temperature, while in the deep-water layers of the World Ocean, only salinity is determinant. The 

 Central Arctic Basin is exceptional in this respect; here the maximum observed temperature is 

 +2. 68° and, consequently, even the density of the surface waters is almost exclusively a function of 

 salinity. 



UJ 



Of 



H 

 < 



UJ 



u. 



024680246 



02468024 



4%o 



6%o 



SALINITY 



Figure 1. Graph for computing natural specific volume by temperature 

 and salinity (TS diagram) . 



The density of the water increases with an increase in pressure. Thus, the density of water, 

 whose salinity is 35 o/oo and temperature 0°, is 1. 02813 at the ocean surface, while it rises to 

 1. 07105 at a depth of 10, 000 m under the pressure of the higher-lying layers. Thus, the compres- 

 sibility of water is not very great. However, if water were absolutely incompressible, the ocean 

 level would rise 30 m. 



At great ocean depths an adiabatic increase in water temperatures occurs simultaneously with 

 compression. Thus, the temperature of water sinking from the ocean surface to a depth of 10, 000 

 m rises 1.37°. 



LITERATURE: 48, 62, 73, 75, 154, 157. 



Section 5. The Temperature of Maximum Density 

 and the Freezing Point 



The temperature of maximum density for distilled water is 4°. With an increase in the salin- 

 ity of sea water, this temperature decreases. 



Table 1 shows the temperature of maximum density, the freezing point and the natural densi- 

 ties of sea water at these temperatures. 



12 



