IV-16 



Along the west coast of North America the eastward-flowing warm 

 current of the Pacific Ocean (the North Pacific Current) splits at 

 about the latitude of the United States-Canadian border; the portion 

 moving south is called the California Current, while that moving 

 north Into the Gulf of Alaska is called the Alaska Current. 



The California Current exerts a moderating effect on contiental 

 temperatures as it moves southward; the major effect, however, occurs 

 during the spring and early summer when the winds are such that in 

 some places the California Current moves away from the coast and 

 cold, nutrient-laden deep water comes to the surfare near the shore. 

 Two major zones of this "upwelling" are off Santa Barbara and off 

 Cape Mendocino, near the northern part of California. During other 

 seasons a complex series of eddies and countercurrents develops, all 

 of which tends to make the nearshore areas very productive. 



The Alaska Current exerts a warming effect on the southern part of 

 Alaska, similar to that of the Gulf Stream in northern Europe. The 

 Bering Sea, which receives some water from the Pacific Subarctic 

 Current, is the birthplace of the cold deep currents of the Northern 

 Pacific, and the waters within the Bering Sea are very cold and rich 

 in nutrients. 



None of the effects of continental shelf and ocean current structure 

 are clearly visible and dramatic. They are a matter of slight dif- 

 ferences in degrees of temperature, of concentrations of certain 



