1. n. [Geophysics]

A migration technique for processing seismic data in areas where lateral velocity changes are not too severe, but structures are complex. Time migration has the effect of moving dipping events on a surface seismic line from apparent locations to their true locations in time. The resulting image is shown in terms of traveltime rather than depth, and must then be converted to depth with an accurate velocity model to be compared to well logs.

See: depth migration,  diffraction,  migration,  processing,  velocity