主动源在高频被动源面波测量中的应用
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摘要
被动源面波可弥补主动源面波测量中低频信息缺失的不足,因此引起人们的广泛研究。然而,被动源面波法不能提供高达几十赫兹的相速度信息,因此需要通过主动源面波法拓展频率范围。为了减少野外工作量,本文设计了一种高频被动源面波的勘探策略,即在连续的被动源面波测量过程中引入人工震源。我们称其为"混合源面波"(mixed-source surface-wave,MSW)测量。研究人员分别在学校内、马路边、铁路旁这三个噪声等级不同的地点记录短时长(10 min内)被动源面波和混合源面波。频谱分析表明,在连续的被动源面波观测中加入人工震源可以改善高频段能量。在记录的时间序列中分别应用了空间自相关(spatial autocorrelation,SPAC)法与基于互相关的被动源面波多道分析方法(multichannel analysis of passive surface,MAPS),结果表明该施工策略在高频段面波相速度分析中有很大的灵活性与适用性。笔者认为,相较于进行单一的主动源面波测量或被动源面波测量,在地震勘探中进行混合源面波测量具有建设性意义。
Passive surface-wave utilization has been intensively studied as a means of compensating for the shortage of low-frequency information in active surface-wave measurement. In general, passive surface-wave methods cannot provide phase velocities up to several tens of hertz; thus, active surface-wave methods are often required in order to increase the frequency range. To reduce the amount of field work, we propose a strategy for a high-frequency passive surface-wave survey that imposes active sources during continuous passive surface-wave observation; we call our strategy ‘‘mixed-source surface-wave(MSW)measurement." Short-duration(within 10 min) passive surface waves and mixed-source surface waves were recorded at three sites with different noise levels: namely, inside a school, along a road, and along a railway. Spectral analysis indicates that the high-frequency energy is improved by imposing active sources during continuous passive surface-wave observation. The spatial autocorrelation(SPAC) method and the multichannel analysis of passive surface waves(MAPS) method based on cross-correlations were performed on the recorded time sequences. The results demonstrate the flexibility and applicability of the proposed method for high-frequency phase velocity analysis. We suggest that it will be constructive to perform MSW measurement in a seismic investigation, rather than exclusively performing either active surface-wave measurement or passive surface-wave measurement.
Passive surface-wave utilization has been intensively studied as a means of compensating for the shortage of low-frequency information in active surface-wave measurement. In general, passive surface-wave methods cannot provide phase velocities up to several tens of hertz; thus, active surface-wave methods are often required in order to increase the frequency range. To reduce the amount of field work, we propose a strategy for a high-frequency passive surface-wave survey that imposes active sources during continuous passive surface-wave observation; we call our strategy ‘‘mixed-source surface-wave(MSW)measurement." Short-duration(within 10 min) passive surface waves and mixed-source surface waves were recorded at three sites with different noise levels: namely, inside a school, along a road, and along a railway. Spectral analysis indicates that the high-frequency energy is improved by imposing active sources during continuous passive surface-wave observation. The spatial autocorrelation(SPAC) method and the multichannel analysis of passive surface waves(MAPS) method based on cross-correlations were performed on the recorded time sequences. The results demonstrate the flexibility and applicability of the proposed method for high-frequency phase velocity analysis. We suggest that it will be constructive to perform MSW measurement in a seismic investigation, rather than exclusively performing either active surface-wave measurement or passive surface-wave measurement.
引文
[1] Yoon S. Combined active-passive surface wave measurements at five sites in the western and southern US. KSCE J Civ Eng 2011;15(5):823–30.
[2] Song YY, Castagna JP, Black RA, Knapp RW. Sensitivity of near-surface shearwave velocity determination from Rayleigh and Love waves. SEG Expanded Abst 1989;8(1):1357.
[3] Park CB, Miller RD, Xia J. Multichannel analysis of surface waves. Geophysics1999;64(3):800–8.
[4] Xia J, Miller RD, Park CB. Estimation of near-surface shear-wave velocity by inversion of Rayleigh waves. Geophysics 1999;64(3):691–700.
[5] Xia J, Miller RD, Park CB; Kansas Geological Survey. Advantages of calculating shear wave velocity from surface waves with higher modes. In:SEG technical program expanded abstracts 2000. Tulsa:Society of Exploration Geophysicists;2000. p. 1295–8.
[6] Xia J, Miller RD, Park CB, Tian G. Inversion of high frequency surface waves with fundamental and higher modes. J Appl Geophys 2003;52(1):45–57.
[7] Hayashi K, Suzuki H. CMP cross-correlation analysis of multi-channel surfacewave data. Explor Geophys 2004;35(1):7–13.
[8] Okada H, Suto K. The microtremor survey method. Tulsa:Society of Exploration Geophysicists; 2003.
[9] Aki K. Space and time spectra of stationary stochastic waves, with special reference to micro-tremors. Bull Earthquake Res Inst 1957;35:415–56.
[10] Asten MW. Site shear velocity profile interpretation from microtremor array data by direct fitting of SPAC curves. In:Proceedings of the Third International Symposium on the Effects of Surface Geology on Seismic Motion; 2006 Aug30–Sep 1; Grenoble, France; 2006.
[11] Xu Y, Zhang B, Luo Y, Xia J. Surface-wave observations after integrating active and passive source data. Leading Edge 2013;32(6):634–7.
[12] Louie JN. Faster, better:shear-wave velocity to 100 meters depth from refraction microtremor arrays. Bull Seismol Soc Am 2001;91(2):347–64.
[13] Park C, Miller R, Laflen D, Neb C, Ivanov J, Bennett B, et al. Imaging dispersion curves of passive surface waves. SEG Expanded Abst2004;1:1357–60.
[14] Cheng F, Xia J, Luo Y, Xu Z, Wang L, Shen C, et al. Multi-channel analysis of passive surface waves based on cross-correlations. Geophysics 2016;81(5):EN57–66.
[15] Yoon S, Rix GJ. Combined active-passive surface wave measurements for nearsurface site characterization. In:Proceedings of the Symposium on the Application of Geophysics to Engineering and Environmental Problems2004; 2004 Feb 22–26; Colorado Springs, CO. USA. Denver:Environment and Engineering Geophysical Society; 2004. p. 1556–64.
[16] Liu Y, Bay J, Luke B, Louie J, Pullammanappallil S. Combining active-and passive-source measurements to profile shear wave velocities for seismic microzonation. In:Proceedings of the Geo-Frontiers Congress 2005; 2005 Jan24–26; Austin, TX, USA; 2005.
[17] Park CB, Miller RD, Ryden N, Xia J, Ivanov J. Combined use of active and passive surface waves. J Environ Eng Geophys 2005;10(3):323–34.
[18] Hayashi K, Cakir R, Walsh TJ, State W. Comparison of dispersion curves and velocity models obtained by active and passive surface wave methods. In:Proceedings of the 2016 SEG Annual Meeting; 2016 Oct 16–21; Dallas, TX,USA; 2016. p. 4983–8.
[19] Aki K. A note on the use of microseisms in determining the shallow structures of the earth’s crust. Geophysics 1965;30(4):665–6.
[20] Ohori M, Nobata A, Wakamatsu K. A comparison of ESAC and FK methods of estimating phase velocity using arbitrarily shaped microtremor arrays. Bull Seismol Soc Am 2002;92(6):2323–32.
[21] Weemstra C, Boschi L, Goertz A, Artman B. Seismic attenuation from recordings of ambient noise. Geophysics 2013;78(1):Q1–14.
[22] Asten MW. On bias and noise in passive seismic data from finite circular array data processed using SPAC methods. Geophysics 2006;71(6):V153–62.
[23] Chávez-García FJ, Luzón F. On the correlation of seismic microtremors. J Geophys Res 2005;110:1–12.
[24] Chávez-García FJ, Rodríguez M, Stephenson WR. Subsoil structure using SPAC measurements along a line. Bull Seismol Soc Am 2006;96(2):729–36.
[25] Cheng F, Xia J, Xu Y, Xu Z, Pan Y. A new passive seismic method based on seismic interferometry and multichannel analysis of surface waves. J Appl Geophys 2015;117:126–35.
[26] Luo Y, Xia J, Miller RD, Xu Y, Liu J, Liu Q. Rayleigh-wave dispersive energy imaging using a high-resolution linear radon transform. Pure Appl Geophys2008;165(5):903–22.
[27] Xia J, Xu Y, Chen C, Kaufmann RD, Luo Y. Simple equations guide highfrequency surface-wave investigation techniques. Soil Dyn Earthquake Eng2006;26(5):395–403.
[28] Pan Y, Xia J, Zeng C. Verification of correctness of using real part of complex root as Rayleigh-wave phase velocity with synthetic data. J Appl Geophys2013;88:94–100.
[29] Bensen GD, Ritzwoller MH, Barmin MP, Levshin AL, Lin F, Moschetti MP, et al.Processing seismic ambient noise data to obtain reliable broadband surface wave dispersion measurements. Geophys J Int 2007;169(3):1239–60.
[30] Chimoto K, Yamanaka H. Effects of the durations of crosscorrelated microtremor records on broadband dispersion measurements using seismic interferometry. Geophysics 2014;79(3):Q11–9.
[31] Yoon S, Rix GJ. Near-field effects on array-based surface wave methods with active sources. J Geotech Geoenviron Eng 2009;135(3):399–406.
[32] Lin CP, Lin CH. Effect of lateral heterogeneity on surface wave testing:numerical simulations and a countermeasure. Soil Dyn Earthquake Eng2007;27(6):541–52.
[2] Song YY, Castagna JP, Black RA, Knapp RW. Sensitivity of near-surface shearwave velocity determination from Rayleigh and Love waves. SEG Expanded Abst 1989;8(1):1357.
[3] Park CB, Miller RD, Xia J. Multichannel analysis of surface waves. Geophysics1999;64(3):800–8.
[4] Xia J, Miller RD, Park CB. Estimation of near-surface shear-wave velocity by inversion of Rayleigh waves. Geophysics 1999;64(3):691–700.
[5] Xia J, Miller RD, Park CB; Kansas Geological Survey. Advantages of calculating shear wave velocity from surface waves with higher modes. In:SEG technical program expanded abstracts 2000. Tulsa:Society of Exploration Geophysicists;2000. p. 1295–8.
[6] Xia J, Miller RD, Park CB, Tian G. Inversion of high frequency surface waves with fundamental and higher modes. J Appl Geophys 2003;52(1):45–57.
[7] Hayashi K, Suzuki H. CMP cross-correlation analysis of multi-channel surfacewave data. Explor Geophys 2004;35(1):7–13.
[8] Okada H, Suto K. The microtremor survey method. Tulsa:Society of Exploration Geophysicists; 2003.
[9] Aki K. Space and time spectra of stationary stochastic waves, with special reference to micro-tremors. Bull Earthquake Res Inst 1957;35:415–56.
[10] Asten MW. Site shear velocity profile interpretation from microtremor array data by direct fitting of SPAC curves. In:Proceedings of the Third International Symposium on the Effects of Surface Geology on Seismic Motion; 2006 Aug30–Sep 1; Grenoble, France; 2006.
[11] Xu Y, Zhang B, Luo Y, Xia J. Surface-wave observations after integrating active and passive source data. Leading Edge 2013;32(6):634–7.
[12] Louie JN. Faster, better:shear-wave velocity to 100 meters depth from refraction microtremor arrays. Bull Seismol Soc Am 2001;91(2):347–64.
[13] Park C, Miller R, Laflen D, Neb C, Ivanov J, Bennett B, et al. Imaging dispersion curves of passive surface waves. SEG Expanded Abst2004;1:1357–60.
[14] Cheng F, Xia J, Luo Y, Xu Z, Wang L, Shen C, et al. Multi-channel analysis of passive surface waves based on cross-correlations. Geophysics 2016;81(5):EN57–66.
[15] Yoon S, Rix GJ. Combined active-passive surface wave measurements for nearsurface site characterization. In:Proceedings of the Symposium on the Application of Geophysics to Engineering and Environmental Problems2004; 2004 Feb 22–26; Colorado Springs, CO. USA. Denver:Environment and Engineering Geophysical Society; 2004. p. 1556–64.
[16] Liu Y, Bay J, Luke B, Louie J, Pullammanappallil S. Combining active-and passive-source measurements to profile shear wave velocities for seismic microzonation. In:Proceedings of the Geo-Frontiers Congress 2005; 2005 Jan24–26; Austin, TX, USA; 2005.
[17] Park CB, Miller RD, Ryden N, Xia J, Ivanov J. Combined use of active and passive surface waves. J Environ Eng Geophys 2005;10(3):323–34.
[18] Hayashi K, Cakir R, Walsh TJ, State W. Comparison of dispersion curves and velocity models obtained by active and passive surface wave methods. In:Proceedings of the 2016 SEG Annual Meeting; 2016 Oct 16–21; Dallas, TX,USA; 2016. p. 4983–8.
[19] Aki K. A note on the use of microseisms in determining the shallow structures of the earth’s crust. Geophysics 1965;30(4):665–6.
[20] Ohori M, Nobata A, Wakamatsu K. A comparison of ESAC and FK methods of estimating phase velocity using arbitrarily shaped microtremor arrays. Bull Seismol Soc Am 2002;92(6):2323–32.
[21] Weemstra C, Boschi L, Goertz A, Artman B. Seismic attenuation from recordings of ambient noise. Geophysics 2013;78(1):Q1–14.
[22] Asten MW. On bias and noise in passive seismic data from finite circular array data processed using SPAC methods. Geophysics 2006;71(6):V153–62.
[23] Chávez-García FJ, Luzón F. On the correlation of seismic microtremors. J Geophys Res 2005;110:1–12.
[24] Chávez-García FJ, Rodríguez M, Stephenson WR. Subsoil structure using SPAC measurements along a line. Bull Seismol Soc Am 2006;96(2):729–36.
[25] Cheng F, Xia J, Xu Y, Xu Z, Pan Y. A new passive seismic method based on seismic interferometry and multichannel analysis of surface waves. J Appl Geophys 2015;117:126–35.
[26] Luo Y, Xia J, Miller RD, Xu Y, Liu J, Liu Q. Rayleigh-wave dispersive energy imaging using a high-resolution linear radon transform. Pure Appl Geophys2008;165(5):903–22.
[27] Xia J, Xu Y, Chen C, Kaufmann RD, Luo Y. Simple equations guide highfrequency surface-wave investigation techniques. Soil Dyn Earthquake Eng2006;26(5):395–403.
[28] Pan Y, Xia J, Zeng C. Verification of correctness of using real part of complex root as Rayleigh-wave phase velocity with synthetic data. J Appl Geophys2013;88:94–100.
[29] Bensen GD, Ritzwoller MH, Barmin MP, Levshin AL, Lin F, Moschetti MP, et al.Processing seismic ambient noise data to obtain reliable broadband surface wave dispersion measurements. Geophys J Int 2007;169(3):1239–60.
[30] Chimoto K, Yamanaka H. Effects of the durations of crosscorrelated microtremor records on broadband dispersion measurements using seismic interferometry. Geophysics 2014;79(3):Q11–9.
[31] Yoon S, Rix GJ. Near-field effects on array-based surface wave methods with active sources. J Geotech Geoenviron Eng 2009;135(3):399–406.
[32] Lin CP, Lin CH. Effect of lateral heterogeneity on surface wave testing:numerical simulations and a countermeasure. Soil Dyn Earthquake Eng2007;27(6):541–52.