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TEMPERATURE OF THE HYDROSPHERE 187 



and 80° W. long., and in an eastward broadening area in the Span- 

 ish Sea, which nearer the land becomes 9° or more and in the Gulf 

 of Cadiz 11°, thus showing the influence of the undercurrent of 

 warmer Mediterranean waters. At 2,000 meters in the southwestern 

 part of the South Atlantic, the southern part of the Indian, and the 

 whole Pacific, the temperature lies between 2° and 3° C. It rises to 

 something over 3° in the other parts of the Atlantic, except in the 

 southwest part of the Sargasso Sea region and in the Spanish Sea 

 between the tropic of Cancer and Cape Finisterre on the north 

 coast of Spain, where it is something over 4° C. Temperatures 

 above 3° C. are also found at this depth in the two northern exten- 

 sions of the Indian Ocean — the Bay of Bengal and the Arabian Sea, 

 the latter having temperatures as high as 5° or 6° C. 



At 3,000 m. the Pacific has a uniform temperature of 1.6° to 2.2° 

 C, except where depressions surrounded by higher rims occur, as in 

 the Fiji * basin and the Coral basin, where the temperatures rise 

 from 2° to 2."/° C. In the Indian Ocean at this depth great uni- 

 formity of 1.3° to 1.9° C. occurs with but few exceptions, notably 

 beneath the Arabian and Bengal gulfs, where it rises sometimes to 

 2.9° C. In the Atlantic the temperatures are somewhat higher, 

 falling nowhere below 2° C. north of 40° S. lat.. and rising more 

 often to 2.2° or even 2.9° C. Only below the eastern part of the 

 Guinea current, and the Sargasso Sea, are the temperatures more 

 than 3° C, reaching a maximum of 3.7° C. 



At 4,000 meters and lower the temperature of the North Pacific 

 is nearly uniform at 1.6° to 1.7° C, even in depths of 6,000 

 meters. The same temperature occurs in the various depressions 

 southwest of the Hawaiian Islands, except in the deeps, like the 

 Tonga and Kermadec deeps, where temperatures as low as 1.1° C. 

 have been obtained. Near the border of the Antarctic continent the 

 Belgica found temperatures of about 0.6° C, while in the Atlantic- 

 Indian Polar basin, which descends below 5,000 meters, a tempera- 

 ture of 0° to — 0.5° obtains. This cold bottom water flows north- 

 ward in the west Atlantic trough, for in the basins composing it 

 bottom temperatures of 0.1° to 0.4° are found. The mid- Atlantic 

 and the Whale swells, or rises, however, cut off the east Atlantic or 

 South African trough from these cold waters to the south, for, 

 although this descends to depths of 5,000 to 5,600 meters, the lowest 

 bottom temperatures found are -\- 2.2° to + 2.6° C. 



In the Cape trough to the south of the Whale ridge the tempera- 

 ture at 4,800 m. is 0.9° C. This shows that the Whale ridge can- 



* Some lower temperatures occur in this basin also, suggesting that it is not 

 completely closed. 



