530 A. M. BATEMAN KENNECOTT GLACIER OE ALASKA 



precipitation. These data at the town of Kennecott (elevation, 2,003 



feet), are: 5 



Mean Temperature 



May 



June 



July 



Aug. Sept. 



Oct. 



Nov. Dec. Annual 



42.3 



51.8 



51.4 



52.8 46.0 



28.3 



6.4 21.4 27.3 



40.0 



51.4 



56.8 



51.0 47.8 



30.9 



19.2 9.5 29.6 



1917 Jan. Feb. March April 



1917 7.6 12.6 21.8 28.4 



1918 5.2 6.0 9.4 28.2 



Precipitation (Incites) 



1919 1.03 0.15 0.18 tr. 1.44 tr. 2.30 0.20 2.00 1.07 1.04 1.55 10.96 



The elevation above sealevel of the recording station is approximately 

 the same as the top of the glacier near this point. Some climatological 

 records have been kept at the mines, about 4,000 feet above the town of 

 Kennecott, but are too scattered to be of valne. 



This is the climatic setting of Kennecott Glacier, in the "Wrangell 

 Mountains. 



Still farther inland beyond the Wrangell Mountains the precipitation 

 becomes less and equals that of the semiarid and arid regions of south- 

 western United States. An annual precipitation as low as 7.76 inches 

 has been recorded at Fairbanks. 6 The summers are short and warm 

 and the winters extremely cold. Glaciers do not exist and the region 

 never has been glaciated, except for local small ice-tongues. 



In comparing various Alaskan glaciers, particularly with respect to 

 their rate of movement, this climatic difference must be taken into con- 

 sideration. Differences of precipitation and temperature, and relative 

 durations of summer and winter seasons would be expected to affect the 

 rate of movement of glaciers. In comparing Alaskan glaciers with 

 those of other regions, such as the Alps, other climatic factors also enter. 

 Kennecott Glacier is situated in a latitude where sunlight in early sum- 

 mer persists for more than twenty hours of the day ; but the sun's rays 

 are more slanting and consequently less warm. The summer season is 

 shorter and the mean annual temperature much lower; the duration of 

 time when the air temperature is above 32° Fahrenheit is, therefore, 

 much less. 



Description of Glacier 

 type 



Kennecott Glacier is of the valley type (see figure 3). Two large 

 branches, an eastern one, from Mount Regal, and a western one, from 

 Mount Blackburn, coalesce about 6 miles above its terminal and con- 



6 U. S. Geol. Survey Bull. 525, 1913, p. 27. 

 5 Records supplied by U. S. Weather Bureau. 



