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f Extending the macro model by incorporating fine-layering propagation effects
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 56th EAEG Meeting, Jun 1994, cp-47-00009
- ISBN: 978-90-73781-05-4
Abstract
In seismic migration the elimination of propagation effects from the seismic data plays a major role. A wave propagating through the earth will encounter 'large contrast' boundaries which are separated by sequences of thin layers with smaller contrasts. Usually the propagation effects are quantified by a macro model, which accounts for the large contrast boundaries but suffices with the average velocities -(and densities) of the thin-layering between these boundaries. Hence, the angle-dependent dispersion effects due to internal multiple scattering in finely layered media, which have been studied extensively (O'Doherty and Anstey, 1971 ; Burridge and Chang, 1989; Herrmann and Wapenaar, 1992), are neglected in a macro model. We investigate the possibility of replacing a finely layered medium by a homogeneous, anisotropic, 'effective' medium with anelastic losces, thus mimicking the angle-dependent dispersion effects, and allowing for these effects to be incorporated in a 2-D or 3-D extended macro model for true amplitude migration.