Cold , ice-beoring 



Mixed 



Fig. 28. The surface currents of the North Atlantic. 

 Siniphfied diagram by A. J. Lee. 



Ridge so that to the north-east of it the warm water is never deeper than 

 the upper level of the Ridge and below this 500 metre level ii cold arctic 

 water, although relatively warm Atlantic water may be found at 2,000 

 metres on the south west side. The ridges between Iceland and Greenland, 

 and between Faroe and Iceland, act as barriers to the flow of cold deep water 

 into the Atlantic and the main outflow of cold water is forced to the surface 

 well to the west as the Greenland current. This continues, by then somewhat 

 mixed with water from west Greenland, as the Labrador Current passing 

 close to Newfoundland and then affecting the Atlantic coast of the United 

 States. It is the warmth of the North Atlantic Drift that keeps the seas of 

 the North European areas ice-free when corresponding latitudes on the 

 western side of the Atlantic are frozen. The Bear Island area, well into the 

 Arctic Circle north of Norway, supports a great winter fishery for cod and is 

 the same latitude as the north of Baffin Island; yet the flow through the Faroe- 

 Shetland Channel is only onc-fifteenth of the Gulf Stream. The St. Lawrence 

 is about the same latitude as the Scilly Islands; west Iceland is ice-free but 

 only 200 miles across the Denmark Strait is frozen Greenland. Why does the 



109 



