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Volume 49 Number 5
  • E-ISSN: 1365-2478

Abstract

Shallow SH‐wave reflections are far from routine, although their study can provide insights into important properties of near‐surface materials that cannot be inferred from P‐wave data alone. Difficulties in separating SH‐wave reflections from Love waves are generally considered the major obstacle to progress in shallow SH‐wave seismic reflection. This may be the case in surveys undertaken at great depths, but it is not necessarily true for reflection data gathered at shallow and ultra‐shallow depths. This paper shows that when SH‐wave data possess wavelengths greater than the thickness of the superficial layer, Love waves are not greatly dispersed. In this case, misinterpretation between parts of reflection hyperbolae and waveguide arrivals is sufficiently limited. In a one‐layer model earth, which well approximates typical situations of the near‐surface underground, the most energetic modes (the lowermost modes) of the dispersed surface waves have a dominant frequency band that falls below the wavelet spectrum of the shallow reflections; therefore, they can be filtered out in the frequency domain. Higher modes, although their spectral content overlaps that of the reflections, exhibit small amplitudes on seismograms and leave strong reflections unaffected.We present field examples from three different sites where we were able to obtain ultra‐shallow reflections (< 3 m) in unconsolidated sediments. The high level of resolution (vertical resolution up to 15 cm) suggests that SH‐wave reflection imaging has the potential to complement other high‐resolution techniques, such as P‐wave reflection and ground‐penetrating radar (GPR) imaging, allowing a better and more complete characterization of the near‐surface environments.

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2008-07-07
2024-04-16

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References

  1. AkiK.I. & RichardsP.G.1980.Quantitative Seismology: Theory and Methods. W.H. Freeman & Co.
     [Google Scholar]
  2. BachrachR. & NurA.1998a. High‐resolution shallow‐seismic experiments in sand, Part I: Water table, fluid flow, and saturation. Geophysics63, 1225–1233.
    [Google Scholar]
  3. BachrachR. & NurA.1998b. Ultra‐shallow seismic reflection in unconsolidated sediments: Rock physics base for data acquisition. 68th SEG meeting, New Orleans, USA, Expanded Abstracts, 866–869.
  4. BakerG.S., SchmeissnerC., SteeplesD.W.1999. Seismic reflection from depths of less than two metres. Geophysical Research Letters26, 279–282.DOI: 10.1029/1998gl900243
     [Google Scholar]
  5. BirkeloB.A., SteeplesD.W., MillerR.D., SophocleousM.A.1987. Seismic‐reflection study of a shallow aquifer during a pumping test. Ground Water25, 703–709.
    [Google Scholar]
  6. GoforthT. & HaywardC.1992. Seismic reflection investigations of a bedrock surface buried under alluvium. Geophysics57, 1217–1227.
    [Google Scholar]
  7. HasbrouckW.P.1991. Four shallow‐depth, shear‐wave feasibility studies. Geophysics56, 1875–1885.
    [Google Scholar]
  8. HunterJ.A., PullanS.E., BurnsR.A., GagneR.M., GoodR.L.1984. Shallow seismic reflection mapping of the overburden–bedrock interface with the engineering seismograph – Some simple techniques. Geophysics49, 1381–1385.
    [Google Scholar]
  9. LoveA.E.H.1911.Some Problems of Geodynamics. Cambridge University Press.
     [Google Scholar]
  10. MilkereitB., StumpelH., RabbelW.1986. Shear wave reflection profiling for near‐surface lignite exploration. Geophysical Prospecting34, 845–855.
    [Google Scholar]
  11. NazarianS., StokoeI.I.K.H., HudsonW.R.1983. Use of spectral analysis of surface waves method for determination of moduli and thicknesses of pavement systems. Transportation Research Record930, 38–45.
    [Google Scholar]
  12. RikitakeT., SatoR., HagiwaraY.1987.Applied Mathematics for Earth Scientists. Terra Scientific Publishing Company.
    [Google Scholar]
  13. SambuelliL. & DeiddaG.P.1998. Trasduttore di onde elastiche con sensibilità incrementata alle onde di taglio. Italian Patent TO98A000030.
  14. SambuelliL. & DeiddaG.P.1999. ‘SwyphoneTM’: A new seismic sensor with increased response to SH‐waves. 5th meeting of the Environmental Engineering Geophysical Society, European Section, Budapest, Hungary, Expanded Abstracts.
  15. SteeplesD.W.1998. Special Issue: Shallow seismic reflection section – Introduction. Geophysics63, 1210–1212.
    [Google Scholar]
  16. SteeplesD.W., GreenA.G., McEvillyT.V., MillerR.D., DollW.E., RectorJ.W.1997. A workshop examination of shallow seismic reflection surveying. The Leading Edge16, 1641–1647.
    [Google Scholar]
  17. StokoeI.I.K.H. & NazarianS.1983. Effectiveness of ground improvements from spectral analysis of surface waves. Proceedings of the 8th European Conference on Soil Mechanics and Foundation Engineering, Expanded Abstracts.
  18. WidessM.B.1973. How thin is a thin bed?Geophysics38, 1176–1180.
    [Google Scholar]
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Some SH‐wave seismic reflections from depths of less than three metres
Geophysical Prospecting 49, 499 (2001); https://doi.org/10.1046/j.1365-2478.2001.00280.x
/content/journals/10.1046/j.1365-2478.2001.00280.x
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