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DISCOVERY REPORTS 



of deep water. One part of this deep water comes from more northerly latitudes, while 

 another part belongs to the lower vertical circulation of the Antarctic. 



The north-south and vertical components of this complicated circulation are shown 

 schematically in Fig. 23. When studying this figure it must be remembered that the 

 components of the currents at right angles to the paper (away from the reader) are much 

 greater than any of the north-south or vertical components. 



Our conception of the character of the circulation deviates considerably from that 

 commonly accepted. Merz and Wiist (1928) consider the relatively warm and saline 

 water at intermediate depth in high latitudes in the South Atlantic as the last traces of 

 Atlantic deep water, which in these regions approaches the surface. Clowes (1933) has, 



A.C. 



Sub antarcTic water,' 

 ) 





Antarctic water 



Fig. 23. Schematic representation of the north-south circulations within the 

 Antarctic circumpolar current. 



however, shown that this water is of Pacific origin, and according to our view it belongs 

 to the transversal circulation within the Antarctic Zone. It is true that the deep water 

 also moves south and ascends in high southerly latitudes, but traces of the Atlantic deep 

 water are not found in the South Georgia region but much farther to the east, since the 

 easterly flow of the water is considerable. In the Bouvet region the admixture of water 

 from lower latitudes leads to an increase of the sahnity within the intermediate return 

 current. 



The conceptions of Merz and Wiist have been accepted by biologists who have studied 

 the conditions in Antarctic waters. Ruud (1932), for instance, states that the oxygen of 

 the relatively warm and saline layer is low, and says that " these water masses were last in 

 contact with the atmosphere somewhere north of the Sargasso Sea, so a very long time 

 has elapsed since they were aerated ". He says, furthermore, "that the surface layer (of 



