CHAPTER I 



EXISTING GLACIERS 



GENERAL DISTRIBUTION 



NEARLY all the glaciers of Alaska are comprised within 

 a belt of moderate width which follows the southern coast 

 from the Aleutian Islands to Portland Canal (see fig. i). 

 Curving about the great bight of the Pacific Ocean known 

 as the Gulf of Alaska, this belt has a length of 1,600 miles, 

 and its extreme width, near the middle, is about 250 miles. 

 Within it the arrangement of glaciers is irregular, but their 

 more important groups occupy the middle region, while 

 near the ends they are comparatively sparse and small. 



The explanation of this massing of glaciers along the 

 southern coast is not far to seek. The general circulation 

 of the Pacific Ocean brings to the Gulf of Alaska a cur- 

 rent of water which has been warmed in the tropics and 

 still retains so much heat that its mean temperature is 

 considerably above the normal for the latitude. The 

 ocean is therefore, at most seasons, warmer than the con- 

 tiguous land, and though air currents passing from ocean 

 to land convey heat to the land they are themselves cooled. 



(7) 



