VARIATIONS OF GLACIERS 551 



The new Icy Bay at the western border of Malaspina Glacier was mapped 

 in 1913 by A. G. Maddren of the United States Geological Survey. The 

 recession of Guyot Lobe now amounts to nine or ten miles. Maddren's map 

 indicates that the Bering Glacier, which has hitherto been considered a single 

 piedmont ice mass, is really two separate piedmont bulbs (Coast Survey Chart 

 8002, edition of March 12, 191 2). A similar condition at Grand Plateau 

 Glacier was noted from close inshore by the special steamer of the International 

 Geological Congress of 1913. In both cases the earlier mapping was in error, 

 for there has been no recession of either the Grand Plateau Glacier or the Bering 

 Glacier in historical times. 



Copper River Canyon. — The Childs Glacier has retreated slightly and its 

 northern margin, as measured by Caleb Corser, is now 1,500 feet from the rail- 

 way bridge on the Copper River & Northwestern Railway. In spite of an 

 advance of more than 60 feet in the interval, its net change, from June 16, 191 1, 

 to July 12, 1913, was a recession of 26 feet, and from the latter date to Novem- 

 ber 7, 1913, it retreated between 100 and 150 feet more. Allen Glacier, after 

 a slight advance in 1912, began to recede in 1913. Between August 26, 1910, 

 and July 12, 1913, it advanced 2650 feet, or four-tenths of the distance to the 

 railway north of it. From the latter date to October 28, 1913, Corser's 

 measurements show that its northwestern border retreated 300-700 feet. 

 Schwan Glacier is said by a prospector to have advanced in 191 2. 



Wrangell Mountains. — In connection with her successful ascent of Mount 

 Blackburn in 1912,^ Miss Dora Keen made important observations of snow- 

 fall and temperature, giving an idea of the precipitation that supports the large 

 Kennicott Glacier. The total snowfall for thirty- three days (April 22 to 

 May 24) was 40 feet (packed to 20 feet). During this period the temperature 

 at altitudes of from 2,000 to 16,140 feet above sea-level ranged from —6° F. to 

 -+-70° F. At her base camp, altitude 5,500 feet, three feet of snow fell in 

 thirteen consecutive days, while at a camp 6,900 feet higher the snowfall during 

 the same period, which included four days of hot sun, was very much greater. 

 It was measured by the burial of bamboo poles 1 2 feet long in front of a shelter 

 excavated in the snow and may be estimated at 30 feet (packed to 10 feet). 

 At the summit of Mount Blackburn the snowfall seems to be less, though it 

 may be all carried away by the winds. An important part of the alimentation 

 of Kennicott Glacier comes in great snow avalanches from the steep walls of its 

 valley. Some of these avalanches, which are most abundant between noon and 

 4:00 P.M., advance three miles from the valley wall, or the whole width of the 

 glacier. 



Prince William Sound. — -Barry Glacier in Harriman Fiord retreated an 

 amount varying from about 2,500 feet on the western side to at least 7,200 

 feet on the eastern border between Martin's visit in July, 1910, and Johnson's 

 in 1913. Coxe Glacier, formerly a tributary of the Barry is now independent. 



I World's Work, XXVII (1913), 80-101. 



