Cumulative geostrophic transport into the Perth Basin (positive values are northward): above 2000 dbar (upper panel) and below 2000 dbar (lower panel) for the 1995 I5E (solid lines) and the 1987 I5 (dashed lines). Reference levels chosen are described in this text and given by Toole and Warren (1981). Cumulative transport axis values range from -5 Sv to +20 Sv in the upper waters and from 0 to 7 Sv in the deep waters.