唐山地震序列应力触发的粘弹性力学模型研究
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摘要
根据前人对唐山地震破裂分布、地壳波速和粘性结构的研究,考虑局部应力场、孔隙流体压力和断层附近软介质的影响,计算了唐山地震产生的,投影到后续大余震断层面和滑动方向上的库仑破裂应力变化.结果表明,随后发生的滦县地震和宁河地震均发生在唐山地震产生的库仑破裂应力变化为正的区域.为研究唐山地震、滦县地震和宁河地震对后续小震的触发作用。根据前人对该地区构造应力场和地震破裂分布的研究,假定构造应力量值为10 MPa。求得了震源附近各处可能的小震震源机制.将上述3次地震产生的应力变化投影到可能的小震破裂面和滑动方向上.发现唐山地震、滦县地震和宁河地震产生的正库仑破裂应力变化的"蝴蝶"形分布与后续小震发生的空间分布具有较好的一致性.95%的余震发生在库仑破裂应力变化增加的区域,说明唐山地震序列中前面的大震对后续小震的发生起到了调制作用.该研究结果对大震后余震的危险性快速评估具有一定意义.如果大地震发生后能够快速确定详细的破裂分布和震源区域详细断层及滑动特性资料,本文方法可用来预测未来大余震的发震位置.
We calculated the Coulomb failure stress change generated by the 1976 Tangshan earthquake and projected the stress change onto the fault planes in slip directions of the large follow-up aftershocks.A visco-elastic media is as- sumed in the model.Results of previous studies on co-seismic slip distribution of the Tangshan earthquake,and on crustal velocity and viscosity structures, are used for constraining the model.Effect of the local pore fluid pressure and impact of soft medium near the fault are also considered.Our result shows that the subsequent Luanxian and Ninghe aftershock occurred in the region of in- creased Coulomb failure stress produced by the Tangshan mainshock.To study the triggering effect of the Tangshan,Luanxian,and Ninghe earthquakes to the follow-up small earthquakes,we firstly evaluated the possible focal mechanisms of small earthquakes according to the regional stress field and co-seismic slip distributions derived from previous studies,and assumed a regional tectonic shear stress of 10 MPa.By projecting the stress changes generated by the above three earthquakes to the possible fault planes in slip directions of small earth- quakes,we found that the "butterfly" distribution pattern of increased Coulomb failure stress is consistent with the spatial distribution of follow-up aftershocks, with 95% of them occurred in the region of increased Coulomb failure stress. This result indicates that the former large earthquakes modulated occurrences of follow-up earthquakes in the Tangshan earthquake sequence.This result is of some significance in rapid assessment of aftershock hazard after a large earth- quake.If detailed co-seismic slip distribution on a seismogenic fault and the me- chanical feature of nearby faults can be rapidly determined after a large earth- quake,our approach may be used to predict the locations of large aftershocks.
We calculated the Coulomb failure stress change generated by the 1976 Tangshan earthquake and projected the stress change onto the fault planes in slip directions of the large follow-up aftershocks.A visco-elastic media is as- sumed in the model.Results of previous studies on co-seismic slip distribution of the Tangshan earthquake,and on crustal velocity and viscosity structures, are used for constraining the model.Effect of the local pore fluid pressure and impact of soft medium near the fault are also considered.Our result shows that the subsequent Luanxian and Ninghe aftershock occurred in the region of in- creased Coulomb failure stress produced by the Tangshan mainshock.To study the triggering effect of the Tangshan,Luanxian,and Ninghe earthquakes to the follow-up small earthquakes,we firstly evaluated the possible focal mechanisms of small earthquakes according to the regional stress field and co-seismic slip distributions derived from previous studies,and assumed a regional tectonic shear stress of 10 MPa.By projecting the stress changes generated by the above three earthquakes to the possible fault planes in slip directions of small earth- quakes,we found that the "butterfly" distribution pattern of increased Coulomb failure stress is consistent with the spatial distribution of follow-up aftershocks, with 95% of them occurred in the region of increased Coulomb failure stress. This result indicates that the former large earthquakes modulated occurrences of follow-up earthquakes in the Tangshan earthquake sequence.This result is of some significance in rapid assessment of aftershock hazard after a large earth- quake.If detailed co-seismic slip distribution on a seismogenic fault and the me- chanical feature of nearby faults can be rapidly determined after a large earth- quake,our approach may be used to predict the locations of large aftershocks.
引文
陈运泰，黄立人．林邦慧，刘妙龙，王新华．1979．利用大地测量资料反演的1976年唐山地震的位错模式[J]．地球物理学报，22(3)：201-217．
李志才，许才军．赵少荣．温扬茂．2005．基于地壳分层的唐山地震断层震后变形分析[J]．地球物理学进展，20(4)：961-968．
刘桂萍，傅征祥．2000．1976年7月28日唐山7．8级地震触发的区域地震活动和静应力场变化[J]．地震学报，22(1)：17-26．
刘昌铨，嘉世旭．1986．唐山地震区地壳上地幔结构特征：二维非均匀介质中理论地震图理论地震图计算和结果分析[J]．地震学报，8(4)：341-353．
邱群．1976．1976年7月28日河北省唐山7．8级地震的发震背景及其活动性[J]．地球物理学报，19(4)：259-269．
沈正康，万永革，甘卫军．曾跃华，任群．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．
孙荀英．刘激扬，王仁．1994．1976年唐山地震震时和震后变形的模拟[J]．地球物理学报，37(1)：45-55．
万永革．吴忠良，周公威，黄静．2000．几次复杂地震中不同破裂事件之间的“应力触发”问题[J]．地震学报，22(6)：568-576．
万永革．沈正康，刁桂苓，王福昌，胡新亮，盛书中．2008．利用小震分布和区域应力场确定大震断层面参数方法及其在唐山地震序列中的应用[J]．地球物理学报，51(3)；793-804．
万永革，沈正康，尚丹．2006．2005年10月巴基斯坦M_(?)7．6地震对余震的触发研究[J]．中国地震，22(3)，277-286．
万永革，沈正康，曾跃华，盛书中．2007．青藏高原东北部的库仑应力积累演化对大地震发生的影响[J]．地震学报，29(2)：115-129．
许忠淮．1985．用滑动方向拟合法反演唐山余震区的应力场[J]．地震学报，7(4)：359-362．
于湘伟．陈运泰，王培德．2003．京津唐地区中上地壳三维P波速度结构[J]．地震学报，25(1)：1-14．
曾融生，张少泉，周海南，何正勤．1985．唐山地震区的地壳结构及大陆地震成因的探讨[J]．地震学报，7(2)：125- 142．
张学民，束沛镒，刁桂苓，夏乱保，武有文，李光，王玉珍，张学文．2001．利用数字地震记录研究唐山震区台下的P、S波速度结构[J]．华北地震科学，19(1)：10-17．
张之立，李钦祖．谷继成，靳雅敏，杨懋源，刘万琴．1980．唐山地震的破裂过程及其力学分析[J]．地震学报，2(2)：111-129．
张祖胜．1982．地形变背景与异常分析[C]//国家地震局《一九七六年唐山地震》编写组编．一九七六年唐山地震．北京：地震出版社：131-170．
郑天愉，姚振兴．1993．用近场记录研究唐山地震的震源过程[J]．地球物理学报，36(2)：174-184．
周慧兰．1985．浅源走滑大震震源过程的某些特征[J]．地球物理学报．28(6)：579—587．
Ben-Zion Y,Rice J R,Dmowska R.1993.Interaction of the San Andreas fault creeping segment with adjacent great rup- ture zones and earthquake recurrence at Parkfield[J].J Geophys Res,95:2135-2144.
Butler R,Stewart G S,Kanamori H.1979.The July 27,1976 Tangshan,China earthquake:A complex sequence of in- traplate events[J].Bull Seism Soc Amer,69:207-220.
Chen W,Nabelek J.1988.Seismogenic strike-slip faulting and the development of the North China Basin[J].Tectonics, 7:975-989.
Cocco M,Rice J R.2002.Pore pressure and poroelasticity effects in Coulomb stress analysis of earthquake interactions [J].J Geophys Res,107(B2):ESE2-1-17.
Das S,Scholz C.1981.Off-fault aftershock clusters caused by shear stress increase?[J].Bull Seism Soc Amer,71: 1669-1675.
Freed A M,Lin J.2001.Delayed triggering of the 1999 Hector Mine earthquake by viscoelastic stress transfer[J].Na- ture,411:180-183.
Harris R A.1998.Introduction to special section:Stress triggers,stress shadows,and implications for seismic hazard [J].J Geophys Res,103,24347-24358.
Huang B,Yeh Y T.1997.The fault ruptures of the 1976 Tanghsan earthquake sequence inferred from coseismic crustal deformation[J].Bull Seism Soc Amer,87:1046-1057.
Kikuchi M,Kanamori H.1986.Inversion of complex body wavesⅡ[J].Phys Earth Planet Interi,43:205-222.
King G C P,Stein R S,Lin J.1994.Static stress changes and the triggering of earthquakes[J].Bull Seism Soc Amer, 84:935-953.
Li Y G,Leary P C,Aki K,Malin P.1990.Seismic trapped modes in the Oroville and San Andreas fault zones[J].Sci- ence,249:763-766.
Li Y G,Aki K,Vidale J,Li W H K,Marone C J.1994.Fine structure of the Landers fault zone:Segmentation and the rupture process[J].Science,265:367-380,DOI 10.1126/science.265.5170.367.
Ma K,Chan C.2005.Response of seismicity of Coulomb stress triggers and shallows of the 1999 M_(?)=7.6 Chi-Chi,Tai- wan,earthquake[J].J Geophys Res,110:B05S19,doi:10.1029/2004JB003389.
Nalbant S S,Hubert A,King G C P.1998.Stress coupling between earthquakes in northwest Turkey and the north Ae- gean Sea[J].J Geophys Res,103:24469-24486.
Nabelek J,Chen W P,Ye H.1987.The Tangshan earthquake sequence and its implications for the evolution of the North China basin[J].J Geophys Res,92:12 615-12 628.
Nut A,Booker J R.1972.Aftershocks caused by pore fluid flow?[J].Science,175:885-887.
Nut A,Mavko G.1974.Postseismic viscoelastic rebound[J].Science,183:204-206.
Okada Y.1992.Internal deformation due to shear and tensile faults in a half-space[J].Bull Seism Soc Amer,82: 1018-1040.
Piombo A,Martinelli G,Dragoni M.2005.Post-seismic fluid flow and Coulomb stress changes in a poroelastic medium [J].Geophys J Int,162:507-515.
Pollitz F F.1992.Postseismic relaxation theory on the spherical earth[J].Bull Saism Soc Amer,82:422-453.
Pollitz F F,Sacks I S.1997.The 1995 Kobe,Japan,earthquake:A long-delayed aftershock of the offshore 1944 Tonan- kai and 1946 Nankaido earthquakes[J].Bull Seism Soc Amer,87:1-10.
Pollitz F F,Schwartz D P.2008.Probabilistic seismic hazard in the San Francisco Bay area based on a simplified viscoelas- tic cycle model of fault interactions[J].J Geophys Res,113..1305409,doi:10.1029/2007JB005227.
Rice J R.1992.Fault stress states,pore pressure distributions and the weakness of the San Andreas fault[C]//Evans B, Wong T-F eds.Fault Mechanics and Transport Properties of Rock.Academic,San Diego,Calif,475-503.
Robinson R,Zhou S.2005.Stress interactions within the Tangshan,China,earthquake sequence of 1976[J].Bull Seism Soc Amer,95(6):2 501-2 505.
Rydelek P A,Sacks I S.1990.Asthenospheric viscosity and stress diffusion:A mechanism to explain correlated earth- quakes and surface deformation in NE Japan[J].Geophys J Int,100:39-58.
Seeber L,Ambruater J G,Kim W Y,Scharnberger C,Barstow N.1998.The 1994 Cacoosing Valley earthquakes near Reading,Pennsylvania:A shollow rupture triggered by quarry unloading[J].J Geophys Res,103:24 505-24 521.
Shedlock K,Baranowski J,Xiao W,Hu X L.1987.The Tangshan aftershock sequence[J].J Geophys Res,92: 2791-2803.
Stein R S.1999.The role of stress transfer in earthquake occurrence[J].Nature,402:605-609.
Troise C,De Natale G,Pingue F,Petrazzuoli S M.1998.Evidence for static stress interaction among earthquakes in south-central Apennines(Italy)[J].Geophys J Int,134:809-817.
Toda S,Stein R S,Reasenberg P A,Dieterich J H,Yoshid A.1998.Stress transferred by the 1995 M_(?)=6.9 Kobe,Ja- pan,shock:Effect on aftershocks and future earthquake probabilities[J].J Geophys Res,103:24 543-24 565.
US Geological Survey,Southern California Earthquake Center,California Division of Mines and Geology.2000.Prelimi- nary report on the 16 October 1999 M7.1 Hector Mine,California,earthquake[J].Seismol Res Lett,71:11-23.
Wald D J,Heaton T H.1994.Spatial and temporal distribution of slip for the 1992 Landers,California earthquake[J]. Bull Seism Soc Amer,84:668-691.
Xie X B,Yap Z X.1991.The faulting process of Tangshan earthquake inverted simultaneously from teleseismic wave- forms and geodetic deformation[J].Phys Earth Planet Interi,661 265-277.
Xu Z H,Wang S Y.1986.A possible change in stress field orientation due to the 1976 Tangshan earthquake[J].Pure Appl Geophss,51:139-154.
Zeng Y.2001.Viscoelastic stress-triggering of the 1999 Hector Mine earthquake by the 1992 Landers earthquake[J]. Geophys Res Lett,28:3007-3010.
李志才，许才军．赵少荣．温扬茂．2005．基于地壳分层的唐山地震断层震后变形分析[J]．地球物理学进展，20(4)：961-968．
刘桂萍，傅征祥．2000．1976年7月28日唐山7．8级地震触发的区域地震活动和静应力场变化[J]．地震学报，22(1)：17-26．
刘昌铨，嘉世旭．1986．唐山地震区地壳上地幔结构特征：二维非均匀介质中理论地震图理论地震图计算和结果分析[J]．地震学报，8(4)：341-353．
邱群．1976．1976年7月28日河北省唐山7．8级地震的发震背景及其活动性[J]．地球物理学报，19(4)：259-269．
沈正康，万永革，甘卫军．曾跃华，任群．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．
孙荀英．刘激扬，王仁．1994．1976年唐山地震震时和震后变形的模拟[J]．地球物理学报，37(1)：45-55．
万永革．吴忠良，周公威，黄静．2000．几次复杂地震中不同破裂事件之间的“应力触发”问题[J]．地震学报，22(6)：568-576．
万永革．沈正康，刁桂苓，王福昌，胡新亮，盛书中．2008．利用小震分布和区域应力场确定大震断层面参数方法及其在唐山地震序列中的应用[J]．地球物理学报，51(3)；793-804．
万永革，沈正康，尚丹．2006．2005年10月巴基斯坦M_(?)7．6地震对余震的触发研究[J]．中国地震，22(3)，277-286．
万永革，沈正康，曾跃华，盛书中．2007．青藏高原东北部的库仑应力积累演化对大地震发生的影响[J]．地震学报，29(2)：115-129．
许忠淮．1985．用滑动方向拟合法反演唐山余震区的应力场[J]．地震学报，7(4)：359-362．
于湘伟．陈运泰，王培德．2003．京津唐地区中上地壳三维P波速度结构[J]．地震学报，25(1)：1-14．
曾融生，张少泉，周海南，何正勤．1985．唐山地震区的地壳结构及大陆地震成因的探讨[J]．地震学报，7(2)：125- 142．
张学民，束沛镒，刁桂苓，夏乱保，武有文，李光，王玉珍，张学文．2001．利用数字地震记录研究唐山震区台下的P、S波速度结构[J]．华北地震科学，19(1)：10-17．
张之立，李钦祖．谷继成，靳雅敏，杨懋源，刘万琴．1980．唐山地震的破裂过程及其力学分析[J]．地震学报，2(2)：111-129．
张祖胜．1982．地形变背景与异常分析[C]//国家地震局《一九七六年唐山地震》编写组编．一九七六年唐山地震．北京：地震出版社：131-170．
郑天愉，姚振兴．1993．用近场记录研究唐山地震的震源过程[J]．地球物理学报，36(2)：174-184．
周慧兰．1985．浅源走滑大震震源过程的某些特征[J]．地球物理学报．28(6)：579—587．
Ben-Zion Y,Rice J R,Dmowska R.1993.Interaction of the San Andreas fault creeping segment with adjacent great rup- ture zones and earthquake recurrence at Parkfield[J].J Geophys Res,95:2135-2144.
Butler R,Stewart G S,Kanamori H.1979.The July 27,1976 Tangshan,China earthquake:A complex sequence of in- traplate events[J].Bull Seism Soc Amer,69:207-220.
Chen W,Nabelek J.1988.Seismogenic strike-slip faulting and the development of the North China Basin[J].Tectonics, 7:975-989.
Cocco M,Rice J R.2002.Pore pressure and poroelasticity effects in Coulomb stress analysis of earthquake interactions [J].J Geophys Res,107(B2):ESE2-1-17.
Das S,Scholz C.1981.Off-fault aftershock clusters caused by shear stress increase?[J].Bull Seism Soc Amer,71: 1669-1675.
Freed A M,Lin J.2001.Delayed triggering of the 1999 Hector Mine earthquake by viscoelastic stress transfer[J].Na- ture,411:180-183.
Harris R A.1998.Introduction to special section:Stress triggers,stress shadows,and implications for seismic hazard [J].J Geophys Res,103,24347-24358.
Huang B,Yeh Y T.1997.The fault ruptures of the 1976 Tanghsan earthquake sequence inferred from coseismic crustal deformation[J].Bull Seism Soc Amer,87:1046-1057.
Kikuchi M,Kanamori H.1986.Inversion of complex body wavesⅡ[J].Phys Earth Planet Interi,43:205-222.
King G C P,Stein R S,Lin J.1994.Static stress changes and the triggering of earthquakes[J].Bull Seism Soc Amer, 84:935-953.
Li Y G,Leary P C,Aki K,Malin P.1990.Seismic trapped modes in the Oroville and San Andreas fault zones[J].Sci- ence,249:763-766.
Li Y G,Aki K,Vidale J,Li W H K,Marone C J.1994.Fine structure of the Landers fault zone:Segmentation and the rupture process[J].Science,265:367-380,DOI 10.1126/science.265.5170.367.
Ma K,Chan C.2005.Response of seismicity of Coulomb stress triggers and shallows of the 1999 M_(?)=7.6 Chi-Chi,Tai- wan,earthquake[J].J Geophys Res,110:B05S19,doi:10.1029/2004JB003389.
Nalbant S S,Hubert A,King G C P.1998.Stress coupling between earthquakes in northwest Turkey and the north Ae- gean Sea[J].J Geophys Res,103:24469-24486.
Nabelek J,Chen W P,Ye H.1987.The Tangshan earthquake sequence and its implications for the evolution of the North China basin[J].J Geophys Res,92:12 615-12 628.
Nut A,Booker J R.1972.Aftershocks caused by pore fluid flow?[J].Science,175:885-887.
Nut A,Mavko G.1974.Postseismic viscoelastic rebound[J].Science,183:204-206.
Okada Y.1992.Internal deformation due to shear and tensile faults in a half-space[J].Bull Seism Soc Amer,82: 1018-1040.
Piombo A,Martinelli G,Dragoni M.2005.Post-seismic fluid flow and Coulomb stress changes in a poroelastic medium [J].Geophys J Int,162:507-515.
Pollitz F F.1992.Postseismic relaxation theory on the spherical earth[J].Bull Saism Soc Amer,82:422-453.
Pollitz F F,Sacks I S.1997.The 1995 Kobe,Japan,earthquake:A long-delayed aftershock of the offshore 1944 Tonan- kai and 1946 Nankaido earthquakes[J].Bull Seism Soc Amer,87:1-10.
Pollitz F F,Schwartz D P.2008.Probabilistic seismic hazard in the San Francisco Bay area based on a simplified viscoelas- tic cycle model of fault interactions[J].J Geophys Res,113..1305409,doi:10.1029/2007JB005227.
Rice J R.1992.Fault stress states,pore pressure distributions and the weakness of the San Andreas fault[C]//Evans B, Wong T-F eds.Fault Mechanics and Transport Properties of Rock.Academic,San Diego,Calif,475-503.
Robinson R,Zhou S.2005.Stress interactions within the Tangshan,China,earthquake sequence of 1976[J].Bull Seism Soc Amer,95(6):2 501-2 505.
Rydelek P A,Sacks I S.1990.Asthenospheric viscosity and stress diffusion:A mechanism to explain correlated earth- quakes and surface deformation in NE Japan[J].Geophys J Int,100:39-58.
Seeber L,Ambruater J G,Kim W Y,Scharnberger C,Barstow N.1998.The 1994 Cacoosing Valley earthquakes near Reading,Pennsylvania:A shollow rupture triggered by quarry unloading[J].J Geophys Res,103:24 505-24 521.
Shedlock K,Baranowski J,Xiao W,Hu X L.1987.The Tangshan aftershock sequence[J].J Geophys Res,92: 2791-2803.
Stein R S.1999.The role of stress transfer in earthquake occurrence[J].Nature,402:605-609.
Troise C,De Natale G,Pingue F,Petrazzuoli S M.1998.Evidence for static stress interaction among earthquakes in south-central Apennines(Italy)[J].Geophys J Int,134:809-817.
Toda S,Stein R S,Reasenberg P A,Dieterich J H,Yoshid A.1998.Stress transferred by the 1995 M_(?)=6.9 Kobe,Ja- pan,shock:Effect on aftershocks and future earthquake probabilities[J].J Geophys Res,103:24 543-24 565.
US Geological Survey,Southern California Earthquake Center,California Division of Mines and Geology.2000.Prelimi- nary report on the 16 October 1999 M7.1 Hector Mine,California,earthquake[J].Seismol Res Lett,71:11-23.
Wald D J,Heaton T H.1994.Spatial and temporal distribution of slip for the 1992 Landers,California earthquake[J]. Bull Seism Soc Amer,84:668-691.
Xie X B,Yap Z X.1991.The faulting process of Tangshan earthquake inverted simultaneously from teleseismic wave- forms and geodetic deformation[J].Phys Earth Planet Interi,661 265-277.
Xu Z H,Wang S Y.1986.A possible change in stress field orientation due to the 1976 Tangshan earthquake[J].Pure Appl Geophss,51:139-154.
Zeng Y.2001.Viscoelastic stress-triggering of the 1999 Hector Mine earthquake by the 1992 Landers earthquake[J]. Geophys Res Lett,28:3007-3010.
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