ANTARCTIC SURFACE WATER 



3i 



eastwards across the South Pacific Ocean is modified by the addition of less saline and 

 poorly oxygenated water from the north, which may have the effect of reducing the 

 silicate content of the layer towards the east. 



Close to 8o° W the silicate content of the surface water varies very considerably with 

 the time of year. It must also be remarked that there is a seasonal variation in the latitude 

 of the ice-edge which is not without effect on the silicate content in this region. In 

 1934 the minimum amount was found in September when no phytoplankton activity 

 was apparent and when the ice-edge was farthest north. This minimum in September 



LONGITUDE 

 STATION n n 



BO W 



100" 



I 



140" 



160 W 



120" 



■ m C \SS ' t" 1 5 2 - ?fX "O" ^^ l/ ' ffl ""> - -^ n« 



_n ^ o ^" o*J- <r o ■*- o m oifi trial inin mio <n to ctiid !oid <eu3 a)<n^ 



<*ir\j f\i n c\j p](u ojco (\J n r\j cn(\i (\joj pjw r\jf\j r\j oj ojnj f\J(\J WOJ (uc\jru 



— U 1 1 — 1 u l_i 1 ; 1 u 11 ~i T 1 .7 77 "T 7 ~.~ 77 T 



3000- 



in 



5 

 a 



5 



■ 2000- 



1000- 



O O WESTWARD CRUISE DEC-JAN. 1934 



X X EASTWARD CRUISE FEB - MAR 1934 



Fig. 8. The average silicate contents of the o-ioo m. layer in the westerly and easterly cruises of the ice-edge 

 region in the South Pacific sector of the Southern Ocean. 



is entirely contrary to expectation and also contrary to the o-ioo m. averages for the 

 southern region of the Antarctic zone. The positions and surface values of the various 

 ice-edge stations close to 8o° W are given below . 



The low values of September and November 1934 require further confirmation before 

 any discussion on the seasonal variation in silicate at the ice-edge in this position can 

 be attempted, although in late September 1932 at St. 974 in 63 57' S, 101 16-0' W, 



