9. The Bottom Waters of the Ocean 

 and Their Movements 



J-jaymen are likely to consider the water in great ocean 

 depths uninteresting. Measurements prove that it is 

 of almost uniform and constant temperature, a few 

 degrees centigrade above zero, and of a salinity very 

 near 35%c. It is never stirred by ordinary waves and, 

 as far as we know, very little by currents — a changeless 

 sea inhabited only by a sparse and highly curious- 

 looking deep-sea fauna. Apart from that, the bottom 

 water may well appear devoid of interest. 



The view that what we are profoundly ignorant of is 

 unimportant is not always justified. Modern deep-sea 

 research has had excellent reasons to abandon such a 

 negative attitude and devote considerable attention to 

 the very deepest water layers. The reason is that the 

 contact between the water and the underlying sedi- 

 ment is the seat of a physicochemical activity which 

 profoundly affects both media. We know that an inter- 

 change of substance occurs across this boundary. 

 Sediment particles from above come to rest on the 

 bottom, and certain components of this sediment are 



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