From these profiles, two distinct water layers in the Antarctic region are 
apparent: Antarctic Upper Water above 200 meters, and Antarctic Deep Water 
which extends to the bottom. Within the Antarctic Upper Water, Antarctic 
Surface Water and Antarctic Winter Water can be distinguished. Separating these 
two water masses is a transition layer identified by steep positive salinity and density 
gradients. Below the Antarctic Winter Water, a second transition layer exists, as 
defined by the temperature profiles, where a steep positive gradient is found. This 
layer lies between Upper Water and Deep Water . 
Station 27 is located in the Cape Colbeck area (75°31'S, 152°08'W). Surface 
water, with temperatures about -1.55°C and salinities 34.00%,, extended to 25 
meters. Below this, a transition layer occurred to 75 meters, where a minimum 
temperature was observed. From 25 to 75 meters, salinities increased rapidly to 
34.279, and only slightly thereafter to 200 meters. Below 200 meters, a transition 
from Upper to Deep Water occurred, with a sharp positive temperature gradient to 
450 meters. Maximum temperature of 1.45°C was observed about 600 meters. From 
this level to the bottom, temperatures decreased gradually to less than 0.5°C. The 
salinity profile shows a weaker positive gradient between 250 and 500 meters, and a 
maximum salinity of 34.74%, about 800 meters. From 800 meters to the bottom, 
salinity decreased slightly to a value of 34.70%,. The sigma-t profile in the upper 
600 meters closely parallels that for salinity, and below this gradually increases to 
the bottom. Sigma-t values ranged from 27.38 at the surface to 27.86 at about 3,000 
meters. Dissolved oxygen content decreased from greater than 8.00 ml/I at the surface 
to a minimum of 4.00 ml/I at about 600 meters. Below 600 meters, oxygen values 
increased slightly to 4.67 ml/| around 3,000 meters near the bottom. 
Station 49 was occupied in the Amundsen Sea area (70°08'S, 111°30'W). The 
temperature profile shows a surface value of -1.75°C, a decrease to about 10 meters, 
and then a slight increase to -1.65°C at 75 meters. The sharp positive gradient of 
transition occurred between 75 and 250 meters, the lower limit being nearer the surface 
than at station 27 in the Cape Colbeck area. Temperature maximum was 1.68°C at 
400 meters. Below this, the curve follows the same pattern as observed at station 27 
but with temperatures approximately 0.2°C higher to about 2,200 meters. From this 
level, temperatures approached those observed at station 27 and became identical 
near the bottom. Salinities decreased from the surface to 10 meters, where 33.629, 
was observed, and then increased to 34.149, at 50 meters. Between 50 and 100 meters, 
a positive gradient was still evident but to a lesser degree than above and below these 
depths. Maximum salinity of 34.73%, occurred at about 600 meters; below this level 
to the bottom, salinity values were nearly identical at the four selected stations. 
Sigma-t values ranged from 27 .08 at the surface to 27.86 near the bottom. Oxygen 
values were about 7.25 ml/I at surface, increased to 7.30 in the upper 25 meters and 
decreased to a minimum of 4.15 ml/| about 300 meters. Below this, they paralleled 
those observed at station 27. 
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