IIO ALASKA GLACIERS 



The general drift of the suggestion may be illustrated 

 by considering some of the more evident consequences of 

 an assumed change in the temperature of the water of the 

 Gulf of Alaska. Let us assume that the water becomes 

 warmer, and that all other factors affecting glaciation 

 remain unchanged. The consequences would include: 



1. A higher temperature for the air currents flowing 

 from the gulf to the land. 



2. A greater contrast in temperature between the coastal 

 belt and the interior of Alaska, especially in winter. 



3. Greater evaporation from the ocean and a higher 

 humidity for the landward-flowing air resulting from i. 



4. Greater precipitation on the mountains, especially in 

 winter resulting from 2 and 3. 



5. A shorter annual period in which precipitation takes 

 the form of snow resulting from i. 



6. A (probably) lower ratio of snow to rain resulting 

 from 5, qualified by 4. 



7. A higher snow-line. 



8. More rapid waste of ice and snow by evaporation 

 and melting resulting from i, 5 and 7. 



Of these consequences, the increase of precipitation 

 would tend to enlarge glaciers, while the lessened ratio of 

 snow precipitation and the enhanced wasting would tend 

 to reduce them. 



Evidently a lowering of the temperature of the gulf 

 water would be followed by the reverse consequences. 



If the hypothetic rise of ocean temperature were carried 

 to an extreme, the snow-line would be driven above the 

 mountain tops and the glaciers would disappear. If the 

 hypothetic fall of ocean temperature were carried to an 

 extreme, so as to abolish the contrast between sea and 

 land temperatures, the southern coast of Alaska would be 

 reduced to the condition of the western coast, and glaciers 

 would disappear from all but the highest mountains. 



