2. Salinity 



The salinity profile for Atlca Bay is similar to that of temperature, 

 the isolines followj-ng a horizontal pattern between stations in the 

 upper 65 meters and then gradually bending to conform to the contour 

 of the continental shelf and slope. Actual values were ordinary, no 

 highly saline water appearing at the time of sampling. The minimum 

 value of 33.78 °/o° w^s observed at the surface while the maximum 

 salinity (3i;.56 °Ao) was found at a depth of 800 meters. At Admiral 

 Byrd Bay, the salinity of the water increased from the surface to 800 

 meters, and isohaline conditions existed below that depth. A minimum 

 salinity of 33»39 V^o was observed at the surface and a maximum 

 salinity of 3U.67 °/oo was found from 8OO meters to the bottom (2,250 

 meters). 



3. Density 



The density profiles for Atka Bay also are similar to the salinity 

 and temperature profiles in the configuration of the isolines. A 

 minimum density of 27.17 was observed at the surface and the maximum 

 density of 27.83 at 8OO meters. In Adjniral Byrd Bay density of the 

 water increased from a minim\im of 26.88 at the surface to 27.50 at 

 1,000 meters and belov/ that depth decreased only slightly. 



Ii. Sound Velocity 



In Atka Bay the sotmd velocity profile in the surface layer, to 

 a depth of 50 meters, was similar at stations 11 and 12, a slight 

 increase in soiind velocity with increasing depth being noted at both 

 stations. At the inshore station (H), over the continental shelf, a 

 marked decrease in sound velocity occurred between 50 meters depth and 

 the bottom at 65 meters. The minimum sound velocity was U,722 ft./sec. 

 at the bottom. At station 12, sound velocity continued to increase 

 \intil a maximum velocity of U,767 ft./sec. was reached at the bottom 

 depth of 800 meters. The acoustic properties, depicted in the sound 

 velocity profile, agree favorably with the thennal characteristics of 

 the water shown in the vertical temperature profile, where ixesrly^ iso- 

 thermal, conditions were found in the surface layer to a deptti of 50 

 meters throughout the area. A steep negative gradient was found below 

 the surface layer to the shallot^- bottom over the continental shelf, 

 and a relatively weak negative temperature gradient V7as found below 

 the surface layer to the bottom over the continental slope. With the 

 exception of the steep temperature gradient near the bottom at sta- 

 tion H, the pressure effect is dominant in determining the soujid 

 velocity. In Admiral Byrd Bay, sound velocity increosed from the 

 surface to the bottom, the maxiiiium velocity of U,882 ft./sec. occurring 

 near the bottom. The rate of increase was similar to that found in the 



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