83 



Taldng up the sequence again, we find that the water particles in 

 the mixed zone, because of their greater specific gravity, continually 

 tend to sink, but, due to the effect of earth rotation, actual movement 

 is relegated to a lateral path more or less at right angles to the 

 gradient. This, in brief, is the theory of marine currents in the 

 region with which we deal. 



The particular path an ocean current will follow, therefore, can be 

 foretold provided the geogi-aphical position of dissimilar charactered 

 water be known. The general distribution of coastal and oceanic 

 areas, moreover, is governed to a great degree by the topography 



5j SX- SI So 4? n ^7 4t 4i- 44 



Fig. 43. — Set III. The distribution of cold and warm water at the 50-meter level, May 10-18, 1927 



of the sea basin, and even where the depths are comparatively great 

 we find their reflection in the physical character of the overlying 

 masses. In this connection it will be observed that the Grand 

 Banks after stretching out in a southeasterly direction from the 

 Tail suffers considerable embayment near the forty-fourth parallel. 

 Warm salty water is usually found filling this submarine valley, 

 and near its head, which is close to the 100-fathom curve, we should 

 expect to find the transition zone of the water and consequently the 

 boundary between the currents. 



The position of the cold and the warm water around the Grand 

 Bank May 10 to 18 is shown on Figure 43. The two most interest- 



