鲜水河断裂的几何形态对地震发生的影响
|
摘要
本文整理分析了鲜水河断裂的几何特征以及从1327年有记录以来6级以上历史地震的断层破裂位置和长度。选用速率和状态依赖性摩擦本构关系代表断裂区域物理性质,构建了鲜水河断裂3D物理模型模拟强震周期性。模拟结果与历史地震的发震有较好的一致性,主要表现在:1模拟结果在第二次地震周期之后,明显出现分段现象与鲜水河断裂分段的几何特征较为一致;2断裂北西端结构较为简单,地震发震情况也偏单一,在7级以上地震发震之前有6级以上地震的发生,此类现象与模拟结果一致;3断裂中段结构复杂,不仅存在分段还有轻度弯曲,模拟结果显示中段地震逐渐减小,破裂长度逐步缩短,并且出现级联破裂现象与历史地震较为吻合;43D模拟结果中,地震破裂区域起始与终止位置大都发生在断层转折的区域,特别是在乾宁和康定两处断层出现弯曲的位置,这与鲜水河断裂历史地震发震情况十分相似。
We analyze the geometrical feature along Xianshuihe fault as well as the locations of epicenters and the lengths of rupture zones generated by >M6 historical earthquakes since 1327. We choose the rate- and state-dependent friction law to represent the physical property of the fault zone to build a 3D model to simulate strong earthquake cycles. The simulation result has a good consistency with the historical earthquake data in four aspects: 1) After the second earthquake cycle, the earthquakes are allocated into 3 parts which is similar to the segmentation feature of the Xianshuihe fault. 2) The geometrical feature of northwest part of the fault is simple and the rupture of strong earthquakes is simple as well, which is in accordance with the simulation result. 3) The geometrical feature of northwest part of the fault is a little complicated and fault line is in curved shape. In the simulation result, earthquakes magnitude and the rupture zone are getting smaller in the middle part which is consistent with the historical data. 4) Rupture of some earthquakes terminates at the bending part of the fault line,especially at Qianning and Kangding where the fault bends, which shows how the shape of the fault line controls earthquake rupture.
We analyze the geometrical feature along Xianshuihe fault as well as the locations of epicenters and the lengths of rupture zones generated by >M6 historical earthquakes since 1327. We choose the rate- and state-dependent friction law to represent the physical property of the fault zone to build a 3D model to simulate strong earthquake cycles. The simulation result has a good consistency with the historical earthquake data in four aspects: 1) After the second earthquake cycle, the earthquakes are allocated into 3 parts which is similar to the segmentation feature of the Xianshuihe fault. 2) The geometrical feature of northwest part of the fault is simple and the rupture of strong earthquakes is simple as well, which is in accordance with the simulation result. 3) The geometrical feature of northwest part of the fault is a little complicated and fault line is in curved shape. In the simulation result, earthquakes magnitude and the rupture zone are getting smaller in the middle part which is consistent with the historical data. 4) Rupture of some earthquakes terminates at the bending part of the fault line,especially at Qianning and Kangding where the fault bends, which shows how the shape of the fault line controls earthquake rupture.
引文
邓启东,张培震,冉勇康,2002.中国活动构造基本特征.中国科学(D辑),32(12):1020—1029.
罗灼礼,钱洪,闻学泽,1987.鲜水河断裂与圣安德烈斯断层的地震地质对比研究.四川地震,(4):1-10.
M7专项工作组,2012.中国大陆大地震中-长期危险性研究.北京:地震出版社,31—35.
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、运动学特征及地震活动性对比研究.中国地震,10(1):28—37.
钱洪,1987.中美联合考察鲜水河断裂概述.国际地震动态,(10):9—10.
钱洪,C.R.艾伦,罗灼礼等,1988.全新世以来鲜水河断裂的活动特征.中国地震,4(2):9—18.
闻学泽,2000.四川西部鲜水河-安宁河-则木河断裂带的地震破裂分段特征.地震地质,22(3):239—249.
闻学泽,C.R.Allen,罗灼礼等,1989.鲜水河全新世断裂带的分段性几何特征及其地震构造意义.地震学报,11(4):362—372.
Dieterich J.H.,1981.Constitutive properties of rock with simulated gouge,in mechanical behavior of crustal rocks.Geophysical Monograph Series,24:108—120.
Dieterich J.H.,2009.Applications of rate-and state-dependent friction to models of fault slip and earthquake occurrence.Treatise on Geophysics,4(4):107—129.
Kato N.,Lei X.L.,Wen X.Z.,2007.A synthetic seismicity model for the Xianshuihe fault,southwestern China:simulation using a rate-and state-dependent friction law.Geophys.J.Int.,169:286—300.
Li Xiaofan,Bunichiro Shibazaki,2014.3D modeling of earthquake cycles of the Xianshuihe fault,southwestern China.Journal of Asian Earth Sciences,96(15):205—212.
Mair K.and Marone C.,1999.Friction of simulated fault gouge for a wide range of velocities and normal stresses.Journal of Geophysical Research,104:28899—28914.
Rice J.R.,1993.Spatio‐temporal complexity of slip on a fault.Journal of Geophysical Research,98:9885—9907.
Rice J.R.and Ruina A.L.,1980.Stability of steady frictional slipping.Journal of Applied Mechanics,50:343—349.
Rice J.R.and Tse S.T.,1986.Dynamic motion of a single degree of freedom system following a rate and state dependent friction law.J.Geophys.Res.,91:521—530.
Ruina A.,1983.Slip instability and state variable friction laws.Journal of Geophysical Research,88:10359—10370.
Scholz C.H.,2002.The mechanics of earthquakes and faulting.Cambridge University Press,244—299.
Scholz C.H.,1988.The critical slip distane for seismic faulting.Nature,336:761—763.
罗灼礼,钱洪,闻学泽,1987.鲜水河断裂与圣安德烈斯断层的地震地质对比研究.四川地震,(4):1-10.
M7专项工作组,2012.中国大陆大地震中-长期危险性研究.北京:地震出版社,31—35.
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、运动学特征及地震活动性对比研究.中国地震,10(1):28—37.
钱洪,1987.中美联合考察鲜水河断裂概述.国际地震动态,(10):9—10.
钱洪,C.R.艾伦,罗灼礼等,1988.全新世以来鲜水河断裂的活动特征.中国地震,4(2):9—18.
闻学泽,2000.四川西部鲜水河-安宁河-则木河断裂带的地震破裂分段特征.地震地质,22(3):239—249.
闻学泽,C.R.Allen,罗灼礼等,1989.鲜水河全新世断裂带的分段性几何特征及其地震构造意义.地震学报,11(4):362—372.
Dieterich J.H.,1981.Constitutive properties of rock with simulated gouge,in mechanical behavior of crustal rocks.Geophysical Monograph Series,24:108—120.
Dieterich J.H.,2009.Applications of rate-and state-dependent friction to models of fault slip and earthquake occurrence.Treatise on Geophysics,4(4):107—129.
Kato N.,Lei X.L.,Wen X.Z.,2007.A synthetic seismicity model for the Xianshuihe fault,southwestern China:simulation using a rate-and state-dependent friction law.Geophys.J.Int.,169:286—300.
Li Xiaofan,Bunichiro Shibazaki,2014.3D modeling of earthquake cycles of the Xianshuihe fault,southwestern China.Journal of Asian Earth Sciences,96(15):205—212.
Mair K.and Marone C.,1999.Friction of simulated fault gouge for a wide range of velocities and normal stresses.Journal of Geophysical Research,104:28899—28914.
Rice J.R.,1993.Spatio‐temporal complexity of slip on a fault.Journal of Geophysical Research,98:9885—9907.
Rice J.R.and Ruina A.L.,1980.Stability of steady frictional slipping.Journal of Applied Mechanics,50:343—349.
Rice J.R.and Tse S.T.,1986.Dynamic motion of a single degree of freedom system following a rate and state dependent friction law.J.Geophys.Res.,91:521—530.
Ruina A.,1983.Slip instability and state variable friction laws.Journal of Geophysical Research,88:10359—10370.
Scholz C.H.,2002.The mechanics of earthquakes and faulting.Cambridge University Press,244—299.
Scholz C.H.,1988.The critical slip distane for seismic faulting.Nature,336:761—763.
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