Prestack depth migration (PSDM) analysis has the potential to significantly improve the accuracy of both shallow seismic reflection images and the measured velocity distributions. In a study designed to image faults in the Alvord Basin, Oregon, at depths from 25–1000 m, PSDM produced a detailed reflection image over the full target depth range. In contrast, poststack time migration produced significant migration artifacts in the upper 100 m that obscured reflection events and limited the structural interpretation in the shallow section. Additionally, an abrupt increase from ~2500 to >3000 m/s in the PSDM velocity model constrained the interpretation of the transition from sedimentary basin fill to basement volcanic rocks. PSDM analysis revealed a complex extensional history with at least two distinct phases of basin growth and a midbasin basement high that forms the division between two major basin compartments.
This document was originally published by Society of Exploration Geophysicists in Geophysics. Copyright restrictions may apply. DOI: 10.1190/1.2335659
Bradford, John H.; Liberty, Lee M.; Lyle, Mitchell W.; Clement, William P.; and Hess, Scott. (2006). "Imaging Complex Structure in Shallow Seismic-reflection Data Using Prestack Depth Migration". Geophysics, 71(6), . http://dx.doi.org/10.1190/1.2335659