lsopycnal geostrophic flow is postulated within the Antarctic Circumpolar Current. The major consequence of this is that a strong source (at least 3 × 106m3sec-1) of water with Antarctic Intermediate Water densities (σ0 = 27.2 to 27.3) and cold, fresh Antarctic Zone characteristics must occur in the southeast Pacific Ocean. This is consistent with the formation of isohaline thermoclines in the Subantarctic Zone of the southeast Pacific....