GLACIER BAY 1 7 



To the body of information gathered and published by 

 these investigators l our addition was comparatively unim- 

 portant. The five long days of our stay, though utilized 

 to the utmost and replete with interest, served only for a 

 partial review of the features of the immediate coast. As 

 to the more general aspects of the topography and physical 

 history we verified the work of our predecessors, but we 

 were able to extend it only by bringing down to date the 

 records of changing glacier fronts. 



Except near the mouth, the shores of Glacier Bay are 

 treeless, and large tracts are almost destitute of vegetation. 

 A variety of other facts show that this barrenness is due 

 to the recent occupation of the surface by ice, and the ex- 

 tent of the barren zone measures the amount of modern 

 recession of the glaciers. Another series of phenomena, 

 including vestiges of a forest and remnants of a moraine- 

 delta, show that the epoch of expanded glaciers was pre- 

 ceded by an epoch of contracted glaciers when the ice 

 occupied less space than at present. Thus, from a condi- 

 tion of minimum extent, the glaciers grew to a maximum 

 of brief duration and then wasted away to their present 

 dimensions. Vancouver's narrative seems to show that at 

 the time of his visit to the coast (1794) the ice was near 

 its maximum, and subsequent observations, beginning with 

 those of Muir in 1879, show rapid and nearly continuous 

 retreat. The magnitude of this oscillation is perhaps 

 without parallel in the records of glacial changes within 

 the historic period. During the maximum epoch an ice 

 flood not only filled Glacier Bay for thirty-five or forty 

 miles, but submerged many islands and bordering hills 



1 John Muir, Cruise of the Corwin in the Arctic Ocean, p. 136, 1884; The 

 Mountains of California, pp. 23-24, 1894. H. F. Reid, Nat. Geog. Mag., vol. 

 iv, 1892 ; Sixteenth Ann. Kept. U. S. Geol. Survey, part I, 1896. H. P. Gushing, 

 Am. Geol., October, 1891. G. F. Wright, Am. Jour. Sci., Jan., 1887; The Ice 

 Age in North America ; Man and the Glacial Period. I. C. Russell, Am. Geol., 

 March, 1892. 



