THE PACIFIC OCEAN 



103 



Table 9. Temperatures and salinities below 3000 meters in stated regions and intervals of depth 



♦Values probably 0.03 °/oo too low. 



greater than 4000 meters are available. The lowest 

 bottom temperatures are found to the south of the equa- 

 tor at stations 160 and 161 in about latitude 13° and lon- 

 gitude 167°. The values of temperature at these stations 

 are l.°09 and l.°08 at the depths^4444 meters and 5084 

 meters respectively. Between the equator and latitude 

 20°, and in longitude 140° west, the bottom temperatures 

 lie between 1?4 and ITS, but to the north of latitude 20° 

 we find values above 1?5 in the entire region except at 

 two stations off the coast of Japan, where lower temper- 

 atures are found. At two stations--141 and 142--to the 

 northwest of the Hawaiian Islands, temperatures are 

 above 1°6, but other than these exceptions the bottom 

 temperatures appear to be very uniform. 



When discussing the mean temperatures at different 

 depths and within different regions, we pointed out that 

 the temperature increases with depth in some regions. 

 Examining the data from the single stations, we find only 

 four stations at which a decided increase of temperature 

 with depth takes place, namely, stations 37, 135, 142, 

 and 146. 



Table 11 gives the observed temperatures at these 

 stations, the potential temperatures (see p. 32) the sa- 

 linities, and the oxygen content. Station 37 is located off 

 the coast of Central America, and here the increase of 

 temperature with the depth is so considerable that the 

 potential temperature is constant. The decrease of the 

 salinity from 34.65 per mille (34.68) at 2730 meters to 

 34.63 per mille (34.66) at 3231 meters is so small that 

 we cannot give any weight to this difference. We must 

 assume that the salinity is constant, and the constant 

 potential temperature then indicates that indifferent 

 equilibrium exists below a level of 2700 meters. 



Stations 135, 142, and 146 are all taken in nearly the 

 same region. At these stations the temperature in- 

 creases with depth, but the potential temperature de- 

 creases and at the same depth is very nearly the same 

 at the different stations. The salinity, on the other hand, 

 appears to be constant. The variations must be ascribed 

 to accidental errors of observation because, combining 

 observations from five stations in this region, we find 

 the salinities 34.638 f34.668), 34.650 (34.680), and 34.644 

 (34.674) per mille at the depths 3100, 3700, and 4100 

 meters, respectively; that is, practically no variation 

 with depth. The equilibrium must, therefore, be stable. 

 At a few other stations in this same region we find an 

 indication of a temperature minimum at a depth of 3700 

 meters, but the increase below this level is smaller than 

 0?05 and therefore the stratification is still more stable 

 at these stations. Helland-Hansen (1930) has shown that 



Table 10. Bottom temperatures of water, bottom 



depths greater than 3000 meters, 



Pacific Ocean, Carnegie, 1929 



Station 



Lati- 

 tude 



Longi- 

 tude 

 West 



Depth 



Ther- 

 mom- 

 eter 



Bot- 

 tom 



Tem- 

 per - 



ture 



in the eastern North Atlantic the potential temperature 

 is constant below a level of 4000 meters, whereas in the 

 western North Atlantic it decreases toward the bottom. 



