The evaluation of anisotropy parameters is demonstrated in the τ-p (intercept time - horizontal slowness) domain, using pre-stack seismic data. It allows critical slowness, of reflected energy to be identified, from which anisotropic parameters in a target layer can be extracted. However, geometric effects (e.g., horizon dip) can damage the accurate evaluation of the critical slowness, thereby impeding the accuracy of the anisotropy parameters. We simulate pre-stack seismic data from a basin province, featuring “seaward dipping reflector” (SDR) geometries. SDRS are formed by stacked volcanic layers; given the strong velocity contrast between volcanic and host rock, a strongly anisotropic fabric can be introduced. Our simulation delivers synthetic responses through an SDR package, with data in both shot and common-midpoint (CMP) domain supplied to the τ-p transform, include varying anisotropic strengths and dip angle of the uppermost SDR interface. Thus, we consider the accuracy of recovered anisotropy estimates. Our results show that models with similar induced anisotropic fabric but varying interface of uppermost SDR yield different critical slowness and hence, affecting the accuracy of extracting anisotropic parameter values. We propose that anisotropic parameters can be successfully recovered from pre-stack CMP data in the τ-p domain, with accuracy typically better than ±10%.


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  1. Corti, G., Agostini, A., Keir, D., Van Wijk, J., Bastow, I.D. and Ranalli, G.
    [2015] Magma-induced axial subsidence during final-stage rifting: Implications for the development of seaward-dipping reflectors. Geosphere, 11(3), 563–571.
    [Google Scholar]
  2. Diebold, J.B. and Stoffa, P.L.
    [1981] The traveltime equation, tau-p mapping, and inversion of common midpoint data. Geophysics, 46(3), 238–254.
    [Google Scholar]
  3. Guest, W. and Kendall, J.
    [1993] Modelling seismic waveforms in anisotropic inhomogeneous media using ray and Maslov asymptotic theory: applications to exploration seismology. Canadian Journal of Exploration Geophysics, 29(1), 78–92.
    [Google Scholar]
  4. Jelani, M. and Angus, D.
    [2016] Dependency of AVO and AVOA Signature for long-offset P-wave Seismic Reflections in the Vicinity of Volcanic Structures. In: 78th EAGE Conference and Exhibition 2016.
    [Google Scholar]
  5. Landrø, M. and Tsvankin, I.
    [2007] Seismic critical-angle reflectometry: A method to characterize azimuthal anisotropy?Geophysics, 72(3), D41–D50.
    [Google Scholar]
  6. Menzies, M.A.
    [2002] Volcanic rifted margins, 362. Geological Society of America.
    [Google Scholar]
  7. Mutter, J.C., Talwani, M. and Stoffa, P.L.
    [1982] Origin of seaward-dipping reflectors in oceanic crust off the Norwegian margin by subaerial sea-floor spreading. Geology, 10(7), 353–357.
    [Google Scholar]
  8. Planke, S. and Eldholm, O.
    [1994] Seismic response and construction of seaward dipping wedges of flood basalts: Vøring volcanic margin. Journal of Geophysical Research: Solid Earth, 99(B5), 9263–9278.
    [Google Scholar]
  9. Sil, S. and Sen, M.K.
    [2009] Seismic critical-angle anisotropy analysis in the τ-p domain. Geophysics, 74(4), A53–A57.
    [Google Scholar]
  10. Thomsen, L.
    [1986] Weak elastic anisotropy. Geophysics, 51(10), 1954–1966.
    [Google Scholar]

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