a)| j | in a cut through the depth (solid) and across the width (dashed) of the current layer in the plane z = 0.5 with asterisks and diamonds representing the values of the current contour used to determine the depth and the width of the current layer at this cut for the contour method and the crosses and triangles for the FWHM method, respectively. b) Outline of the depth and c) width of the current layer. The colours represent initial current j_sep = 0.75 (black), 1.00 (blue), 1.25 (green), 1.5 (orange) and 1.75 (red).