164 DISCOVERY REPORTS 



At all of the stations below the discontinuity layer the temperature and salinity decrease with depth 

 towards the core of the antarctic intermediate water. 



This outline of the conditions on the first survey leads us to the conclusion that, in the region 

 surveyed, two principal types. of surface-water can be identified. 



(a) The coastal or upwelled water, with a low salinity of 35-00 % or less, and low temperature 

 <i8-o° C, and as a rule without any marked convection layer. 



WS989 

 I 



300 



Fig. 14. Distribution of temperature (° C). Section off Sylvia Hill, 10-11 March 1950, survey I. 



Positions of the stations are shown in Fig. 1. 



STATIONS WS986 



SEA MILES ,„ 



OFFSHORE 



ws«e wswj 

 I 



25 



100 



200- 



300 



Fig. 15. Distribution of salinity (% ). Section off Sylvia Hill, 10-11 March 1950, survey I. Positions 



of the stations are shown in Fig. 1 . 



(b) The offshore or oceanic water with a high temperature, usually > 18 C, high salinity 

 > 35-20 % and a well-developed convection layer. 



It is evident that mixtures of these waters occur, as was found in the vicinity of Walvis Bay, but 

 generally they are found sharply distinguished from one another with a pronounced boundary. 



There is also evidence of considerable surface heating having affected the coastal waters on survey I, 

 and along with the lack of evidence of active upwelling, this suggests that the conditions throughout 

 the area represent a quiescent state subsequent to previous upwelling. 



