Surface waves and guided P-waves,as two boundary-related wave phenomena,are a crucial part of the near-surface seismic wave field.This study investigated their generation mechanism and propagation regularity using the high-order staggered-grid finite-difference algorithm.First,it solved the problems like numerical dispersion and boundary conditions in numerical simulation.Based on this,it designed medium models under different thicknesses and elastic parameters for forward modeling.Furthermore,it extracted dispersion profiles and amplitude versus offset curves for analysis.In the case of a low-velocity thin layer on the surface,guided P-waves can be generated when the phase velocities of P and SV waves from the same source exceed the S-wave velocity but are less than the P-wave velocity of the underlying high-velocity layer.In media with high Poisson's ratios(>0.4),the phase velocities of surface waves and guided P-waves are sensitive to the S- and P-wave velocities,respectively.Surface waves and guided P-waves usually contain near-surface information that is unavailable in refracted and reflected waves.The appropriate acquisition,analysis,and inversion of near-surface information enable the establishment of a high-resolution near-surface model.This study generalized the generation conditions and wave field characteristics of surface waves and guided P-waves under the same source and deepened the understanding of their propagation regularity,laying a foundation for inversion and denoising research.
刘童, 孙成禹, 蔡瑞乾. 地震面波和P—导波正演模拟与波场分析[J]. 物探与化探, 2024, 48(4): 986-995.
LIU Tong, SUN Cheng-Yu, CAI Rui-Qian. Forward modeling and wave field analysis of seismic surface waves and guided P-waves. Geophysical and Geochemical Exploration, 2024, 48(4): 986-995.
Wu H, Li Q C, Shao G Z. Development status and prospect of Rayleigh waveform inversion[J]. Geophysical and Geochemical Exploration, 2018, 42(6):1103-1111.
[3]
Sun C Y, Wang Z N, Wu D S, et al. A unified description of surface waves and guided waves with relative amplitude dispersion maps[J]. Geophysical Journal International, 2021, 227(3):1480-1495.
[4]
Wang Z J, Xiao J Y, Li D, et al. Full waveform inversion guided wave tomography with a recurrent neural network[J]. Ultrasonics, 2023, 133:107043.
[5]
Rayleigh L. On waves propagated along the plane surface of an elastic solid[J]. Proceedings of the London Mathematical Society, 1885,s1- 17(1):4-11.
[6]
Leslie D M, Evans B. The cause and effects of multilayer-generated guided-waves[J]. Exploration Geophysics, 2000, 31(4):543-551.
[7]
Alterman Z S, Karal F C J. Propagation of elastic waves in layered media by finite difference methods[J]. The Bulletin of the Seismological Society of America, 1969, 59(1):471.
[8]
Boore D. Finite difference methods for seismic wave propagation in heterogeneous materials[M]// Methods in computational physics: Advances in Research and Applications. Amsterdam:Elsevier, 1972:1-37.
[9]
Madariaga R. Dynamics of an expanding circular fault[J]. The Bulletin of the Seismological Society of America, 1976, 66(3):639-666.
[10]
Jean V. SH-wave propagation in heterogeneous media:Velocity-stress finite-difference method[J]. Geophysics, 1984, 49(11):1933.
[11]
Jean V. P-SV wave propagation in heterogeneous media:Velocity-stress finite-difference method[J]. Geophysics, 1986, 51(4):889-901.
[12]
Levander A R. Fourth-order finite-difference P-SV seismograms[J]. Geophysics, 1988, 53(11):1425.
Dong L G, Ma Z T, Cao J Z, et al. A staggered-grid high-order difference method of one-order elastic wave equation[J]. Chinese Journal of Geophysics, 2000, 43(3):411-419.
[14]
Collino F, Tsogka C. Application of the perfectly matched absorbing layer model to the linear elastodynamic problem in anisotropic heterogeneous media[J]. Geophysics, 2001, 66(1):294.
Zhang W, Gan F P, Liu W, et al. Rayleigh surface wave modeling by finite difference method in biphasic media[J]. Geophysical and Geochemical Exploration, 2014, 38(6):1275-1283.
Lian X M, Zhang R X. Parallel strategy of large-scale 3D seismic forward by finite difference method on GPU cluster[J]. Geophysical and Geochemical Exploration, 2015, 39(3):615-620.
Peng G X, Liu W, Guo N M, et al. A time-space domain dispersion-relationship-based staggered-grid finite-difference scheme for modeling the stress-velocity acoustic wave equation[J]. Geophysical Prospecting for Petroleum, 2022, 61(1):156-165,173.
doi: 10.3969/j.issn.1000-1441.2022.01.016
[18]
Pekeris C L. Theory of propagation of explosive sound in shallow water[J]. Geological Society of America Memoirs, 1948, 27(1):1-116.
[19]
Robertsson J O A, Holliger K, Green A G, et al. Effects of near-surface waveguides on shallow high-resolution seismic refraction and reflection data[J]. Geophysical Research Letters, 1996, 23(5):495-498.
[20]
Sheriff R E, Geldart L P. Exploration seismology(2nd ed)[M]. Cambridge: Cambridge University Press, 1995.
[21]
Roth M, Holliger K. Joint inversion of Rayleigh and guided waves in high-resolution seismic data using a genetic algorithm[C]// SEG Technical Program Expanded Abstracts 1998.Society of Exploration Geophysicists, 1998:1570-1573.
[22]
Herman G C, Milligan P A, Huggins R J, et al. Imaging shallow objects and heterogeneities with scattered guided waves[J]. Geophysics, 2000, 65(1):247.
[23]
Carcione J M, Helle H B. The physics and simulation of wave propagation at the ocean bottom[J]. Geophysics, 2004, 69(3):825-839.
[24]
Klein G, Bohlen T, Theilen F, et al. Acquisition and inversion of dispersive seismic waves in shallow marine environments[J]. Marine Geophysical Researches, 2005, 26(2):287-315.
[25]
Ernst F E. Long-wavelength statics estimation from guided waves[C]// London:69th EAGE Conference and Exhibition incorporating SPE EUROPEC 2007,European Association of Geoscientists & Engineers, 2007:1-5.
[26]
李正波. 频率贝塞尔变换法提取地震记录中的频散信息[D]. 合肥: 中国科学技术大学, 2020.
[26]
Li Z B. Frequency-Bessel transform method for extracting dispersion information from seismic records[D]. Hefei: University of Science and Technology of China, 2020.
Liu H, Li J, Zeng Z F, et al. Stochastic inversion of surface wave dispersion curves based on Bayesian theory[J]. Geophysical and Geochemical Exploration, 2021, 45(4):951-960.
[28]
Boerner D E, West G F. A generalized representation of the electromagnetic fields in a layered earth[J]. Geophysical Journal International, 1989, 97(3):529-547.
[29]
Collino F. Perfectly matched absorbing layers for the paraxial equations[J]. Journal of Computational Physics, 1997, 131(1):164-180.
[30]
Roth M, Holliger K. Inversion of source-generated noise in high-resolution seismic data[J]. The Leading Edge, 1999, 18(12):1402-1406.
[31]
Robertsson J O A. A numerical free-surface condition for elastic/viscoelastic finite-difference modeling in the presence of topography[J]. Geophysics, 1996, 61(6):1921-1934.
Dong L G, Ma Z T. A study on stability of the staggered-grid high-order difference method of first-order elastic wave equation[J]. Chinese Journal of Geophysics, 2000, 43(6):856-864.
Wu D S, Sun C Y, Lin M Y. Activeseismic surface wave dispersion imaging method based on cross-correlation and phase-shifting[J]. Progress in Geophysics, 2017, 32(4):1693-1700.
Xiong L, Sun C Y, Cai R Q. Forward wavefield modeling of seismic surface waves under cylindrical symmetry[J]. Oil Geophysical Prospecting, 2023, 58(1):133-144.
[35]
Buchen P W, Ben-Hador R. Free-mode surface-wave computations[J]. Geophysical Journal International, 1996, 124(3):869-887.
Qiu X M, Wang Y, Wei Y X, et al. Advancements in multi-component surface waves:A review[J]. Geophysical Prospecting for Petroleum, 2021, 60(1):46-56.
doi: 10.3969/j.issn.1000-1441.2021.01.005
[37]
Shi C W, Ren H X, Chen X F. Dispersion inversion for P- and S-wave velocities based on guided P and Scholte waves[J]. Geophysics, 2023, 88(6):R721-R736.
