Evolution of the traveltime misfit, F^T, the amplitude misfit, F^A and the total misfit, F= (F^T+F^A)/2, as a function of iteration number; iteration 0 corresponds to the starting models, and iteration four to the final models. The rows correspond to inversions based on direct P-wave traveltimes anomalies, direct P- and S-wave traveltime anomalies and direct P- and S-wave traveltime and amplitude anomalies, as indicated. The dotted line identifies a misfit of one.