic maximal principal stress are contrary to that of the background crustal stress filed of Tibet Plateau.It indicates that the earthquake relaxes the crustal stress state in Tibet Plateau.Finally,we study the stress interaction between the MS 8.1 earthquake and its intensive aftershocks.The calculated Coulomb stress changes of the MS8.1 great earthquake are in favor of triggering 3 aftershocks.
引文
陈杰,陈宇坤,丁国瑜,等.2003.2001年昆仑山口西8.1级地震地表破裂带[J].第四纪研究,23(6):629—639.CHEN Jie,CHENYu-kun,DING Guo-yu,et al.2003.Surface rupture zones of the2001earthquake withMS8.1westof Kunlun pass,northern Qinghai-Xizang Plateau[J].Quaternary Sciences,23(6):629—639(in Chinese).
郭良迁,张祖胜,李延兴,等.2004.昆仑山口西MS8.1级地震的形变应变场研究[J].地球物理学报,47(6):1068—1075.GUO Liang-qian,ZHANG Zu-sheng,LI Yan-xing,et al.2004.A study on the strain field associated with theMS=8.1Kunlunshan earthquake[J].Chinese J Geophys,47(6):1068—1075(in Chinese).
郝平,傅征祥,田勤俭,等.2004.昆仑山口西8.1级地震强余震库仑破裂应力触发研究[J].地震学报,26(1):30—37.HAO Ping,FUZheng-xiang,TIANQin-jian,et al.2004.Large aftershocks triggered by Coulomb failure stress follow-ing the2001MS8.1great Kunlun earthquake[J].Acta Seismologica Sinica,26(1):30—37(in Chinese).
李延兴,杨国华,李智,等.2003.中国大陆活动地块的运动与应变状态[J].中国科学(D辑),33(增刊):65—81.LI Yan-xing,YANG Guo-hua,LI Zhi,et al.2003.Movement and strain of active blocks in Chinese mainland[J].Sci-ence in China(Ser D),33(Suppl):65—81(in Chinese).
乔学军,王琪,杜瑞林,等.2002昆仑山口西MS8.1地震的地壳变形特征[J].大地测量与地球动力学,22(4):6—11.QIAO Xue-jun,WANG Qi,DU Rui-lin,et al.2002.Characteristics of crustal deformation relating toMS8.1Kunlun-shan earthquake[J].Journal of Geodesy and Geodynamics,22(4):6-11(in Chinese).
任金卫,王敏.2005.GPS观测的2001年昆仑山口西MS8.1级地震地壳变形[J].第四纪研究,25(1):34—44.REN Jin-wei,WANG Min.2005.GPS measured crustal deformation of theMS8.1Kunlun earthquake on November14th2001in Qinghai-Xizang plateau[J].Quaternary Sciences,25(1):34—44(in Chinese).
单新建,柳稼航,马超.2004.2001年昆仑山口西8.1级地震同震形变场特征的初步分析[J].地震学报,26(5):474—480.SHAN Xin-jian,LIU Jia-hang,MA Chao.2004.Preliminary analysis on characteristics of coseismic deformation asso-ciated withMS8.1western Kunlunshan pass earthquake in2001[J].Acta Seismologica Sinica,26(5):474—480(in Chinese).
沈正康,万永革,甘卫军,等.2003.东昆仑活动断裂带大地震之间的黏弹性应力触发研究[J].地球物理学报,46(6):786—795.SHEN Zheng-kang,WAN Yong-ge,GAN Wei-jun,et al.2003.Viscoelastic triggering among large earthquakes alongthe east Kunlun fault system[J].Chinese J Geophys,46(6):786—795(in Chinese).
王辉,张国民,石耀霖,等.2006.青藏活动地块区运动与变形特征的数值模拟[J].大地测量与地球动力学,26(2):15—23.WANG Hui,ZHANG Guo-min,SHI Yao-lin,et al.2006.Numerical simulation of movement and deformation of Qing-hai-Tibet Plateau[J].Journal of Geodesy and Geodynamics,26(2):15—23(in Chinese).
徐锡伟,陈文彬,于贵华,等.2002.2001年11月14日昆仑山库塞湖地震(MS8.1)地表破裂带的基本特征[J].地震地质,24(1):1—13.XU Xi-wei,CHEN Wen-bin,YU Gui-hua,et al.2002.Characteristic features of the surface ruptures of the Hoh SaiHu(Kunlunshan)earthquake(MS8.1),northern Tibetan Plateau,China[J].Seismology and Geology,24(1):1—13(in Chinese).
许立生,陈运泰.2004.从全球长周期波形资料反演2001年11月14日昆仑山口地震时空破裂过程[J].中国科学(D辑),34(3):256—264.XULi-sheng,CHENYun-tai.2004.Temporal and spatial rupture process of the Kunlun ShanMS8.1earthquake fromglobal long-period waveform data[J].Science in China(Ser D),34(3):256—264(in Chinese).
曾海容,宋惠珍.1999.用双节点有限单元模拟渗流模型中的断裂与裂隙[J].地震地质,21(3):238—242.ZENG Hai-rong,SONG Hui-zhen.1999.Application of double-node finite element on seepage involving fault and frac-ture[J].Seismology and Geology,21(3):238—242(in Chinese).
张国民,马宏生,王辉,等.2005.中国大陆活动地块边界带与强震活动[J].地球物理学报,48(3):602—610.ZHANG Guo-min,MA Hong-sheng,WANG Hui,et al.2005.Boundaries between active-tectonic blocks and strongearthquakes in the China mainland[J].Chinese J Geophys,48(3):602—610(in Chinese).
张国民,田勤俭,王辉.2003.可可西里-东昆仑活动构造带强震活动研究[J].地学前缘,10(1):39—48.ZHANG Guo-min,TIAN Qin-jian,WANG Hui.2003.Strong earthquake activities in Kekexili-east Kunlun mountainsactive fault zone,Northwest China[J].Earth Science Frontiers,10(1):39—48(in Chinese).
张培震,邓起东,张国民,等.2003.中国大陆的强震活动与活动地块[J].中国科学(D辑),33(增刊):12—20.ZHANG Pei-zhen,DENG Qi-dong,ZHANG Guo-min,et al.2003.Active tectonic blocks and strong earthquakes inthe continent of China[J].Science in China(Ser D),46(Suppl):13—24.
Harris R A.1998.Introduction to special section:Stress triggers,stress shadows,and implications for seismic hazard[J].J Geophys Res,103:24347—24358.
Okada Y.1992.Internal deformation due to shear and tensile faults in a half-space[J].Bull Seism Soc Am,82:1018—1040.
Stein R S.1999.The role of stress transfer in earthquake occurrence[J].Nature,402:605—609.
Xu X,Yu G,Klinger Y,et al.2006.Reevaluation of surface rupture parameters and faulting segmentation of the2001Kunlunshan earthquake(MW7.8),northern Tibetan Plateau,China[J].J Geophys Res,111,B05316,doi∶10.1029/2004JB003488.
Zhao S,Muller R D,Takahashi Y,et al.2004.3-D finite-element modeling of deformation and stress associated withfaulting:effect of inhomogeneous crustal structures[J].Geophy J Int,157∶629—644.
郭良迁,张祖胜,李延兴,等.2004.昆仑山口西MS8.1级地震的形变应变场研究[J].地球物理学报,47(6):1068—1075.GUO Liang-qian,ZHANG Zu-sheng,LI Yan-xing,et al.2004.A study on the strain field associated with theMS=8.1Kunlunshan earthquake[J].Chinese J Geophys,47(6):1068—1075(in Chinese).
郝平,傅征祥,田勤俭,等.2004.昆仑山口西8.1级地震强余震库仑破裂应力触发研究[J].地震学报,26(1):30—37.HAO Ping,FUZheng-xiang,TIANQin-jian,et al.2004.Large aftershocks triggered by Coulomb failure stress follow-ing the2001MS8.1great Kunlun earthquake[J].Acta Seismologica Sinica,26(1):30—37(in Chinese).
李延兴,杨国华,李智,等.2003.中国大陆活动地块的运动与应变状态[J].中国科学(D辑),33(增刊):65—81.LI Yan-xing,YANG Guo-hua,LI Zhi,et al.2003.Movement and strain of active blocks in Chinese mainland[J].Sci-ence in China(Ser D),33(Suppl):65—81(in Chinese).
乔学军,王琪,杜瑞林,等.2002昆仑山口西MS8.1地震的地壳变形特征[J].大地测量与地球动力学,22(4):6—11.QIAO Xue-jun,WANG Qi,DU Rui-lin,et al.2002.Characteristics of crustal deformation relating toMS8.1Kunlun-shan earthquake[J].Journal of Geodesy and Geodynamics,22(4):6-11(in Chinese).
任金卫,王敏.2005.GPS观测的2001年昆仑山口西MS8.1级地震地壳变形[J].第四纪研究,25(1):34—44.REN Jin-wei,WANG Min.2005.GPS measured crustal deformation of theMS8.1Kunlun earthquake on November14th2001in Qinghai-Xizang plateau[J].Quaternary Sciences,25(1):34—44(in Chinese).
单新建,柳稼航,马超.2004.2001年昆仑山口西8.1级地震同震形变场特征的初步分析[J].地震学报,26(5):474—480.SHAN Xin-jian,LIU Jia-hang,MA Chao.2004.Preliminary analysis on characteristics of coseismic deformation asso-ciated withMS8.1western Kunlunshan pass earthquake in2001[J].Acta Seismologica Sinica,26(5):474—480(in Chinese).
沈正康,万永革,甘卫军,等.2003.东昆仑活动断裂带大地震之间的黏弹性应力触发研究[J].地球物理学报,46(6):786—795.SHEN Zheng-kang,WAN Yong-ge,GAN Wei-jun,et al.2003.Viscoelastic triggering among large earthquakes alongthe east Kunlun fault system[J].Chinese J Geophys,46(6):786—795(in Chinese).
王辉,张国民,石耀霖,等.2006.青藏活动地块区运动与变形特征的数值模拟[J].大地测量与地球动力学,26(2):15—23.WANG Hui,ZHANG Guo-min,SHI Yao-lin,et al.2006.Numerical simulation of movement and deformation of Qing-hai-Tibet Plateau[J].Journal of Geodesy and Geodynamics,26(2):15—23(in Chinese).
徐锡伟,陈文彬,于贵华,等.2002.2001年11月14日昆仑山库塞湖地震(MS8.1)地表破裂带的基本特征[J].地震地质,24(1):1—13.XU Xi-wei,CHEN Wen-bin,YU Gui-hua,et al.2002.Characteristic features of the surface ruptures of the Hoh SaiHu(Kunlunshan)earthquake(MS8.1),northern Tibetan Plateau,China[J].Seismology and Geology,24(1):1—13(in Chinese).
许立生,陈运泰.2004.从全球长周期波形资料反演2001年11月14日昆仑山口地震时空破裂过程[J].中国科学(D辑),34(3):256—264.XULi-sheng,CHENYun-tai.2004.Temporal and spatial rupture process of the Kunlun ShanMS8.1earthquake fromglobal long-period waveform data[J].Science in China(Ser D),34(3):256—264(in Chinese).
曾海容,宋惠珍.1999.用双节点有限单元模拟渗流模型中的断裂与裂隙[J].地震地质,21(3):238—242.ZENG Hai-rong,SONG Hui-zhen.1999.Application of double-node finite element on seepage involving fault and frac-ture[J].Seismology and Geology,21(3):238—242(in Chinese).
张国民,马宏生,王辉,等.2005.中国大陆活动地块边界带与强震活动[J].地球物理学报,48(3):602—610.ZHANG Guo-min,MA Hong-sheng,WANG Hui,et al.2005.Boundaries between active-tectonic blocks and strongearthquakes in the China mainland[J].Chinese J Geophys,48(3):602—610(in Chinese).
张国民,田勤俭,王辉.2003.可可西里-东昆仑活动构造带强震活动研究[J].地学前缘,10(1):39—48.ZHANG Guo-min,TIAN Qin-jian,WANG Hui.2003.Strong earthquake activities in Kekexili-east Kunlun mountainsactive fault zone,Northwest China[J].Earth Science Frontiers,10(1):39—48(in Chinese).
张培震,邓起东,张国民,等.2003.中国大陆的强震活动与活动地块[J].中国科学(D辑),33(增刊):12—20.ZHANG Pei-zhen,DENG Qi-dong,ZHANG Guo-min,et al.2003.Active tectonic blocks and strong earthquakes inthe continent of China[J].Science in China(Ser D),46(Suppl):13—24.
Harris R A.1998.Introduction to special section:Stress triggers,stress shadows,and implications for seismic hazard[J].J Geophys Res,103:24347—24358.
Okada Y.1992.Internal deformation due to shear and tensile faults in a half-space[J].Bull Seism Soc Am,82:1018—1040.
Stein R S.1999.The role of stress transfer in earthquake occurrence[J].Nature,402:605—609.
Xu X,Yu G,Klinger Y,et al.2006.Reevaluation of surface rupture parameters and faulting segmentation of the2001Kunlunshan earthquake(MW7.8),northern Tibetan Plateau,China[J].J Geophys Res,111,B05316,doi∶10.1029/2004JB003488.
Zhao S,Muller R D,Takahashi Y,et al.2004.3-D finite-element modeling of deformation and stress associated withfaulting:effect of inhomogeneous crustal structures[J].Geophy J Int,157∶629—644.
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