2008年汶川地震近断裂区域变形场的空间分布
|
摘要
应用Yoshimitsu Okada及Steketee静态断裂位错模型及目前汶川地震研究成果,理论上反演龙门山近断裂区域在汶川地震中从震源深处至地表的变形(应变)场分布.通过矢量合成及坐标变换方法将Yoshimitsu Okada单一静态断裂位错模型应用于龙门山断裂带错裂研究中,重点研究汶川地震中因龙门山中央主断裂中、北段和山前断裂中段共同错动形成的应变场.模拟揭示了应变场平面和垂直分量的空间分布特征.研究发现:应变场垂直分量的幅值在震源深处大于地表,但在地表分布范围较大;应变场沿断裂走向分量的幅值和影响范围由震源深度至地表均逐渐增加;应变场垂直于断裂走向分量的变化情况类似于垂直向应变场;震源深度附近的大变形可能为龙门山断裂在地震中强烈挤压形成的塑性变形.研究表明从震源至地表,所有应变场分量从断裂两侧附近位置至远离断裂,幅值均迅速衰减;其中地表部分的最大变形与现有计算成果近似,变形场的变化特征与地表科考近似,断裂两盘变形方向与震后InSAR资料揭示的情况一致.
Based on the Yoshimitsu Okada and Steketee s dislocation model and present achievements of scientific researches on Wenchuan earthquake,we theoretically compute the distribution of deformation (strain) fields from the focal depth to ground surface in the region near the Longmenshan faults belt.Through the vector synthesis and coordinate transformation method,we expand Okada s single static dislocation model to the research of Longmenshan faults belt,specially the deformation fields caused by the slide motion of middle and north part of central segment and middle part of foreland segment of Longmenshan fault belt in Wenchuan earthquake.The research shows the spatial distribution features of level and vertical components of deformation fields.Through the simulation,we find that the vertical component of strain field is greater in magnitude but smaller in scope at the focus than that on the ground surface,the strain component along the strike direction increases gradually in both magnitude and influencing scope from focal depth to ground surface,and the variation of strain component perpendicular to the fault strike is similar to that of the vertical component. The large deformation near the focus perhaps stems from the plasticity.Moreover,our simulation also shows the variation of strain field with the distance to the fault outcrop.The simulation result on the ground surface agrees with the present scientific research.At last,by comparing with InSAR observation data,the deformation direction obtained by simulation agrees with the observation data.
Based on the Yoshimitsu Okada and Steketee s dislocation model and present achievements of scientific researches on Wenchuan earthquake,we theoretically compute the distribution of deformation (strain) fields from the focal depth to ground surface in the region near the Longmenshan faults belt.Through the vector synthesis and coordinate transformation method,we expand Okada s single static dislocation model to the research of Longmenshan faults belt,specially the deformation fields caused by the slide motion of middle and north part of central segment and middle part of foreland segment of Longmenshan fault belt in Wenchuan earthquake.The research shows the spatial distribution features of level and vertical components of deformation fields.Through the simulation,we find that the vertical component of strain field is greater in magnitude but smaller in scope at the focus than that on the ground surface,the strain component along the strike direction increases gradually in both magnitude and influencing scope from focal depth to ground surface,and the variation of strain component perpendicular to the fault strike is similar to that of the vertical component. The large deformation near the focus perhaps stems from the plasticity.Moreover,our simulation also shows the variation of strain field with the distance to the fault outcrop.The simulation result on the ground surface agrees with the present scientific research.At last,by comparing with InSAR observation data,the deformation direction obtained by simulation agrees with the observation data.
引文
[1] Steketee J A. On Voherra's dislocations in a semi-infinite elastic medium. Can. J. Phys.，1958, 36:192-205
[2] Chinnery M A. The deformation of the ground around surface faults. Bull. Seism. Soc. Am.，1961，51:355-372
[3] Chinnery M A. The stress changes that accompany strike-slip faulting. Bull. Seism. Soc. Am.，1963, 53:921-932
[4] Mansinha L, Smylie D E. Effect of earthquakes on the Chandler wobble and the secular polar shift. J. Geophys. Re.s.,1967，72: 4731-4743
[5] Mansinha L, Smylie D E. The displacement fields of inclined faults. Bull. Seism. Soc. Am.，1971，61:1433-1440
[6] Converse G. Equations far the displacements and displacement derivatives due to a rectangulardislocation in a three-dimensional elastic half-space.User' s Manual For DIS3D. Menlo Park; U. S. Geological Survey, 1973. 119-148
[7] Iwasaki T, Sato R. Strain field in a semi-infinite medium due to an inclined rectangular fault. J. Phy,r. Earth, 1979, 27; 285-314
[8] Okada Y. Surface deformation due to shear and tensile faults in a half-space. Bull. Seism. Soc. Am.，1985，75:1135-1154
[9] Okada Y. Internal deformation due to shear and tensile faults in a half-space. Bull. Seism. Soc. Am.，1992, 82: 1018-1040
[10] 陈运泰，林邦慧，林中洋等.根据地面形变的观测研究1966年邢台地震的震源过程.地球物理学报，1975, 18(3): 164-182 Chen Y T, Lin B H, Lin Z Y, et al. The focal mechanism of the 1966 Hsingtai earthquake as inferred from the ground deformation observations. Chinese J. Geophys. (Acta Geophysica Sinica) Cin Chinese)，1975，18(3):164-182
[11]申重阳，李辉，谈洪波.汶川8.0级地震同震重力与形变效应模拟.大地测量与地球动力学，2008, 28(5) 6～12 Shen C Y, I,i H, Tan H B. Simulation of coseismic gravity changes and deformation effect of Wenchuan MsB. 0 earthquake. Journal o_f Geodesy and Geodynamics(in Chinese)，2008, 28(5):6-12
[12]黄建梁,李辉,李瑞浩.点源位错引起的重力、位势及其梯度变化.地震学报,1995,17(1); 72-80 Huang JI，Li H, Li R H. The variation of gravity potential and gradient due to source dislocation. Acta Seismologica Sinca (in Chinese),1995,17(1):72-80
[13]张永志，赵大江，王卫东.断层走滑不均性对地面变形的影响.地球物理学报,2009, 52(8): 2113-2118 Zhang Y Z, Zhao D J> Wang W D, Effects on the earth surface deformation by asymmetric strike slip on fault plane.Chinese J .Geophys.(in Chinese),2009, 52(8):2113-2118
[14] 张勇，冯万鹏，许力生等.2008年汉川大地震的时空破裂过程.中国科学(D辑-地球科学)，2008, 38(10):1186-1194 Zhang Y, Feng W P, Xu L S, et al. Spatio-temporal rupture process of the 2008 great Wenchuan earthquake. Science in China (Ser I}Earth Sci) (in Chinese)，2008, 38(10):1186-1194
[15]王卫民，赵连锋，李娟等.四川汉川8.0级地震震源过程. 地球物理学报，2008, 51(5): 1403-1410 Wang W M, Zhao L F, Li J，et al. Rupture process of the Ms8. 0 Wenchuan earthquake of Sichuan, China. Chinese J. Geophys. (in Chinese)，2008，51(5):1403-1410
[16]朱守彪，张培震.2008年汉川M,8.0 地震发生过程的动力学机制研究.地球物理学报，2009, 52(2); 418-427 Zhu S B, Zhang P Z. A study on the dynamical mechanisms of the Wenchuan M,,8. 0 earthquake, 2008. Chinese J. Geophys. (in Chinese)，2009，52(2):418-427
[17]唐荣昌，文德华，黄祖智等.松潘-龙门山地区主要活动断 裂带第四纪活动特征.中国地震，1991, 7(3); 6471 Tang R C, Wen D H,Huang Z Z, et al. The Quaternary activity characteristics of several major active faults in the Songpan-Longmenshan region. Earthquake Research in China (in Chinese)，1991，7(3):64-71
[18]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.地震地质，2007, 29(3): 657-673 Chen G G, Ji F J，Zhou R J，et al. Primary research of activity segmentation of Longmenshan Fault zone since late-Quaternary. Seismology and Geology(in Chinese )，2007,29(3):657-673
[19]杨晓平，冯希杰，戈天勇等.龙门山断裂带北段第四纪活动的地质地貌证据.地震地质，2008, 30(3): 644-657 Yang X P, Feng X J，Ge T Y, et al. Geological and geomorphic evidence for the Quaternary activity on the northeast segment of Longmenshan fault zone. Seismology and Geology (in Chinese)，2008, 30(3):644-657
[20]李勇，曾允孚，尹海生.龙门山前陆盆地沉积及构造演化.成都:成都科技大学出版社，1995. 1-91 Li Y, Zeng Y F, Yin H S. Sedimentary and Tectonic Evolution of the Longmenshan Foreland Basin, Western Sichuan, China (in Chinese). Chengdu: Chengdu University of Science and Technology Press, 1995. 1-91
[21]Volterra V. Sur 1'equilibre des corps elastiques multiplement connexcs. Ann Sci Ecole Norm Suf}er. Paris, 1907, 24; 401-517
[22]张永志，罗凌燕，王卫东.位错理论在西安地面沉降模拟中的应用.西北地震学报，2008, 30(1): 17-20 Zhang Y Z, Luo L Y, Wang W D. Computed subsidence by dislocation model in Xi'an City. Northwestern Seismological Journal (in Chinese)，2008, 30(1):17-20
[23] Xu X W, Wen X Z, Yu G H, et al. Coseismic reverse-and oblique-slip surface faulting generated by the 2008 Mw7. 9 Wenchuan earthquake, China. Geology, 2009，37(6):515-518
[24]Shen Z K, Sun J B, Zhang P Z, et al. Slip maxima at fault junctions and rupturing of barriers during the 2008 Wenchuan earthquake. Nature, 2009，2: 718-724
[25]李延兴，张静华，周伟等汉川Ms 8.0地震孕育发生的机制与动力学问题地球物理学报，2009, 52(2) ; 519-530 Li Y X, Zhang J H, Zhou W, et al. The mechanism and dynamics of the generation and occurrence for Wenchuan MSB.Oearthquake. ChzneseJ. Geophys. (in Chinese)，2009, 52(2):519-530
[26]龙学明，罗志立.龙门山造山带的崛起和四川盆地的形成与演化.成都:成都科技大学出版社，1994 Long X M, Luo Z I.Uplift of the Longmenshan Orogenic Belt, and Formation and Evolution of the Sichuan Basin(in Chinese). Chengdu: Chengdu University of Science and Technology Press, 1994
[27]刘静，张智慧，文力等.汶川8.0级大地震同震破裂的特殊性及构造意义一多条平行断裂同时活动的反序型逆冲地震事件.地质学报，2008, 82(12):1707-1722 Liu J，Zhang Z H, Wen L, et al. The Ms 8.0 Wenchuanearthquake co-seismic rupture and its tectonic implications-
an out-of-sequence thrusting event with slip partitioned on multiple faults. Acta Geologica Sinica(in Chinese)，2008,82(12):1707-1722
[28]徐锡伟，闻学泽，叶建青等汉川Ms 8.。地震地表破裂带及其发震构造地震地质，2008, 30(3); 597-629 Xu X W, Wen X Z, Ye J Q, et al. The Ms8.0 Wenchuan earthquake surface ruptures and its seismogenic structure.Seismology and Geology (in Chinese)，2008, 30(3):579-629
[29]陈章立，赵翠萍，王勤彩等汝川Ms8.0级地震发生背景与过程的研究.地球物理学报，2009, 52(2): 455-463 Chen Z L, Zhao C P, Wang Q C, et al. A study on the occurrence background and process of Wenchuan Ms 8. 0 earthquake. Chinese J.Geo ph ys.(in Chinese),2009,52(2):455-463
[30]王绪本，朱迎堂，赵锡奎等.青藏高原东缘龙门山逆冲构造深部电性结构特征.地球物理学报，2009, 52(2): 564-571 Wang X B, Zhu Y T, Zhao X K, et al. Deep conductivity characteristics of the Longmen Shan, Eastern Qinghai-Tibet Plateau. Chinese J. Geophys.(in Chinese)，2009, 52(2):564^-571
[31]万永革.坟川地震产生的应变场和位移场.防灾科技学院学报，2009, 11(1):5-9 Wan Y G. Displacement and strain field caused by Wenchuan earthquake. Jourrml of Institute of Disa.ster}Preverttion Science and Technology (in Chinese)，2009，11(1):5-9
[32]张培震.GPS测定的2008年汉川MsB. 0级地震的同震位移场.中国科学(D辑-地球科学)，2008, 38(10); 1195^-1206 Zhang P Z. The coseismic displacement fields of Wenchuan Ms8.0 earthquake 2008. Science in China (Ser D-Earth Sci)(in Chinese)，2008 38(10):1195-1206
[2] Chinnery M A. The deformation of the ground around surface faults. Bull. Seism. Soc. Am.，1961，51:355-372
[3] Chinnery M A. The stress changes that accompany strike-slip faulting. Bull. Seism. Soc. Am.，1963, 53:921-932
[4] Mansinha L, Smylie D E. Effect of earthquakes on the Chandler wobble and the secular polar shift. J. Geophys. Re.s.,1967，72: 4731-4743
[5] Mansinha L, Smylie D E. The displacement fields of inclined faults. Bull. Seism. Soc. Am.，1971，61:1433-1440
[6] Converse G. Equations far the displacements and displacement derivatives due to a rectangulardislocation in a three-dimensional elastic half-space.User' s Manual For DIS3D. Menlo Park; U. S. Geological Survey, 1973. 119-148
[7] Iwasaki T, Sato R. Strain field in a semi-infinite medium due to an inclined rectangular fault. J. Phy,r. Earth, 1979, 27; 285-314
[8] Okada Y. Surface deformation due to shear and tensile faults in a half-space. Bull. Seism. Soc. Am.，1985，75:1135-1154
[9] Okada Y. Internal deformation due to shear and tensile faults in a half-space. Bull. Seism. Soc. Am.，1992, 82: 1018-1040
[10] 陈运泰，林邦慧，林中洋等.根据地面形变的观测研究1966年邢台地震的震源过程.地球物理学报，1975, 18(3): 164-182 Chen Y T, Lin B H, Lin Z Y, et al. The focal mechanism of the 1966 Hsingtai earthquake as inferred from the ground deformation observations. Chinese J. Geophys. (Acta Geophysica Sinica) Cin Chinese)，1975，18(3):164-182
[11]申重阳，李辉，谈洪波.汶川8.0级地震同震重力与形变效应模拟.大地测量与地球动力学，2008, 28(5) 6～12 Shen C Y, I,i H, Tan H B. Simulation of coseismic gravity changes and deformation effect of Wenchuan MsB. 0 earthquake. Journal o_f Geodesy and Geodynamics(in Chinese)，2008, 28(5):6-12
[12]黄建梁,李辉,李瑞浩.点源位错引起的重力、位势及其梯度变化.地震学报,1995,17(1); 72-80 Huang JI，Li H, Li R H. The variation of gravity potential and gradient due to source dislocation. Acta Seismologica Sinca (in Chinese),1995,17(1):72-80
[13]张永志，赵大江，王卫东.断层走滑不均性对地面变形的影响.地球物理学报,2009, 52(8): 2113-2118 Zhang Y Z, Zhao D J> Wang W D, Effects on the earth surface deformation by asymmetric strike slip on fault plane.Chinese J .Geophys.(in Chinese),2009, 52(8):2113-2118
[14] 张勇，冯万鹏，许力生等.2008年汉川大地震的时空破裂过程.中国科学(D辑-地球科学)，2008, 38(10):1186-1194 Zhang Y, Feng W P, Xu L S, et al. Spatio-temporal rupture process of the 2008 great Wenchuan earthquake. Science in China (Ser I}Earth Sci) (in Chinese)，2008, 38(10):1186-1194
[15]王卫民，赵连锋，李娟等.四川汉川8.0级地震震源过程. 地球物理学报，2008, 51(5): 1403-1410 Wang W M, Zhao L F, Li J，et al. Rupture process of the Ms8. 0 Wenchuan earthquake of Sichuan, China. Chinese J. Geophys. (in Chinese)，2008，51(5):1403-1410
[16]朱守彪，张培震.2008年汉川M,8.0 地震发生过程的动力学机制研究.地球物理学报，2009, 52(2); 418-427 Zhu S B, Zhang P Z. A study on the dynamical mechanisms of the Wenchuan M,,8. 0 earthquake, 2008. Chinese J. Geophys. (in Chinese)，2009，52(2):418-427
[17]唐荣昌，文德华，黄祖智等.松潘-龙门山地区主要活动断 裂带第四纪活动特征.中国地震，1991, 7(3); 6471 Tang R C, Wen D H,Huang Z Z, et al. The Quaternary activity characteristics of several major active faults in the Songpan-Longmenshan region. Earthquake Research in China (in Chinese)，1991，7(3):64-71
[18]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.地震地质，2007, 29(3): 657-673 Chen G G, Ji F J，Zhou R J，et al. Primary research of activity segmentation of Longmenshan Fault zone since late-Quaternary. Seismology and Geology(in Chinese )，2007,29(3):657-673
[19]杨晓平，冯希杰，戈天勇等.龙门山断裂带北段第四纪活动的地质地貌证据.地震地质，2008, 30(3): 644-657 Yang X P, Feng X J，Ge T Y, et al. Geological and geomorphic evidence for the Quaternary activity on the northeast segment of Longmenshan fault zone. Seismology and Geology (in Chinese)，2008, 30(3):644-657
[20]李勇，曾允孚，尹海生.龙门山前陆盆地沉积及构造演化.成都:成都科技大学出版社，1995. 1-91 Li Y, Zeng Y F, Yin H S. Sedimentary and Tectonic Evolution of the Longmenshan Foreland Basin, Western Sichuan, China (in Chinese). Chengdu: Chengdu University of Science and Technology Press, 1995. 1-91
[21]Volterra V. Sur 1'equilibre des corps elastiques multiplement connexcs. Ann Sci Ecole Norm Suf}er. Paris, 1907, 24; 401-517
[22]张永志，罗凌燕，王卫东.位错理论在西安地面沉降模拟中的应用.西北地震学报，2008, 30(1): 17-20 Zhang Y Z, Luo L Y, Wang W D. Computed subsidence by dislocation model in Xi'an City. Northwestern Seismological Journal (in Chinese)，2008, 30(1):17-20
[23] Xu X W, Wen X Z, Yu G H, et al. Coseismic reverse-and oblique-slip surface faulting generated by the 2008 Mw7. 9 Wenchuan earthquake, China. Geology, 2009，37(6):515-518
[24]Shen Z K, Sun J B, Zhang P Z, et al. Slip maxima at fault junctions and rupturing of barriers during the 2008 Wenchuan earthquake. Nature, 2009，2: 718-724
[25]李延兴，张静华，周伟等汉川Ms 8.0地震孕育发生的机制与动力学问题地球物理学报，2009, 52(2) ; 519-530 Li Y X, Zhang J H, Zhou W, et al. The mechanism and dynamics of the generation and occurrence for Wenchuan MSB.Oearthquake. ChzneseJ. Geophys. (in Chinese)，2009, 52(2):519-530
[26]龙学明，罗志立.龙门山造山带的崛起和四川盆地的形成与演化.成都:成都科技大学出版社，1994 Long X M, Luo Z I.Uplift of the Longmenshan Orogenic Belt, and Formation and Evolution of the Sichuan Basin(in Chinese). Chengdu: Chengdu University of Science and Technology Press, 1994
[27]刘静，张智慧，文力等.汶川8.0级大地震同震破裂的特殊性及构造意义一多条平行断裂同时活动的反序型逆冲地震事件.地质学报，2008, 82(12):1707-1722 Liu J，Zhang Z H, Wen L, et al. The Ms 8.0 Wenchuanearthquake co-seismic rupture and its tectonic implications-
an out-of-sequence thrusting event with slip partitioned on multiple faults. Acta Geologica Sinica(in Chinese)，2008,82(12):1707-1722
[28]徐锡伟，闻学泽，叶建青等汉川Ms 8.。地震地表破裂带及其发震构造地震地质，2008, 30(3); 597-629 Xu X W, Wen X Z, Ye J Q, et al. The Ms8.0 Wenchuan earthquake surface ruptures and its seismogenic structure.Seismology and Geology (in Chinese)，2008, 30(3):579-629
[29]陈章立，赵翠萍，王勤彩等汝川Ms8.0级地震发生背景与过程的研究.地球物理学报，2009, 52(2): 455-463 Chen Z L, Zhao C P, Wang Q C, et al. A study on the occurrence background and process of Wenchuan Ms 8. 0 earthquake. Chinese J.Geo ph ys.(in Chinese),2009,52(2):455-463
[30]王绪本，朱迎堂，赵锡奎等.青藏高原东缘龙门山逆冲构造深部电性结构特征.地球物理学报，2009, 52(2): 564-571 Wang X B, Zhu Y T, Zhao X K, et al. Deep conductivity characteristics of the Longmen Shan, Eastern Qinghai-Tibet Plateau. Chinese J. Geophys.(in Chinese)，2009, 52(2):564^-571
[31]万永革.坟川地震产生的应变场和位移场.防灾科技学院学报，2009, 11(1):5-9 Wan Y G. Displacement and strain field caused by Wenchuan earthquake. Jourrml of Institute of Disa.ster}Preverttion Science and Technology (in Chinese)，2009，11(1):5-9
[32]张培震.GPS测定的2008年汉川MsB. 0级地震的同震位移场.中国科学(D辑-地球科学)，2008, 38(10); 1195^-1206 Zhang P Z. The coseismic displacement fields of Wenchuan Ms8.0 earthquake 2008. Science in China (Ser D-Earth Sci)(in Chinese)，2008 38(10):1195-1206
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