THE HUBBARD GLACIER, ALASKA 



3°5 



Fig. 13. Map of the lower fifth of Hubbard Glacier and adjacent ice tongues 

 (after Gannett, Harriman Expedition, and Rich, U. S. Geol. Survey). The whole Rhone 

 Glacier in Switzerland is drawn in black on exactly the same scale for comparison. 

 The hitherto stagnant Variegated Glacier (on the right) and the Haenke Glacier (on 

 the left) became crevassed and advanced between 1905 and 1906, the front of the 

 latter moving nearly a mile in less than nine months and becoming tidal. In 1909 it 

 once more ended on the land. A slight continuation of the advance of Hubbard Gla- 

 cier would separate Russell Fiord from Disenchantment Bay and the Pacific Ocean. 



(Fig. 14) which would be 33 miles long and 100 square miles in area. 

 Its surface would be higher than the present fiord and would receive 

 icebergs from four or more great glaciers, only one of which is now 

 tidal. What would happen to the stagnant, moraine-veneered terminus 

 of Variegated Glacier is a problem. The glacial lake would drain 

 to the Pacific independently until future retreat of Hubbard Glacier re- 

 sulted in the restoration of the lake to the fiord. 



This renewal of activity by Hubbard Glacier is, therefore, of more 

 than ordinary interest, especially as the advance is one of the type now 

 well proved to be due, not to climatic variation, but to excessive ava- 

 lanching during earthquakes. 



VOL. LXXVI. — 21. 



