The offset-midpoint traveltime pyramid describes the diffraction traveltime of a point diffractor in homogeneous media. We have developed an analytic approximation for the P-wave offset-midpoint traveltime pyramid for homogeneous orthorhombic media. In this approximation, a perturbation method and the Shanks transform were implemented to derive the analytic expressions for the horizontal slowness components of P-waves in orthorhombic media. Numerical examples were shown to analyze the proposed traveltime pyramid formula and determined its accuracy and the application in calculating migration isochrones and reflection traveltime. The proposed offset-midpoint traveltime formula is useful for Kirchhoff prestack time migration and migration velocity analysis for orthorhombic media.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: Q. Hao and A. Stovas thank the Rock Seismic Research Project for financial support. T. Alkhalifah thanks KAUST for its support. We are very grateful to an anonymous associate editor, three anonymous reviewers, and Y. Sripanich for many valuable suggestions.