Horizontal slices of estimated lateral velocity resolution at depths between 1 and 12 km using the method of Zelt (1998). The contour interval is 5 km. The heavy black line is the 20 km contour. Contours for lateral resolution < 20 km are white. For clarity, contours are omitted in the z = 1 panel. Black regions have a better than 5 km resolution; white regions have a worse than 30 km resolution or are unsampled. Dots are receiver locations.