214 



DISCOVERY REPORTS 



LATI TUDEI 70°S 



2500m 



_3SOOm 



5000 m 



Text-fig. 19. Distribution of temperature (° C.) between 70 S. and 35 S. in the region of the 

 Greenwich Meridian, March-April 1937 (see Text-fig. \a for station positions). 



discontinuity (indicated by the 23 C. isotherm) with the South Atlantic Central Water. The Tropical 

 Convergence does not appear to have as much influence on the distribution of pelagic polychaetes as 

 either the Antarctic or Sub-Tropical Convergences. 



(ii) INTERMEDIATE AND DEEP WATER MASSES 



When the Antarctic Surface Water sinks at the Antarctic Convergence it mixes with water of Sub- 

 Antarctic origin, and together with this gives rise to the north-flowing Antarctic Intermediate Water. 

 Below the Antarctic Surface Water and Antarctic Intermediate Water throughout the South Atlantic 

 is the Warm Deep Water with a southerly component in its movement, and beneath it the heavy 

 Antarctic Bottom Water. 



