ANTARCTIC ADVENTURE AND RESEARCH 



Ocean, from Mauritius to the Gaussberg (approxi- 

 mately along longitude 80° E. ), which I reproduce in 

 the adjoining figure. There is seen to be a massive 

 intermediate layer of warm water from the tropics, 

 which separates cold layers above and below both flow- 

 ing from the Antarctic to the equator. There is an 

 upper cold layer (of temperature —1.8° C.) about 

 four hundred meters thick which gradually sinks below 

 the warm surface waters to the north of 55° S. latitude 

 to a depth of one thousand meters. Then, below this 

 is a layer of tropical water possibly some two or three 

 degrees warmer which is about 1,200 meters thick. 

 Then below this again, reaching to the bottom, 4,000 to 

 5,000 meters, is a mass of somewhat colder "bottom 

 water" due to a mixing of the very cold upper layer 

 with the tropical water. It is slowly making its way 

 toward the equator. The warm layer reaches to the 

 shoulder of the continental shelf, but does not touch the 

 icy walls of the ice-cap some fifty or one hundred miles 

 farther south. Its salinity is considerably higher than 

 that of the cold layers. There is a thin indefinite layer 

 of surface water, which differs from place to place in 

 regard to temperature and salinity. It is derived in 

 part from the melting of pack ice and icebergs. 



The dominant winds play a great part in the direc- 

 tion of the upper layers of water. Around the Ant- 

 arctic these blow fairly steadily from east to west. 

 The Ferrel Effect also tends to deviate the currents to 

 the left. Hence this cool surface layer about two hun- 

 dred meters deep tends to hold the drift ice together, 

 and to keep it near the continent. As regards deep sea 



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