The Flow of Water into the Deep Sea Basins of the Western South Pacific Ocean

Abstract

The hydrographic conditions in the deep sea basins of the western South Pacific Ocean are analysed using relations between potential temperature and salinity, based on observations made from H.M.A.S. Gascoyne in 1960. It is shown that the bottom waters in the Coral Sea Basin and in the Solomon Basin are both characterized by a comparatively high salinity and that they come from the East Australian Basin. The bottom waters in the New Hebrides Basin, the New Caledonia Trough, and the Fiji Basin come from the central Pacific Basin. The water in the New Hebrides Basin and that in the New Caledonia Trough both have a slight admixture of water of higher salinity which has escaped over the ridges on the east sides of the Coral Sea Basin and the Solomon Basin. The Coral Sea Basin and the Solomon Basin considered as a unit is an example, probably the unique case, of . the inflow into a basin occurring at a higher level than the outflow. The sill depths of the different basins are determined by using potential temperature characteristics. The water exchange of the Coral Sea Basin is discussed theoretically. The upward velocity at depths between 3000 and 4000 m is of the order of 1.5 × 10-5 cm/sec and the rate of inflow 0.04 million m3/sec.