80 DISCOVERY REPORTS 



nearly as far north as the southern subtropical convergence it is the layer of richest 

 phosphate content. The maximum south of this convergence is of the order of 1 40-1 50 mg. 

 and is situated in the upper layers of the warm deep water in Antarctic zone stations, 

 sinking to about 1 000 m. in the sub-Antarctic zone ; in the neighbourhood of the subtropical 

 convergence (St. 671) it is found in the mixed water between the north-going Antarctic 

 intermediate current and the south-going warm deep water. In this section phosphate 

 is a maximum in the region 38°-43° S, whilst, north of 35 S, the latitude of the Rio 



LATITUDE 60S 



I 

 STATION F, 





56° 

 22 tocu 



o 

 5 



170- 



O 150- 



ID 



2 



130- 



170-1 



5 6° 



rn 



1" 



ntnn 



5 , 4 

 n 





/' 2 

 r- ^t ld 



m co en 

 OSS 

 I I I 



n 



50°S 

 to 



L 



P ? S AT DEPTH OF MAXIMUM TEMPERATURE 



OF WARM DEEP WATER 



-X 



^5 



"\ 



O 



150- 



130- 



F|0 S AT DEPTH OF MAXIMUM 



SALINITY OF WARM DEEP WATER 



© APRIL 1934 

 ■X OCTOBER 1934 

 ■ JANUARY 1935 



^T-- - -X- " 



--^T- 



Fig. 22. Graph showing the variation of the phosphate content from south to north at the depths of maximum 

 temperature and salinity of the warm deep water in the Scotia Sea, north of the South Orkney Islands. 



Grande ridge, the warm deep water contains less phosphate than the intermediate 

 current, and the maximum of the warm deep water is only 80-100 mg. compared with 

 120-140 mg. in the Antarctic intermediate current. 



In Plate V we have a good picture of the phosphate distribution along section 3 in 

 the eastern part of the South Atlantic Ocean between 69 S and 3 N (Sts. 1154-1184). 



