川西及邻近地区地震活动性模拟和断层间相互作用研究
|
摘要
本研究采用基于库仑破裂准则的地震活动性准静态模型,模拟计算了川西地区长达10000年的理论地震目录,通过对理论地震目录的分析发现川西地区Ms≥7.0强震在时间上表现出很强的随机性,与平均地震发生率为1/22.0年-1(≈0.0454年-1)的Poisson过程很相近,Poisson模型可能是川西地区开展长期(数10年)地震危险性计算中较为合适的模型.而单一断层Ms≥7.0强震的时间间隔分布与Poisson过程存在很大的差异,用Poisson模型估计单一构造上长期地震危险性可能是不合适的.通过分析模拟产生的长时间理论地震目录,逐一给出了川西地区主要断层的Ms≥7.0强震的时间间隔分布与平均Ms≥7.0强震的复现时间,并讨论了主要断层间强震活动的相互关联,计算出了强震在各断层间的转移概率.定量计算了研究区一断层的破裂产生的库仑应力在研究区其他断层面上的投影.从而为研究断层间的相互作用,研究一断层发生强震对其他断层发生强震危险性的影响提供了依据.本文为开展区域地震危险性分析研究提出了新的思想和途径.
Seismicity over 10000 years in Western Sichuan of China has been simulated based on the mechanical synthetic seismicity model we developed. According to the analysis of the simulated synthetic seismic catalogue, the occurrence of strong earthquakes with Ms≥7.0 in the whole region of Western Sichuan is rather random, very close to the Poisson process with seismic rate 0.0454/year, which means it is reasonable to estimate the regional earthquake risk with Poisson model in Western Sichuan. However, the occurrence of strong earthquakes with Ms≥7.0 on the individual faults of Western Sichuan is far from Poisson process and could be predicted with a time-dependent prediction model. The fault interaction matrices and earthquake transfer possibility matrices among the faults in Western Sichuan have been calculated based on the analysis of the simulated synthetic catalogues. We have also calculated the static change in Coulomb failure stress (CFS)on one fault induced by a strong earthquake on another fault in Western Sichuan to discuss the physical implications of the earthquake transfer possibility matrices inferred from the synthetic catalogue.
Seismicity over 10000 years in Western Sichuan of China has been simulated based on the mechanical synthetic seismicity model we developed. According to the analysis of the simulated synthetic seismic catalogue, the occurrence of strong earthquakes with Ms≥7.0 in the whole region of Western Sichuan is rather random, very close to the Poisson process with seismic rate 0.0454/year, which means it is reasonable to estimate the regional earthquake risk with Poisson model in Western Sichuan. However, the occurrence of strong earthquakes with Ms≥7.0 on the individual faults of Western Sichuan is far from Poisson process and could be predicted with a time-dependent prediction model. The fault interaction matrices and earthquake transfer possibility matrices among the faults in Western Sichuan have been calculated based on the analysis of the simulated synthetic catalogues. We have also calculated the static change in Coulomb failure stress (CFS)on one fault induced by a strong earthquake on another fault in Western Sichuan to discuss the physical implications of the earthquake transfer possibility matrices inferred from the synthetic catalogue.
引文
[1]Ward S N.An application of synthetic seismicity in earthquake statistics:The middle America trench.J.Geophys.Res.,1992,92(B5):6675~6682
[2]Rundle J B,Klein W,Tiampo K,et al.Strategies for the detection and analysis of space-time patterns of earthquakes on complex fault systems.LECTNOTES COMPUTSC,2003,2659:827~836
[3]Robinson R,Benites R.Synthetic seismicity models for the Wellington Region,New Zealand:Implications for the temporal distribution.J.Geophys.Res.,1996,101(B12):27833~27844
[4]Kato N,Hirasawa T.Nonuniform and unsteady sliding of a plate boundaryin a great earthquake cycle:Anumerical simulation using a laboratory-derivedfrictionlaw.Pure Appl.Geophys.,1999,155:93~118
[5]Ben-Zion Y,Eneva M,Liu Y.Large earthquake cycles andintermittent criticality on heterogeneous faults due to evolving stress and seismicity.J.Geophys.Res.,2003,108(6):ESE4-1~4-21
[6]Robinson R,Benites R.Upgrading a synthetic seismicity model for more realistic fault ruptures.Geophys.Res.Letters,2001,28(9):1843~1846
[7]Dieterich J H.Modeling of rock friction1.experimental results and constitutive equations.J.Geophys.Res.,1979,84:2161~2168
[8]Zhou S,Johnston S,Robinson R,Vere-Jones D.Tests of the precursory accelerating moment release model using a synthetic seismicity model for Wellington,NewZealand.J.Geophys.Res.,2006,111,doi:10.1029/2005JB003720
[9]周仕勇,姜明明,Robinson R.1997年新疆伽师强震群发展过程中发震断层相互作用的影响.地球物理学报,2006,49(4):1102~1109Zhou S Y,Jiang MM,Robinson R.The role of fault interactions in the generation of the1997Jiashi strong earthquake swarm,Xinjiang,China.Chinese J.Geophys.(in Chinese),2006,49(4):1102~1109
[10]徐锡伟,张培震,闻学泽等.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,2005,27(3):447~461Xu X W,Zhang P Z,Wen XZ,et al.Fractures of active tectonics andrecurrence behaviors of strong earthquakesinthe western Sichuan province and its adjacent regions.Seismology and Geology(in Chinese),2005,27(3):447~461
[11]张培震,邓起东,张国民等.中国大陆的强震活动与活动地块.中国科学(D辑),2003,33(增刊):12~20Zhang P Z,Deng Q D,Zhang G M,et al.Active tectonic blocks and strong earthquakes inthe continental of China.Science in China(Ser.D),2003,46(Suppl):13~24
[12]唐荣昌,韩渭宾主编.四川活动断裂与地震.北京:地震出版社,1993,368Tang R C,Han W B.Active Faults and Earthquakes in Sichuan Province(in Chinese).Beijing:Seismological Press,1993
[13]申重阳,王琪,吴云等.川滇菱形块体主要边界运动模型的GPS数据反演分析.地球物理学报,2002,45(3):352~361Shen C Y,Wang Q,Wu Y,et al.GPSinversionof Kinematic model of the main boundaries of the rhombus blockin Sichuan and Yunan.Chinese J.Geophys.(in Chinese),2002,45(3):352~361
[14]Okada Y.Internal deformation duetoshear andtensilefaultsina half-space.Bull.Seis.Soc.Am.,1992,82:1018~1040
[15]Somerville P,Irikura K,Graves R,et al.Characterizing crustal earthquake slip models for the prediction of strong ground motion.Seismol.Res.Lett.,1999,70:59~80
[2]Rundle J B,Klein W,Tiampo K,et al.Strategies for the detection and analysis of space-time patterns of earthquakes on complex fault systems.LECTNOTES COMPUTSC,2003,2659:827~836
[3]Robinson R,Benites R.Synthetic seismicity models for the Wellington Region,New Zealand:Implications for the temporal distribution.J.Geophys.Res.,1996,101(B12):27833~27844
[4]Kato N,Hirasawa T.Nonuniform and unsteady sliding of a plate boundaryin a great earthquake cycle:Anumerical simulation using a laboratory-derivedfrictionlaw.Pure Appl.Geophys.,1999,155:93~118
[5]Ben-Zion Y,Eneva M,Liu Y.Large earthquake cycles andintermittent criticality on heterogeneous faults due to evolving stress and seismicity.J.Geophys.Res.,2003,108(6):ESE4-1~4-21
[6]Robinson R,Benites R.Upgrading a synthetic seismicity model for more realistic fault ruptures.Geophys.Res.Letters,2001,28(9):1843~1846
[7]Dieterich J H.Modeling of rock friction1.experimental results and constitutive equations.J.Geophys.Res.,1979,84:2161~2168
[8]Zhou S,Johnston S,Robinson R,Vere-Jones D.Tests of the precursory accelerating moment release model using a synthetic seismicity model for Wellington,NewZealand.J.Geophys.Res.,2006,111,doi:10.1029/2005JB003720
[9]周仕勇,姜明明,Robinson R.1997年新疆伽师强震群发展过程中发震断层相互作用的影响.地球物理学报,2006,49(4):1102~1109Zhou S Y,Jiang MM,Robinson R.The role of fault interactions in the generation of the1997Jiashi strong earthquake swarm,Xinjiang,China.Chinese J.Geophys.(in Chinese),2006,49(4):1102~1109
[10]徐锡伟,张培震,闻学泽等.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,2005,27(3):447~461Xu X W,Zhang P Z,Wen XZ,et al.Fractures of active tectonics andrecurrence behaviors of strong earthquakesinthe western Sichuan province and its adjacent regions.Seismology and Geology(in Chinese),2005,27(3):447~461
[11]张培震,邓起东,张国民等.中国大陆的强震活动与活动地块.中国科学(D辑),2003,33(增刊):12~20Zhang P Z,Deng Q D,Zhang G M,et al.Active tectonic blocks and strong earthquakes inthe continental of China.Science in China(Ser.D),2003,46(Suppl):13~24
[12]唐荣昌,韩渭宾主编.四川活动断裂与地震.北京:地震出版社,1993,368Tang R C,Han W B.Active Faults and Earthquakes in Sichuan Province(in Chinese).Beijing:Seismological Press,1993
[13]申重阳,王琪,吴云等.川滇菱形块体主要边界运动模型的GPS数据反演分析.地球物理学报,2002,45(3):352~361Shen C Y,Wang Q,Wu Y,et al.GPSinversionof Kinematic model of the main boundaries of the rhombus blockin Sichuan and Yunan.Chinese J.Geophys.(in Chinese),2002,45(3):352~361
[14]Okada Y.Internal deformation duetoshear andtensilefaultsina half-space.Bull.Seis.Soc.Am.,1992,82:1018~1040
[15]Somerville P,Irikura K,Graves R,et al.Characterizing crustal earthquake slip models for the prediction of strong ground motion.Seismol.Res.Lett.,1999,70:59~80
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