Elastic and acoustic migration comparison on elastic Marmousi-II model using generalized-screen method
Abstract
Imaging the multicomponent data using acoustic wave equation algorithms is simply done by treating the P and S waves as independent scalar waves and by applying the velocity field with Vp and Vs for source and receiver wavefield extrapolations, respectively. Acoustic scheme in elastic data imaging sometimes provides efficiencies in computation. However, perfect separation of the P and S wavefields should be preceded prior to imaging. Even if the multicomponent data are perfectly separated into P and S wavefields, the acoustic wave equation scheme produces correct results only in kinematic. Because acoustic wave propagation does not properly treat all elastic wave propagation issues, such as mode conversions, polarizations and amplitude changes. In this study, we use the synthetic elastic Marmousi-II OBC dataset to compare the results from elastic and acoustic generalized-screen migration algorithm. This one-way wave equation migration uses the Fourier method which extrapolates the wavefield by repeated alternation between the wavenumber and spatial domain, thus it is also named as dual-domain method. The generalized-screen method can handle large scattering angles under large velocity perturbation because the vertical slowness operator is Taylor expanded for higher-order corrections for large velocity contrasts and it produces wide-angle propagation. We applied acoustic algorithm to the pressure data and applied elastic algorithm to the horizontal and vertical geophone data. The elastic results show the exact amplitude and polarity behaviors as well as position accuracy compared with acoustic results.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.S11A2440K
- Keywords:
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- 7215 Earthquake source observations;
- SEISMOLOGYDE: 7260 Theory;
- SEISMOLOGYDE: 7270 Tomography;
- SEISMOLOGYDE: 7290 Computational seismology;
- SEISMOLOGY