VARIATIONS OF GLACIERS 753 
A general description of the glaciation of the Alaska Range has 
been given by Capps’ so far as it is known. The greater develop- 
ment of glaciers on the southern slope of the range, as compared 
with the nothern slope, is ascribed to the greater snowfall and to 
the larger collecting grounds. The southern slope is about twice 
as long as the northern. 
Tarr has reviewed the observations made on Alaskan glaciers 
and their variations. He emphasizes the influence of avalanches 
due to earthquakes in causing spasmodic advance of glaciers.’ 
In association with Martin he has published details of the sudden 
advance of the Yakutat glaciers due to the earthquake of 18993 
(see earlier reports of this series). Grant and Higgins have col- 
lected their observations on the glaciers of Prince William Sound 
and Kenai Peninsula (already mentioned in these reports) in a 
bulletin of the United States Geological Survey, with maps and 
illustrations.4 Several other bulletins of the Geological Survey 
contain maps showing the location of glaciers, but the descriptions 
of the glaciers are very cursory.® 
t Stephen R. Capps, “‘Glaciation of the Alaska Range,” Jour. Geol., XX (1912), 
415-537- 
2 Presidential address before the Association of American Geographers, Science, 
XXXV (1912), 241-258; and Annals of the Assoc. of Amer. Geographers, II (1912), 
I-24. 
3R. S. Tarr and Lawrence Martin, ‘‘The Earthquakes of Yakutat Bay, Alaska, 
in September 1899.”’ U.S. Geol. Survey, Prof. Paper No. 69, chap. iv. 
4 Bull. No. 5206. 
5 F. H. Moffit and Stephen R. Capps, ‘‘ Mineral Resources of the Nizina District, 
Alaska,” Bull. No. 488; Stephen R. Capps, ‘‘The Bonnifield Region, Alaska,” Bull. No. 
501; “The Yentna District, Alaska,” Bull. No. 534; F. H. Moffit, ‘‘Headwater Regions 
of Gulkana and Susitna Rivers, Alaska,’ Bull. No. 498. 
