1887
Volume 64, Issue 1
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Recently, an effective and powerful approach for simulating seismic wave propagation in elastic media with an irregular free surface was proposed. However, in previous studies, researchers used the periodic condition and/or sponge boundary condition to attenuate artificial reflections at boundaries of a computational domain. As demonstrated in many literatures, either the periodic condition or sponge boundary condition is simple but much less effective than the well‐known perfectly matched layer boundary condition. In view of this, we intend to introduce a perfectly matched layer to simulate seismic wavefields in unbounded models with an irregular free surface. We first incorporate a perfectly matched layer into wave equations formulated in a frequency domain in Cartesian coordinates. We then transform them back into a time domain through inverse Fourier transformation. Afterwards, we use a boundary‐conforming grid and map a rectangular grid onto a curved one, which allows us to transform the equations and free surface boundary conditions from Cartesian coordinates to curvilinear coordinates. As numerical examples show, if free surface boundary conditions are imposed at the top border of a model, then it should also be incorporated into the perfectly matched layer imposed at the top‐left and top‐ right corners of a 2D model where the free surface boundary conditions and perfectly matched layer encounter; otherwise, reflections will occur at the intersections of the free surface and the perfectly matched layer, which is confirmed in this paper. So, by replacing normal second derivatives in wave equations in curvilinear coordinates with free surface boundary conditions, we successfully implement the free surface boundary conditions into the perfectly matched layer at the top‐left and top‐right corners of a 2D model at the surface. A number of numerical examples show that the perfectly matched layer constructed in this study is effective in simulating wave propagation in unbounded media and the algorithm for implementation of the perfectly matched layer and free surface boundary conditions is stable for long‐time wavefield simulation on models with an irregular free surface.

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2015-12-15
2024-04-20
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References

  1. AltermanZ. and KaralF.1968. Propagation of elastic waves in layered media by finite difference methods. Bulletin of the Seismological Society of America58, 367–398.
    [Google Scholar]
  2. AltermanZ. and RotenbergA.1969. Seismic waves in a quarter plane. Bulletin of the Seismological Society of America59, 347–368.
    [Google Scholar]
  3. AppeloD. and PeterssonN.2009. A stable finite‐difference method for the elastic wave equation on complex geometries with free surfaces. Communications in Computational Physics5, 84–107.
    [Google Scholar]
  4. BerengerJ.P.1994. A perfectly matched layer for the absorption of electromagnetic waves. Journal of computational physics114, 185–200.
    [Google Scholar]
  5. CerjanC., KosloffD., KosloffR. and ReshefM.1985. A non‐reflecting boundary condition for discrete acoustic and elastic wave equations. Geophysics50, 705–708.
    [Google Scholar]
  6. ChenJ.2011. Application of the nearly perfectly matched layer for seismic wave propagation in 2D homogeneous isotropic media. Geophysical Prospecting59, 662–672.
    [Google Scholar]
  7. ChewW. and LiuQ.1996. Perfectly matched layers for elastodynamics: A new absorbing boundary condition. Journal of Computational Acoustics4, 341–359.
    [Google Scholar]
  8. ClaytonR. and EngquistB.1977. Absorbing boundary conditions for acoustic and elastic wave equations. Bulletin of the Seismological Society of America67, 1529–1540.
    [Google Scholar]
  9. CollinoF. and MonkP.B.1998. Optimizing the perfectly matched layer. Computer Methods in Applied Mechanics and Engineering164(1,2), 157–171.
    [Google Scholar]
  10. CollinoF. and TsogkaC.2001. Application of the perfectly matched absorbing layer model to the linear elastodynamic problem in anisotropic heterogeneous media. Geophysics66, 294–307.
    [Google Scholar]
  11. EngquistB. and MajdaA.1977. Absorbing boundary conditions for the numerical simulation of waves. Mathematics of Computation31, 629–651.
    [Google Scholar]
  12. FornbergB.1988. The pseudo‐spectral method: Accurate representation in elastic wave calculations. Geophysics53, 625–637.
    [Google Scholar]
  13. GuddatiM.N. and LimK.W.2006. Continued fraction absorbing boundary conditions for convex polygonal domains. International Journal for Numerical Methods in Engineering66, 949–977.
    [Google Scholar]
  14. HestholmS. and RuudB.1994. 2‐D finite‐difference elastic wave modeling including surface topography. Geophysical Prospecting42, 371–390.
    [Google Scholar]
  15. HestholmS. and RuudB.1998. 3‐D finite‐difference elastic wave modeling including surface topography. Geophysics63, 613–622.
    [Google Scholar]
  16. HvidS.L.1994. Three‐dimensional algebraic grid generation. PhD thesis, Technical University of Denmark.
    [Google Scholar]
  17. JihR., McLaughlinK. and DerZ.1988. Free‐boundary conditions of arbitrary polygonal topography in a two‐dimensional explicit elastic finite‐difference scheme. Geophysics53, 1045–1055.
    [Google Scholar]
  18. KantartzisN.V.2003. Generalised higher‐order FDTD‐PML algorithm for enhanced analysis of 3‐D waveguiding EMC structures in curvilinear coordinates. IEEE Proceedings on Microwaves, Antennas and Propagation, 150(5), 351–359.
    [Google Scholar]
  19. KomatitschD. and MartinR.2007. An unsplit convolutional perfectly matched layer improved at grazing incidence for the seismic wave equation. Geophysics72, SM155–SM167.
    [Google Scholar]
  20. KomatitschD. and TrompJ.2003. A perfectly matched layer absorbing boundary condition for the second‐order seismic wave equation. Geophysical Journal International154, 146–153.
    [Google Scholar]
  21. KristekJ., MoczoP. and ArchuletaR.J.2002. Efficient methods to simulate planar free surface in the 3D 4th‐order staggered‐grid finite‐difference schemes. Studia Geophysica et Geodaetica46, 355–381.
    [Google Scholar]
  22. LanH. and ZhangZ.2011a. Three‐dimensional wavefield simulation in heterogeneous transversely isotropic medium with irregular free surface. Bulletin of the Seismological Society of America101, 1354–1370.
    [Google Scholar]
  23. LanH. and ZhangZ.2011b. Comparative study of the free‐surface boundary condition in two‐dimensional finite‐difference elastic wavefield simulation. Journal of Geophysics and Engineering8, 275–286.
    [Google Scholar]
  24. LanH. and ZhangZ.2012. Seismic wavefield modeling in media with fluid‐filled fractures and surface topography. Applied Geophysics9, 301–312.
    [Google Scholar]
  25. LiuY., TengJ., LanH., SiX. and MaX.2014. A comparative study of finite element and spectral element methods in seismic wavefield modeling. Geophysics79(2), T91–T104.
    [Google Scholar]
  26. LombardB., PirauxJ., GélisC. and VirieuxJ.2008. Free and smooth boundaries in 2‐D finite‐difference schemes for transient elastic waves. Geophysical Journal International172, 252–261.
    [Google Scholar]
  27. MartinR. and KomatitschD.2009. An unsplit convolutional perfectly matched layer technique improved at grazing incidence for the viscoelastic wave equation. Geophysical Journal International179, 333–344.
    [Google Scholar]
  28. MurG.1981. Absorbing boundary conditions for the finite‐difference approximation of the time‐domain electromagnetic field equations. IEEE Transactions on Electromagnetic Compatibility23, 377–382.
    [Google Scholar]
  29. RaoY. and WangY.2013. Seismic waveform simulation with pseudo‐orthogonal grids for irregular topographic models. Geophysical Journal International.
    [Google Scholar]
  30. RodenJ.A. and GedneyS.D.2000. Convolutional PML (CPML): An efficient FDTD implementation of the CFS‐PML for arbitrary media. Microwave and Optical Technology Letters27, 334–339.
    [Google Scholar]
  31. Sanchez‐SesmaF.J., BravoM.A. and HerrearI.1985. Surface motion of topographical irregularities for incident P, SV, and Rayleigh waves. Bulletin of the Seismological Society of America75, 263–269.
    [Google Scholar]
  32. TeixeiraF.L. and ChewW.C.2000. Complex space approach to perfectly matched layers: A review and some new developments. International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 13(5), 441–455.
    [Google Scholar]
  33. TianX., KangI., KimG. and ZhangH.2008. An improvement in the absorbing boundary technique for numerical simulation of elastic wave propagation. Journal of Geophysics and Engineering5, 203–209.
    [Google Scholar]
  34. WongH.1982. Effect of surface topography on the diffraction of P, SV, and Rayleigh waves. Bulletin of the Seismological Society of America72, 1167–1183.
    [Google Scholar]
  35. YangD., WangS., ZhangZ. and TengJ.2003. n‐Times absorbing boundary conditions for compact finite‐difference modeling of acoustic and elastic wave propagation in the 2D TI medium. Bulletin of the seismological society of America93, 2389–2401.
    [Google Scholar]
  36. ZengY.Q. and LiuQ.H.2001. A staggered‐grid finite‐difference method with perfectly matched layers for poroelastic wave equations. The Journal of the Acoustical Society of America109, 2571–2580.
    [Google Scholar]
  37. ZhangW. and ChenX.2006. Traction image method for irregular free surface boundaries in finite difference seismic wave simulation. Geophysical Journal International167, 337–353.
    [Google Scholar]
  38. ZhengY. and HuangX.2002. Anisotropic perfectly matched layers for elastic waves in Cartesian and curvilinear coordinates. MIT Report, 77843–73368. URI: http://hdl.handle.net/1721.1/67857
    [Google Scholar]
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