利用GPS观测的时间序列资料反演地壳地幔黏性结构
|
摘要
地球介质的黏度是地球动力学研究中的重要参数.在考虑震后震源区介质物性变化的情况下,本文提出利用GPS观测的时间序列资料反演地壳、地幔黏度的方法.计算中,将遗传算法与Marquardt法相结合,利用遗传算法搜索结果作为Marquardt法反演的初始模型,运用微扰法形成Jacobian矩阵.根据余震分布及地震波速度变化确定震源区的范围及介质的物性变化情况,利用黏弹性有限单元模型(Maxwell体)及台湾集集地震后GPS观测的时间序列数据,反演了台湾地区地壳、地幔的黏性系数.反演计算及数值实验表明,该方法反演黏度的效率高,稳定性好.反演结果初步显示台湾地区的地壳、地幔的黏度分别为1.2×1018Pa.s和3.6×1019Pa.s.
The viscous properties of Earth media are very important in geodynamics.Taking the physical property variation of focal media after earthquake into account,we propose a method to invert for the viscosities in lower crust and upper mantle from GPS temporal series measurements.Combining the genetic algorithm(GA) and Marquardt inversion,we regard the optimum model found by GA as the initial model to carry out inversion by Marquardt method,in which the Jacobian matrix is produced by small perturbation.The focal region and physical properties are decided by aftershocks and velocity changes of seismic wave.We apply viscoelastic finite element method to determine the viscosities in Taiwan with GPS measurements after Chi-Chi,Taiwan,earthquake.Inversion computation and digital experiments show that the inversion method is highly efficient and stable.The preliminary result suggests that the viscosities of lower crust and upper mantle in Taiwan are 1.2×10~(18)Pa·s and 3.6×10~(19)Pa·s,respectively.
The viscous properties of Earth media are very important in geodynamics.Taking the physical property variation of focal media after earthquake into account,we propose a method to invert for the viscosities in lower crust and upper mantle from GPS temporal series measurements.Combining the genetic algorithm(GA) and Marquardt inversion,we regard the optimum model found by GA as the initial model to carry out inversion by Marquardt method,in which the Jacobian matrix is produced by small perturbation.The focal region and physical properties are decided by aftershocks and velocity changes of seismic wave.We apply viscoelastic finite element method to determine the viscosities in Taiwan with GPS measurements after Chi-Chi,Taiwan,earthquake.Inversion computation and digital experiments show that the inversion method is highly efficient and stable.The preliminary result suggests that the viscosities of lower crust and upper mantle in Taiwan are 1.2×10~(18)Pa·s and 3.6×10~(19)Pa·s,respectively.
引文
[1]Deng J,Michael Gurnis,Hiroo Kanamori,et al.Viscoelastic flow inthe lower crust after the 1992 Landers,California,earthquake.Science,1998,282:1689~1692
[2]Flesch L M,William E Holt,John Haines,et al.Dynamics of thePacific_North American plate boundary in the Western United States.Science,2000,287:834~836
[3]Hearn E H.What can GPS data tell us about the dynamics of post_seismic deformation?Geophys.J.Int.,2003,155:753~777
[4]Hu Y,Wang K,He J,et al.Three_dimensional viscoelastic finiteelement model for postseismic deformation of the great 1960 Chileearthquake.J.Geophys.Res.,2004,109,B12 403,doi:10.1029/2004JB003163
[5]Pollitz F F,Peltzer G,rgmann R B.Mobility of continental mantle:Evidence from postseismic geodetic observations following the 1992Landers earthquake.J.Geophys.Res.,2000,105:8038~8054
[6]Pollitz F F,rgmann R B,Segall P.Joint estimation of afterslip rateand postseismic relaxation following the 1989 Loma Prietaearthquake.J.Geophys.Res.,1998,103:26975~26992
[7]Hearn E H,rgmann R B,Reilinger R E.Dynamics of Izmitearthquake postseismic deformation and loading of the Düzeeearthquake hypocenter.Bull.Seism.Soc.Am.,2002,92:172~193
[8]Ueda H,Ohtake M,Sato H.Postseismic crustal deformationfollowing the 1993 Hokkaido Nanseioki earthquake,northern Japan:Evidence for a low_viscosity zone in the uppermost mantle.J.Geophys.Res.2003,108(B3):doi:10.1029/2002JB002067
[9]Thanassoulas C,Tselentis G A,Dimitriadis K.Gravity inversion of afault by Marquardt s method.Computers&Geosciences,1987,13(4):399~404
[10]Marquardt D W.An algorithm for least squares estimation of nonlinearparameters.Journal of the Society for Industrial Applications ofMathematics,1963,11(2):431~441
[11]朱守彪,石耀霖.用遗传有限单元法反演川滇下地壳流动对上地壳的拖曳作用.地球物理学报.2004,47(2):232~239Zhu S B,Shi Y L.Genetic algorithm_finite element inversion of dragforces exerted by the lower curst on the upper crust in the Sichuan_Yunnan area.Chinese J.Geophys.(in Chinese),2004,47(2):232~239
[12]Yu S B,Hsu Y J,Kuo L C,et al.GPS measurement of postseismicdeformation following the 1999 Chi_Chi,Taiwan,earthquake.J.Geophys.Res.,2003,108,doi:10.1029/2003JB002396
[13]Johnson K M,Segall P.Imaging the ramp_d?collement geometry ofthe Chelungpu fault using coseismic GPS displacements from the 1999Chi_Chi,Taiwan earthquake.Tectonophysics,2004,378:123~139
[14]Yen Horng_Yuan,Yeh Yih_Hsiung,Wu Francis T.Two_dimensionalcrustal structures of Taiwan from gravity data.Tectonics,1998,17(1):104~111
[15]Lin A T,Watts A B.Origin of the West Taiwan basin by orogenicloading and flexure of a rifted continental margin.J.Geophys.Res.,2002,107(B9),2185,doi:10.1029/2001JB000669
[16]Dziewonski A M,Anderson D L.Preliminary reference Earth model.Phys.Earth Planet.Inter.,1981,25:297~356
[17]王彦斌,王永,李建成等.1999年台湾集集大震的地表断层破裂特征.地震地质,2000,22(2):97~103Wang Y B,Wang Y,Li J C,et al.Characteristics of groundruptures caused by the 1999M7.3 earthquake of Jiji,Taiwan.Seismology and Geology(in Chinese),2000,22(2):97~103
[18]Shieh C F,Sheu S Y,Shih R C.Correlation between surface damageand the coseismic displacement and stress relaxation of the 1999 Chi_Chi earthquake.Geophys.Res.Lett.,2001,28:3381~3384
[19]Chen C H,Wang W H,Teng T L.3D velocity structure around thesource area of the 1999 Chi_Chi,Taiwan,earthquake:before andafter the mainshock.Bull.Seism.Soc.Am.,2001,91(5):1013~1027
[20]Chen K C,Huang B S,Wang J H,et al.Conjugate thrust faultingassociated with the 1999 Chi_Chi,Taiwan,earthquake sequence.Geophys.Res.Lett.,2002,29(8):1277,10.1029/2001GL014250
[21]Lee J C,Chu H T,Angelier J,et al.Geometry and structure ofnorthern surface ruptures of the 1999Mw=7.6 Chi_Chi Taiwanearthquake:influence from inherited fold belt from inherited fold beltstructures.Journal of Structural Geology,2002,24:173~192
[22]郭振伏,武晓松,余陵等.底排火箭复合增程弹助火箭推进剂结构完整性分析.弹道学报,2003,15(2):34~38Guo Z F,Wu X S,Yu L,et al.Structural integrality analysis ofrocket grain of base bleed_rocket compound extended range projectile.Journal of Balistics(in Chinese),2003,15(2):34~38
[23]周光泉,刘孝敏.粘弹性理论.合肥:中国科学技术大学出版社,1996Zhou G Q,Liu X M.Theory of Viscoelasticity(in Chinese).Hefei:China University of Science and Technology China Press,1996
[24]Yu S B,Chen H Y,Kuo L C.Velocity field of GPS stations in theTaiwan area.Tectonophysics,1997,274:41~59
[25]Dondurur D,Coskun Sar.A Fortran 77 computer code for dampedleast_squares inversion of Slingram electromagnetic anomalies overthin tabular conductors.Computers&Geosciences,2004,30:591~599
[26]Kao H,Chen W P.The Chi_Chi earthquake sequence:Active,out_of_sequence thrust faulting in Taiwan.Science,2000,288:2346~2349
[27]Lin C H.Thermal modeling of continental subduction and exhumationconstrained by heat flow and seismicity in Taiwan.Tectonophysics,2000,324:189~201
[28]Shen Z,Jackson D D,Feng Y,et al.Postseismic deformationfollowing the Landers earthquake,California,28 June 1992.Bull.Seism.Soc.Am.,1994,84(3):780~791
[29]Savage J C,Svarc J L.Postseismic deformation associated with the1992Mw=7.3 Landers earthquake,southern California.J.Geophys.Res.,1997,102:7565~7577
[2]Flesch L M,William E Holt,John Haines,et al.Dynamics of thePacific_North American plate boundary in the Western United States.Science,2000,287:834~836
[3]Hearn E H.What can GPS data tell us about the dynamics of post_seismic deformation?Geophys.J.Int.,2003,155:753~777
[4]Hu Y,Wang K,He J,et al.Three_dimensional viscoelastic finiteelement model for postseismic deformation of the great 1960 Chileearthquake.J.Geophys.Res.,2004,109,B12 403,doi:10.1029/2004JB003163
[5]Pollitz F F,Peltzer G,rgmann R B.Mobility of continental mantle:Evidence from postseismic geodetic observations following the 1992Landers earthquake.J.Geophys.Res.,2000,105:8038~8054
[6]Pollitz F F,rgmann R B,Segall P.Joint estimation of afterslip rateand postseismic relaxation following the 1989 Loma Prietaearthquake.J.Geophys.Res.,1998,103:26975~26992
[7]Hearn E H,rgmann R B,Reilinger R E.Dynamics of Izmitearthquake postseismic deformation and loading of the Düzeeearthquake hypocenter.Bull.Seism.Soc.Am.,2002,92:172~193
[8]Ueda H,Ohtake M,Sato H.Postseismic crustal deformationfollowing the 1993 Hokkaido Nanseioki earthquake,northern Japan:Evidence for a low_viscosity zone in the uppermost mantle.J.Geophys.Res.2003,108(B3):doi:10.1029/2002JB002067
[9]Thanassoulas C,Tselentis G A,Dimitriadis K.Gravity inversion of afault by Marquardt s method.Computers&Geosciences,1987,13(4):399~404
[10]Marquardt D W.An algorithm for least squares estimation of nonlinearparameters.Journal of the Society for Industrial Applications ofMathematics,1963,11(2):431~441
[11]朱守彪,石耀霖.用遗传有限单元法反演川滇下地壳流动对上地壳的拖曳作用.地球物理学报.2004,47(2):232~239Zhu S B,Shi Y L.Genetic algorithm_finite element inversion of dragforces exerted by the lower curst on the upper crust in the Sichuan_Yunnan area.Chinese J.Geophys.(in Chinese),2004,47(2):232~239
[12]Yu S B,Hsu Y J,Kuo L C,et al.GPS measurement of postseismicdeformation following the 1999 Chi_Chi,Taiwan,earthquake.J.Geophys.Res.,2003,108,doi:10.1029/2003JB002396
[13]Johnson K M,Segall P.Imaging the ramp_d?collement geometry ofthe Chelungpu fault using coseismic GPS displacements from the 1999Chi_Chi,Taiwan earthquake.Tectonophysics,2004,378:123~139
[14]Yen Horng_Yuan,Yeh Yih_Hsiung,Wu Francis T.Two_dimensionalcrustal structures of Taiwan from gravity data.Tectonics,1998,17(1):104~111
[15]Lin A T,Watts A B.Origin of the West Taiwan basin by orogenicloading and flexure of a rifted continental margin.J.Geophys.Res.,2002,107(B9),2185,doi:10.1029/2001JB000669
[16]Dziewonski A M,Anderson D L.Preliminary reference Earth model.Phys.Earth Planet.Inter.,1981,25:297~356
[17]王彦斌,王永,李建成等.1999年台湾集集大震的地表断层破裂特征.地震地质,2000,22(2):97~103Wang Y B,Wang Y,Li J C,et al.Characteristics of groundruptures caused by the 1999M7.3 earthquake of Jiji,Taiwan.Seismology and Geology(in Chinese),2000,22(2):97~103
[18]Shieh C F,Sheu S Y,Shih R C.Correlation between surface damageand the coseismic displacement and stress relaxation of the 1999 Chi_Chi earthquake.Geophys.Res.Lett.,2001,28:3381~3384
[19]Chen C H,Wang W H,Teng T L.3D velocity structure around thesource area of the 1999 Chi_Chi,Taiwan,earthquake:before andafter the mainshock.Bull.Seism.Soc.Am.,2001,91(5):1013~1027
[20]Chen K C,Huang B S,Wang J H,et al.Conjugate thrust faultingassociated with the 1999 Chi_Chi,Taiwan,earthquake sequence.Geophys.Res.Lett.,2002,29(8):1277,10.1029/2001GL014250
[21]Lee J C,Chu H T,Angelier J,et al.Geometry and structure ofnorthern surface ruptures of the 1999Mw=7.6 Chi_Chi Taiwanearthquake:influence from inherited fold belt from inherited fold beltstructures.Journal of Structural Geology,2002,24:173~192
[22]郭振伏,武晓松,余陵等.底排火箭复合增程弹助火箭推进剂结构完整性分析.弹道学报,2003,15(2):34~38Guo Z F,Wu X S,Yu L,et al.Structural integrality analysis ofrocket grain of base bleed_rocket compound extended range projectile.Journal of Balistics(in Chinese),2003,15(2):34~38
[23]周光泉,刘孝敏.粘弹性理论.合肥:中国科学技术大学出版社,1996Zhou G Q,Liu X M.Theory of Viscoelasticity(in Chinese).Hefei:China University of Science and Technology China Press,1996
[24]Yu S B,Chen H Y,Kuo L C.Velocity field of GPS stations in theTaiwan area.Tectonophysics,1997,274:41~59
[25]Dondurur D,Coskun Sar.A Fortran 77 computer code for dampedleast_squares inversion of Slingram electromagnetic anomalies overthin tabular conductors.Computers&Geosciences,2004,30:591~599
[26]Kao H,Chen W P.The Chi_Chi earthquake sequence:Active,out_of_sequence thrust faulting in Taiwan.Science,2000,288:2346~2349
[27]Lin C H.Thermal modeling of continental subduction and exhumationconstrained by heat flow and seismicity in Taiwan.Tectonophysics,2000,324:189~201
[28]Shen Z,Jackson D D,Feng Y,et al.Postseismic deformationfollowing the Landers earthquake,California,28 June 1992.Bull.Seism.Soc.Am.,1994,84(3):780~791
[29]Savage J C,Svarc J L.Postseismic deformation associated with the1992Mw=7.3 Landers earthquake,southern California.J.Geophys.Res.,1997,102:7565~7577
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