1. A method for processing seismic data to produce a velocity model and a depth image, said method comprising: a) acquiring the seismic data; b) generating a shallow velocity model from the seismic data; c) generating a stacking velocity model using the shallow velocity model as a guide; d) generating an initial interval velocity model from the stacking velocity model; e) generating an initial depth image using the initial interval velocity model; f) identifying at least one depth image horizon in the initial depth image to determine initial interpreted interfaces, wherein said depth image horizon correspond to stack data horizons identified in stack data; g) calculating initial inverted interfaces with a computer using the initial interval velocity model, wherein the initial inverted interfaces are inverted stack data horizons; and h) performing a first congruency test on the initial interpreted interfaces and the initial inverted interfaces to determine a final depth image and a final velocity model for generating a geologic image that is displayed on a display.