孔隙介质地震电磁信号的数值模拟研究
|
摘要
本文利用最近开发的孔隙介质震电波场算法开展了数值模拟研究,重点探讨不同结构模型中双力偶点源以及有限断层面源作用下产生的地震波及其伴随的电磁信号的时域和频域特征,考察了不同震源时间函数类型对震电波场数值模拟结果的影响,并以Ricker子波为例讨论了震电波场的频率响应特征.结果表明:地震电磁信号的波形、振幅和持续时间等都不同程度受到模型结构的影响,结构越复杂,波形也越复杂;不同震源(双力偶点源与有限断层面源、震源时间函数类型、Ricker子波峰值频率)产生的位移场和电磁场在波形和频谱响应方面整体上呈现相似的特征,但在波形和频谱的幅度和复杂程度方面存在一定差异.
Based on the recently developed numerical method,we simulated the co-seismic electromagnetic(EM) signals in porous media.We focused on the characteristics of the co-seismic EM signals generated by a double couple point source or a finite fault planar source in the models with different structures.The effects of source time function type and peak frequency also have been investigated.The simulation results show that the waveform,amplitude and duration time of seismic-EM signals depend somehow on the model structures;the seismic waves and EM signals for different source models(a double couple point source or a finite fault planar source,source time functions,peak frequencies) also show similar characteristics in both time and frequency domains,although there are some differences for the amplitude and complexity of waveform and frequency response.
Based on the recently developed numerical method,we simulated the co-seismic electromagnetic(EM) signals in porous media.We focused on the characteristics of the co-seismic EM signals generated by a double couple point source or a finite fault planar source in the models with different structures.The effects of source time function type and peak frequency also have been investigated.The simulation results show that the waveform,amplitude and duration time of seismic-EM signals depend somehow on the model structures;the seismic waves and EM signals for different source models(a double couple point source or a finite fault planar source,source time functions,peak frequencies) also show similar characteristics in both time and frequency domains,although there are some differences for the amplitude and complexity of waveform and frequency response.
引文
[1]Matsushima M,Honkura Y,Oshiman N,et al.Seismoelectromagnetic effect associated with the I.zmitearthquake and its aftershocks.Bull.Seism.Soc.Am.,2002,92:350-360.
[2]Karakelian D,Beroza G C,Klemperer S L,et al.Analysis ofultralow-frequency electromagnetic field measurements associatedwith the 1999 M7.1 Hector Mine,California,earthquakesequence.Bull.Seism.Soc.Am.,2002,92:1513-1524.
[3]汤吉,詹艳,王立凤等.5月12日汶川8.0级地震强余震观测的电磁同震效应.地震地质,2008,30(3):739-745.Tang J,Zhan Y,Wang L F,et al.Coseismic signal associatedwith aftershock of the Ms8.0Wenchuan earthquake.Seismologyand Geology(in Chinese),2008,30(3):739-745.
[4]汤吉,詹艳,王立凤等.汶川地震强余震的电磁同震效应.地球物理学报,2010,53(3):526-534.Tang J,Zhan Y,Wang L F,et al.Electromagnetic coseismiceffect associated with aftershock of Wenchuan Ms8.0earthquake.Chinese J.Geophys.(in Chinese),2010,53(3):526-534.
[5]Ivanov A G.Effect of electrization of earth layers by elasticwaves passing through them.Dokl.Akad.Nauk.SSSR,1939,24:42-45.
[6]Frenkel J.On the theory of seismic and seismoelectricphenomena in a moist soil.J.Eng.Mech.,1944,8(4):230-241.
[7]Pride S R.Governing equations for the coupled electromagneticsand acoustics of porous media.Phys.Rev.B,1994,50:15678-15696.
[8]Haartsen M W,Pride S R.Electroseismic waves from pointsources in layered media.J.Geophys.Res.,1997,102:24745-24769.
[9]Garambois S,Dietrich M.Full waveform numericalsimulations of seismoelectromagnetic wave conversions influid-saturated stratified porous media.J.Geophys.Res.,2002,107:40-58.
[10]Chen X F.Seismogram synthesis in multi-layered half-spacepart I.Theoretical formulations.Earthquake Research inChina,1999,13:149-174.
[11]Ge Z X,Chen X F.Wave propagation in irregularly layeredelastic models:A boundary element approach with a globalreflection/transmission matrix propagator.Bull.Seism.Soc.Am.,2007,97(3):1025-1031.
[12]Ren H X,Huang Q H,Chen X F.A new numerical techniquefor simulating the coupled seismic and electromagnetic waves inlayered porous media.Earthq.Sci.,2010,23:167-176.
[13]Ren H,Huang Q H,Chen X.Analytical regularization ofthe high-frequency instability problem in numerical simulationof seismoelectric wave-fields in multi-layered porous media.Chinese J.Geophys.,2010(b),53:506-511.
[14]Martner S T,Sparks N R.The electroseismic effect.Geophys.,1959,24:297-308.
[15]Thompson A H,Gist G A.Geophysical applications ofelectrokinetic conversion.Leading Edge,1993,12:1169-1173.
[16]Thompson A H,Hornbostel S,Burns J,et al.Field tests ofelectroseismic hydrocarbon detection.Geophys.,2007,72:N1-N9.
[17]Zhu Z,Cheng C H,Toksz M N.Electro-kinetic conversionin a fluid-saturated porous rock sample.SEG TechnicalProgram Expanded Abstracts,1994,1057-1060.
[18]Zhu Z,Haartsen M W,Toksz M N.Experimental studiesof electrokinetic conversions in fluid-saturated boreholemodels.Geophys.,1999,64:1349-1356.
[19]Zhu Z,Haartsen M W,Toksz M N.Experimental studiesof seismoelectric conversions in fluid-saturated porous media.J.Geophys.Res.,2000,105:28055-28064.
[20]Huang Q H.Rethinking earthquake-related DC-ULFelectromagnetic phenomena:towards a physics-based approach.Nat.Haiards Earth Syse.Sci.,2011,11(11):2941-2949.
[21]Gao Y H,Hu H S.Seismoelectromagnetic waves radiated bya double couple source in a saturated medium.Geophys.J.Int.,2010,181:873-896.
[22]Hu H S,Gao Y X.Electromagnetic field generated by afinite fault due to electrokinetic effect.J.Geophys.Res.,2011,116.
[23]Ren H X,Chen X F,Huang Q H.Numerical simulation ofcoseismic electromagnetic fields associated with seismic wavesdue to finite faulting in porous media.Geophys.J.Int.,2012,188:925-944.
[24]Gao Y X,Chen X F,Hu H S,et al.Early electromagneticwaves from earthquake rupturing:I.theoreticalformulations.Geophys.J.Int.,2013,192:1288-1307.
[25]Gao Y X,Chen X F,Hu H S,et al.Early electromagneticwaves from earthquake rupturing:II.validation and numericalexperiments.Geophys.J.Int.,2013,192:1308-1323.
[26]Bouchon M.A simple method to calculate Green′s functionsfor elastic layered media.Bull.Seism.Soc.Am.,1981,71:959-971.
[27]Herrmann R B.SH-wave generation by dislocation source—anumerical study.Bull.Seism.Soc.Am.,1979,69:1-15.
[2]Karakelian D,Beroza G C,Klemperer S L,et al.Analysis ofultralow-frequency electromagnetic field measurements associatedwith the 1999 M7.1 Hector Mine,California,earthquakesequence.Bull.Seism.Soc.Am.,2002,92:1513-1524.
[3]汤吉,詹艳,王立凤等.5月12日汶川8.0级地震强余震观测的电磁同震效应.地震地质,2008,30(3):739-745.Tang J,Zhan Y,Wang L F,et al.Coseismic signal associatedwith aftershock of the Ms8.0Wenchuan earthquake.Seismologyand Geology(in Chinese),2008,30(3):739-745.
[4]汤吉,詹艳,王立凤等.汶川地震强余震的电磁同震效应.地球物理学报,2010,53(3):526-534.Tang J,Zhan Y,Wang L F,et al.Electromagnetic coseismiceffect associated with aftershock of Wenchuan Ms8.0earthquake.Chinese J.Geophys.(in Chinese),2010,53(3):526-534.
[5]Ivanov A G.Effect of electrization of earth layers by elasticwaves passing through them.Dokl.Akad.Nauk.SSSR,1939,24:42-45.
[6]Frenkel J.On the theory of seismic and seismoelectricphenomena in a moist soil.J.Eng.Mech.,1944,8(4):230-241.
[7]Pride S R.Governing equations for the coupled electromagneticsand acoustics of porous media.Phys.Rev.B,1994,50:15678-15696.
[8]Haartsen M W,Pride S R.Electroseismic waves from pointsources in layered media.J.Geophys.Res.,1997,102:24745-24769.
[9]Garambois S,Dietrich M.Full waveform numericalsimulations of seismoelectromagnetic wave conversions influid-saturated stratified porous media.J.Geophys.Res.,2002,107:40-58.
[10]Chen X F.Seismogram synthesis in multi-layered half-spacepart I.Theoretical formulations.Earthquake Research inChina,1999,13:149-174.
[11]Ge Z X,Chen X F.Wave propagation in irregularly layeredelastic models:A boundary element approach with a globalreflection/transmission matrix propagator.Bull.Seism.Soc.Am.,2007,97(3):1025-1031.
[12]Ren H X,Huang Q H,Chen X F.A new numerical techniquefor simulating the coupled seismic and electromagnetic waves inlayered porous media.Earthq.Sci.,2010,23:167-176.
[13]Ren H,Huang Q H,Chen X.Analytical regularization ofthe high-frequency instability problem in numerical simulationof seismoelectric wave-fields in multi-layered porous media.Chinese J.Geophys.,2010(b),53:506-511.
[14]Martner S T,Sparks N R.The electroseismic effect.Geophys.,1959,24:297-308.
[15]Thompson A H,Gist G A.Geophysical applications ofelectrokinetic conversion.Leading Edge,1993,12:1169-1173.
[16]Thompson A H,Hornbostel S,Burns J,et al.Field tests ofelectroseismic hydrocarbon detection.Geophys.,2007,72:N1-N9.
[17]Zhu Z,Cheng C H,Toksz M N.Electro-kinetic conversionin a fluid-saturated porous rock sample.SEG TechnicalProgram Expanded Abstracts,1994,1057-1060.
[18]Zhu Z,Haartsen M W,Toksz M N.Experimental studiesof electrokinetic conversions in fluid-saturated boreholemodels.Geophys.,1999,64:1349-1356.
[19]Zhu Z,Haartsen M W,Toksz M N.Experimental studiesof seismoelectric conversions in fluid-saturated porous media.J.Geophys.Res.,2000,105:28055-28064.
[20]Huang Q H.Rethinking earthquake-related DC-ULFelectromagnetic phenomena:towards a physics-based approach.Nat.Haiards Earth Syse.Sci.,2011,11(11):2941-2949.
[21]Gao Y H,Hu H S.Seismoelectromagnetic waves radiated bya double couple source in a saturated medium.Geophys.J.Int.,2010,181:873-896.
[22]Hu H S,Gao Y X.Electromagnetic field generated by afinite fault due to electrokinetic effect.J.Geophys.Res.,2011,116.
[23]Ren H X,Chen X F,Huang Q H.Numerical simulation ofcoseismic electromagnetic fields associated with seismic wavesdue to finite faulting in porous media.Geophys.J.Int.,2012,188:925-944.
[24]Gao Y X,Chen X F,Hu H S,et al.Early electromagneticwaves from earthquake rupturing:I.theoreticalformulations.Geophys.J.Int.,2013,192:1288-1307.
[25]Gao Y X,Chen X F,Hu H S,et al.Early electromagneticwaves from earthquake rupturing:II.validation and numericalexperiments.Geophys.J.Int.,2013,192:1308-1323.
[26]Bouchon M.A simple method to calculate Green′s functionsfor elastic layered media.Bull.Seism.Soc.Am.,1981,71:959-971.
[27]Herrmann R B.SH-wave generation by dislocation source—anumerical study.Bull.Seism.Soc.Am.,1979,69:1-15.
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