Figure 2 shows the distribution of surface temperature observed by thermograph at 4 m of depth. When analyzed together with the hydrographic profiles evidence of gradients of declining temperature shorewards demonstrates upwelling. Figure 3 shows the distribution of temperature, salinity and oxygen in the profiles. The lowest surface temperatures are found inshore in the east off the Paria Peninsula which indicate upwelling in this area. The profile off Cabo Tres Puntas shows when compared with those of the previous surveys that the upwelling is only moderate as compared with February and May, but somewhat more intensive than in August. The salinity observations demonstrate the presence in the surface offshore of low-salinity water as in Survey 3. This is presumably of Orinoco origin. In the Cariaco Trench profile there is a slight gradient shorewards in the surface temperature. Conditions below the threshold at about 200 m are the same as observed previously. Also the profiles worked east of La Guaira and off Pta. Sabana show some lifting of the isolines shorewards together with a trend of decline in the temperature of the surface layer. The hydrographic situation in the Gulf of Venezuela appears to be similar to that observed in June.
