以2008年汶川8.0级地震为例分析地震触发的静态库仑应力计算的不确定性
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摘要
人们常用地震产生的静态库仑应力变化解释地震的空间迁移和余震的空间分布规律,但是,在计算静态库仑应力场时,室内试验数据和观测资料往往无法对计算所涉及的参数进行足够的约束,而参数取值的不确定性会直接影响到静态库仑应力的计算结果。不同研究组得到的汶川地震产生的静态库仑应力变化结果并不一样,为研究不同计算模型和参数的选取对静态库仑应力计算的影响,我们通过建立模型并依次改变参数,分析比较了各个参数对计算结果的影响。结果表明:重力、接收断层位置和走向等的影响较小,其他参数均会对静态库仑应力变化量值和符号造成不同程度的影响,其影响在地震破裂面周边尤其明显,计算时参数敏感性分析不可忽略。
Static Coulomb stress change induced by earthquake slip is used frequently to explain earthquake activities and aftershocks distribution.However,some parameters for the Coulomb stress calculation are unable to be well constrained from laboratory experiments and field observations.Different parameters may directly affect the pattern of static Coulomb stress.The static Coulomb stress changes induced by the Wenchuan earthquake calculated by 6 research groups are not consistent with each other.To investigate how the parameters affect the calculation results,we change the parameters in turn through modeling and compare the results of different calculation parameters.We find that gravity,receiver faults position and strike have little influence on coseismic Coulomb stress change calculation,but other parameters can change the value and sign of the results in various degrees especially around the earthquake rupture plane.Therefore,the uncertainty of the static Coulomb stress change induced by earthquake should be taken into consideration of the earthquake hazard analysis.
Static Coulomb stress change induced by earthquake slip is used frequently to explain earthquake activities and aftershocks distribution.However,some parameters for the Coulomb stress calculation are unable to be well constrained from laboratory experiments and field observations.Different parameters may directly affect the pattern of static Coulomb stress.The static Coulomb stress changes induced by the Wenchuan earthquake calculated by 6 research groups are not consistent with each other.To investigate how the parameters affect the calculation results,we change the parameters in turn through modeling and compare the results of different calculation parameters.We find that gravity,receiver faults position and strike have little influence on coseismic Coulomb stress change calculation,but other parameters can change the value and sign of the results in various degrees especially around the earthquake rupture plane.Therefore,the uncertainty of the static Coulomb stress change induced by earthquake should be taken into consideration of the earthquake hazard analysis.
引文
曹娟娟、刘百篪、闻学泽,2003,西秦岭北缘断裂带特征地震平均复发间隔的确定和地震危险性评价,26(4),372～381。
邓起东、张培震、冉勇康等,2002,中国活动构造基本特征,中国科学D辑:地球科学,32(12),1020～1030。
傅征祥、刘桂萍、陈棋福,2001,青藏高原北缘海原、古浪、昌马大地震间相互作用的动力学分析,地震地质,23(1),35～42。
何宏林、池田安隆、何玉林等,2008,新生的大凉山断裂带-鲜水河-小江断裂系中段的裁弯取直,中国科学D辑:地球科学,38(5),564～574。
黄伟、周荣军,2000,四川玉农希断裂的全新世活动与1975年康定六巴6.2级地震,中国地震,16(1),53～59。
李陈侠、徐锡伟、闻学泽等,2009,东昆仑断裂东段玛沁-玛曲段几何结构特征,地震地质,31(3),441～458。
潘懋、梁海华、蔡永恩等,1994,中国川西地区鲜水河断裂和则木河断裂几何学、运动学特征及震活动性对比研究,中国地震,10(1),28～37。
单斌、熊熊、郑勇等,2009,2008年5月12日MW7.9汶川地震导致的周边断层应力变化,中国科学D辑:地球科学,39(5),537～545。
石耀霖、曹建玲,2010,库仑应力计算及应用过程中若干问题的讨论——以汶川地震为例,地球物理学报,53(1),102～110。
王连捷、周春景、孙东生等,2008,汶川5.12地震引起的库仑应力变化及其对周边地震活动的影响,地质力学学报,14(3),193～120。
王卫民、赵连锋、李娟等,2008,四川汶川8.0级地震震源过程,地球物理学报,51(5),1403～1410。
王伟涛、贾东、李传友等,2008,四川龙泉山断裂带变形特征及其活动性初步研究,地震地质,30(4),969～977。
王阎昭、王恩宁、叶建青等,2008,基于GPS资料约束反演川滇地区主要断裂现今活动速率,中国科学D辑:地球科学,38(5),582～597。
万永革、吴忠良、周公威等,2002,地震静态应力触发模型的全球检验,地震学报,24(3),302～316。
万永革、沈正康、盛书中等,2009,2008年汶川大地震对周围断层的影响,地震学报,31(2),128～139。
闻学泽,1999,中国大陆活动断裂的段破裂地震复发行为,地震学报,21(4),411～418。
闻学泽、杜平山、龙德雄,2000,安宁河断裂带小相岭段古地震的新证据及最晚事件的年代,地震地质,22(1),1～8。
闻学泽、徐锡伟、郑荣章等,2003,甘孜-玉树断裂的平均滑动速率与近代大地震破裂,中国科学D辑:地球科学,33(增刊),200～208。
徐锡伟、张培震、闻学泽等,2005,川西及其邻近地区活动构造基本特征与强震复发模型,地震地质,27(3),447～461。
徐锡伟、闻学泽等、陈桂华等,2008,巴颜喀拉地块东部龙日坝断裂带的发现及其大地构造意义,中国科学D辑:地球科学,38(5),529～542。
张国宏、单新建、李卫东,2008,汶川Ms8.0地震库仑破裂应力变化及断层危险性初步研究,地震地质,30(4),935～943。
张培震、徐锡伟、闻学泽等,2008,2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因,地球物理学报,51(4),1066～1073。
张勇、冯万鹏、许力生等,2008,2008年汶川大地震的时空破裂过程,中国科学D辑:地球科学,38(10),1186～1194。
周荣军、何玉林、马声浩等,1999,四川小金抚边河断裂的晚第四纪活动特征,地震研究,22(4),377～381。
Allen C.R.,Luo Z.,Qian H.,et al.,1991,Field study of a highly active fault zone:The Xianshuihe fault of south-westChina,Geol.Soc.Am.Bull.,103(9),1178～1199.
Bassin C.,Laske G.,Masters G.,2000,The Current Limits of Resolution for Surface Wave Tomography in North America,EOS.Trans.AGU.,81,F897.
Burchfiel B.C.,Royden L.H.,van de Hilst R D.,et al.,2008,A geological and geophysical context for the Wenchuanearthquake of12May2008,Sichuan,People's Republic of China,GSA.Today,18(7),4～11.
Chen S.F.,Wilson C.J.L.,Deng Q.D.,et al.,1994,Active faulting and block movement associated with large earthquakein the Min Shan and Longmen Mountains,northeastern Tibetan Plateau,J.Geophys.Res.,99,24025～24038.
Cocco M.,Rice J.R.,2002,Pore pressure and poroelasticity effects in coulomb stress analysis of earthquake interactions,J.Geophys.Res.,108(B2),ESE.2.1～ESE.2.17.
Deng J.,Sykes L.R.,1997,Evolution of the stress field in southern California and triggering of moderate size earthquake:A200-year perspective,J.Geophys.Res.,102(B5),9859～9886.
Ji C.,Hayes G.,2008,Preliminary result of the May12,2008MW7.9eastern Sichuan,http://earthquake.usgs.gov/eqcenter/eqinthenews/2008/us2008ryan/finite_fault.php.
King G.C.P.,Stein R.S.,Lin J.,1994,Static stress change and the trigger of earthquake,Bull.Seismol.Soc.Am.,84(3),935～953.
Kirby E.,Whipple K.X.,Burchfiel B.C.,et al.,2000,Neotectonics of the Minshan,China:Implication for mechanismsdriving Quaternary deformation along the eastern margin of the Tibetan Plateau,Geol.Soc.Am.Bull.,112(3),375～393.
Lin J.,Stein R.S.,2004,Stress triggering in thrust and subduction earthquakes,and stress interaction between the southern SanAndreas and nearby thrust and strike slip faults,J.Geophys.Res.,109,B02303.
Okada Y.,1992,Internal deformation due to shear and tensile faults in a half space,Bull.Seismol.Soc.Am.,82,1018～1040.
Parsons T.,Ji C.,Kirby E.,2008,Stress changes from the2008Wenchuan earthquake and increased hazard in the Sichuanbasin,Nature,454,509～510.
Steacy S.,Marsan D.,Nalbant S.,et al.,2004,Sensitivity of static stress calculations to the earthquake slip distribution,J.Geophys.Res.,109,B04303.
Stein R.S.,Barka A.A.,Dieterich J.H.,1997,Progressive failure on the North Anatolian fault since1939by earthquakestress triggering,Geophys.J.Int.,128,594～604.
Toda S.J.,Lin J.,Meghraoui M.,et al.,2008,12May2008M=7.9Wenchuan,China,earthquake calculated to increasefailure stress and seismicity rate on three major fault systems,Geophys.Res.Lett.,35,L17305.
Wang R.J.,1999,A Simple Orthonormalization method for stable and efficient computation of green’s functions,Bull.Seism.Soc.Am.,89(3),733～741.
Wang R.J.,2005,The dislocation theory:a consistent way for including the gravity effect in(visco)elastic plane-earthmodels,Geophys.J.Int.,161,191～196.
邓起东、张培震、冉勇康等,2002,中国活动构造基本特征,中国科学D辑:地球科学,32(12),1020～1030。
傅征祥、刘桂萍、陈棋福,2001,青藏高原北缘海原、古浪、昌马大地震间相互作用的动力学分析,地震地质,23(1),35～42。
何宏林、池田安隆、何玉林等,2008,新生的大凉山断裂带-鲜水河-小江断裂系中段的裁弯取直,中国科学D辑:地球科学,38(5),564～574。
黄伟、周荣军,2000,四川玉农希断裂的全新世活动与1975年康定六巴6.2级地震,中国地震,16(1),53～59。
李陈侠、徐锡伟、闻学泽等,2009,东昆仑断裂东段玛沁-玛曲段几何结构特征,地震地质,31(3),441～458。
潘懋、梁海华、蔡永恩等,1994,中国川西地区鲜水河断裂和则木河断裂几何学、运动学特征及震活动性对比研究,中国地震,10(1),28～37。
单斌、熊熊、郑勇等,2009,2008年5月12日MW7.9汶川地震导致的周边断层应力变化,中国科学D辑:地球科学,39(5),537～545。
石耀霖、曹建玲,2010,库仑应力计算及应用过程中若干问题的讨论——以汶川地震为例,地球物理学报,53(1),102～110。
王连捷、周春景、孙东生等,2008,汶川5.12地震引起的库仑应力变化及其对周边地震活动的影响,地质力学学报,14(3),193～120。
王卫民、赵连锋、李娟等,2008,四川汶川8.0级地震震源过程,地球物理学报,51(5),1403～1410。
王伟涛、贾东、李传友等,2008,四川龙泉山断裂带变形特征及其活动性初步研究,地震地质,30(4),969～977。
王阎昭、王恩宁、叶建青等,2008,基于GPS资料约束反演川滇地区主要断裂现今活动速率,中国科学D辑:地球科学,38(5),582～597。
万永革、吴忠良、周公威等,2002,地震静态应力触发模型的全球检验,地震学报,24(3),302～316。
万永革、沈正康、盛书中等,2009,2008年汶川大地震对周围断层的影响,地震学报,31(2),128～139。
闻学泽,1999,中国大陆活动断裂的段破裂地震复发行为,地震学报,21(4),411～418。
闻学泽、杜平山、龙德雄,2000,安宁河断裂带小相岭段古地震的新证据及最晚事件的年代,地震地质,22(1),1～8。
闻学泽、徐锡伟、郑荣章等,2003,甘孜-玉树断裂的平均滑动速率与近代大地震破裂,中国科学D辑:地球科学,33(增刊),200～208。
徐锡伟、张培震、闻学泽等,2005,川西及其邻近地区活动构造基本特征与强震复发模型,地震地质,27(3),447～461。
徐锡伟、闻学泽等、陈桂华等,2008,巴颜喀拉地块东部龙日坝断裂带的发现及其大地构造意义,中国科学D辑:地球科学,38(5),529～542。
张国宏、单新建、李卫东,2008,汶川Ms8.0地震库仑破裂应力变化及断层危险性初步研究,地震地质,30(4),935～943。
张培震、徐锡伟、闻学泽等,2008,2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因,地球物理学报,51(4),1066～1073。
张勇、冯万鹏、许力生等,2008,2008年汶川大地震的时空破裂过程,中国科学D辑:地球科学,38(10),1186～1194。
周荣军、何玉林、马声浩等,1999,四川小金抚边河断裂的晚第四纪活动特征,地震研究,22(4),377～381。
Allen C.R.,Luo Z.,Qian H.,et al.,1991,Field study of a highly active fault zone:The Xianshuihe fault of south-westChina,Geol.Soc.Am.Bull.,103(9),1178～1199.
Bassin C.,Laske G.,Masters G.,2000,The Current Limits of Resolution for Surface Wave Tomography in North America,EOS.Trans.AGU.,81,F897.
Burchfiel B.C.,Royden L.H.,van de Hilst R D.,et al.,2008,A geological and geophysical context for the Wenchuanearthquake of12May2008,Sichuan,People's Republic of China,GSA.Today,18(7),4～11.
Chen S.F.,Wilson C.J.L.,Deng Q.D.,et al.,1994,Active faulting and block movement associated with large earthquakein the Min Shan and Longmen Mountains,northeastern Tibetan Plateau,J.Geophys.Res.,99,24025～24038.
Cocco M.,Rice J.R.,2002,Pore pressure and poroelasticity effects in coulomb stress analysis of earthquake interactions,J.Geophys.Res.,108(B2),ESE.2.1～ESE.2.17.
Deng J.,Sykes L.R.,1997,Evolution of the stress field in southern California and triggering of moderate size earthquake:A200-year perspective,J.Geophys.Res.,102(B5),9859～9886.
Ji C.,Hayes G.,2008,Preliminary result of the May12,2008MW7.9eastern Sichuan,http://earthquake.usgs.gov/eqcenter/eqinthenews/2008/us2008ryan/finite_fault.php.
King G.C.P.,Stein R.S.,Lin J.,1994,Static stress change and the trigger of earthquake,Bull.Seismol.Soc.Am.,84(3),935～953.
Kirby E.,Whipple K.X.,Burchfiel B.C.,et al.,2000,Neotectonics of the Minshan,China:Implication for mechanismsdriving Quaternary deformation along the eastern margin of the Tibetan Plateau,Geol.Soc.Am.Bull.,112(3),375～393.
Lin J.,Stein R.S.,2004,Stress triggering in thrust and subduction earthquakes,and stress interaction between the southern SanAndreas and nearby thrust and strike slip faults,J.Geophys.Res.,109,B02303.
Okada Y.,1992,Internal deformation due to shear and tensile faults in a half space,Bull.Seismol.Soc.Am.,82,1018～1040.
Parsons T.,Ji C.,Kirby E.,2008,Stress changes from the2008Wenchuan earthquake and increased hazard in the Sichuanbasin,Nature,454,509～510.
Steacy S.,Marsan D.,Nalbant S.,et al.,2004,Sensitivity of static stress calculations to the earthquake slip distribution,J.Geophys.Res.,109,B04303.
Stein R.S.,Barka A.A.,Dieterich J.H.,1997,Progressive failure on the North Anatolian fault since1939by earthquakestress triggering,Geophys.J.Int.,128,594～604.
Toda S.J.,Lin J.,Meghraoui M.,et al.,2008,12May2008M=7.9Wenchuan,China,earthquake calculated to increasefailure stress and seismicity rate on three major fault systems,Geophys.Res.Lett.,35,L17305.
Wang R.J.,1999,A Simple Orthonormalization method for stable and efficient computation of green’s functions,Bull.Seism.Soc.Am.,89(3),733～741.
Wang R.J.,2005,The dislocation theory:a consistent way for including the gravity effect in(visco)elastic plane-earthmodels,Geophys.J.Int.,161,191～196.