Kirchhoff prestack depth migration in simple orthorhombic and triclinic models with differently rotated elasticity tensor: comparison with zero-offset travel-time perturbations

Vaclav Bucha

Summary

We use ray-based Kirchhoff prestack depth migration to calculate migrated sections in simple anisotropic homogeneous velocity models in order to demonstrate the impact of rotation of the tensor of elastic moduli on migrated images. The recorded wave field is generated in velocity models composed of two homogeneous layers separated by a curved interface. The anisotropy of the upper layer is orthorhombic or triclinic with the rotation of the tensor of elastic moduli. We apply the Kirchhoff prestack depth migration to single-layer velocity models with orthorhombic or triclinic anisotropy with a differently rotated tensor of elastic moduli. We show and discuss the errors of the migrated interface caused by incorrect velocity models used for migration. The shifts of zero-offset migrated interface caused by incorrect velocity models are estimated using the linear travel-time perturbations and compared with migrated images. The study is limited to P-waves.

Keywords

3-D Kirchhoff prestack depth migration, anisotropic velocity model, rotation of the tensor of elastic moduli, general elastic anisotropy, orthorhombic anisotropy, triclinic anisotropy, travel-time perturbations

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Seismic Waves in Complex 3-D Structures, 26 (2016), 81-102.