Figure 2 shows the distribution of surface temperature observed with the thermograph at 4 m of depth and the distribution of temperature, salinity and oxygen in the profile. The hydrography of the shelf between Cunene and Tombua is in general dominated by its central position in forming the frontal zone between the Angola - and the Benguela Currents. The frontal formations are also clearly evident in the observations from this survey. The horizontal distribution of temperature shows the quasi-permanent features of the area with the colder water of the Benguela Current moving northwards inside the shelf and a tongue of warmer water from the Angola Current moving towards the south off the shelf. Comparison with earlier cruises at about the same time in 1985 and 1986 shows that the inshore surface water is some 2 °C colder than that found previously. The vertical section worked off Baia dos Tigres shows rise of subsurface water from about 75 m depth towards the surface which together with the water of the Benguela Current causes the cooling of the surface layers observed in the inshore shelf.
