168 DISCOVERY REPORTS 



The stations at the inshore end of the Walvis Bay line all show the typical features of the cool 

 coastal waters, with temperatures of less than 13 C. and salinities of less than 35-00 % . The stations 

 at the offshore end of the line, on the other hand, lying in warmer and more saline water, are charac- 

 teristic of oceanic conditions. (It should be noted here that the contouring of the isotherms at 

 WS 1079-81 may be open to question for the observations at WS 1079 were taken before, and those 

 at WS 1080 and 1081 after, a considerable gale. As will be shown later (p. 188) this gale produced 

 a considerable alteration in the position of the surface isotherms, and yet no allowance could well be 

 made for this in the general picture). 



20- 

 S 



, CAPE FRIO 



25- 



30 v 



POINT 



IO E IS 



Fig. 21. The distribution of temperature (° C.) at a depth of 300 m. on survey II, September-October 1950. 



Between the Walvis Bay line and the Mowe Point line the distribution of surface-temperature is 

 exceedingly complex. From the bathythermograph observations and the records from the distant 

 reading thermograph a more detailed construction of the surface isotherms has been set out in Fig. 19. 

 It will be seen that while the cool coastal water (less than 14 C.) continues along the coast as far as 

 Mowe Point, the temperature rises fairly rapidly offshore to an area of relatively high temperature 

 some 60 miles from the coast. Here the temperature is typically oceanic, reaching a recorded maximum 

 of 16-5° C. This area of high temperature, a patch about 60 miles in diameter, is apparently an isolated 

 feature, for on its western boundary the temperature is again lower (15-5° C.) Several interpretations 

 could be made of this distribution, and unfortunately little guidance can be obtained from the sub- 

 surface data, which are only available at the stations. It may be that this phenomenon is solely due 



