In Figure 3, it will be noted that surface salinity values appreciably de- 

 creased from 1 10° to 78° E. longitude along the 32° S . parallel . Values were 

 higher near the Australian coast and decreased as the mid-Indian Ocean area 

 was approached. They were all well above 35,00%fland at the easterly portion 

 exceeded 36.00%p. In November 1959, DIAMANTINA reported almost com- 

 pletely uniform salinities at the surface of the order of magnitude of 35.86%o, 

 along this parallel from 1 10° to 95° E. longitude (C .S . I .R .O ., 1962). Isohalines 

 were generally parallel with the surface, and salinity values decreased with 

 depth to the 800 to 1000 meters level . At this stratum, a region of low salinity 

 was encountered which extended some 300 meters downward. The position of 

 this mass of low salinity water was at a somewhat higher level at the eastern end 

 of the profile. This mass probably represented Antarctic intermediate water from 

 the south. Below the layer of low salinity, values increased towards the bottom. 

 The region of low salinity also showed up in DIAMANTINA's data for the same 

 area . 



Vertical distribution of salinity is shown in Figure 20 for stations 1, 3, and 

 5. Here, in each case the salinity curve rather closely followed the temperature 

 curve. The high salinity water to the east in the zone of turbulence and the 

 intermediate layer of low salinity at 1000 meters are prominent. 



Figure 9 represents a profile of salinity values from station 5 to station 27, 

 or from 32° S . to 4° N. latitude along the 78° E. meridian. The most striking 

 feature of this figure is the large mass of Antarctic Intermediate water of low 

 salinity which pushed its way up from the south at depth and extends as far north 

 as 10° S . latitude. It was probably this mass of water which caused the disturb- 

 ance between 10° and 18° S. latitude. Water with a salinity of 35.00%aOr 

 higher, which it is presumed, originated in the Arabian Sea area, can be seen 

 to the right in the figure. This water extended in general from around 900 meters 

 upwards to the zone of turbulence. A pocket of high salinity water was found 

 just below the zone of turbulence between 11° S . and 2° N . Between 10°S. 

 and 17° S. the low sal'nity, Antarctic Intermediate water, having a lower 

 density, pushed the northern high salinity water closer to the surface and formed 

 an upwelling or divergence. This upwelling is also evident in Figure 11, which 

 shows the distribution of dissolved oxygen. There the Antarctic Intermediate 

 water has a higher oxygen content than the Indian Ocean water. South of 19°S . 

 somewhat higher salinities prevailed at the surface and throughout the zone of 

 turbulence . 



The vertical distribution of salinity at selected stations along the 78° E . 

 meridian is shown in Figures 20,21, and 22. As far north as station 8, (Fig.20D), 

 salinity follows the temperature curve fairly closely, but at station 11, (Fig.2lA), 

 there is a sharp Increase in salinity values below the zone of turbulence. Below 

 800 meters depth there was little change in salinity to the bottom of the cast. At 



33 



