THE HUBBARD GLACIER, ALASKA 295 



the best-known glaciers in Switzerland, and the length of the upper 

 parts of the three longest tongues is entirely unknown and the longest 

 may exceed forty miles. No one of the tributaries as yet bears a name. 



The Upper Glacier 



The main glacier flows southward from the unexplored central part 

 of the St. Elias Range past Mount Hubbard (Fig. 2), a beautiful 16,- 

 400-foot peak named, like the glacier, for Gardiner G. Hubbard, former 

 president of the National Geographic Society of Washington. North 

 of Mount Seattle the Hubbard Glacier has a width of three and one half 

 miles and receives a tributary nearly two miles wide which rises twelve 

 miles back on the slopes of Mt. Hubbard. 



Another great tributary from the east, as wide as the main glacier, 

 has its confluence just to the southward. These three ice tongues 

 form the main upper glacier. It is near this confluence that civilized 

 man has made his farthermost traverse upon the Hubbard Glacier. 

 Several intrepid prospectors advanced this far up an adjacent glacier 

 highway and over a snow divide to the Upper Hubbard Glacier during 

 the gold rushes of 1898 and 1899. 



The Lower Glacier 



Below this confluence, the Hubbard Glacier is crevassed and entirely 

 impassable, and moves down its valley imperceptibly, like the hour hand 

 of a watch, in its irresistible progress to the sea. It descends south- 

 westward over a broad step near the steeply-cascading glacier, shown on 

 the map and in the photographs (Figs. 3 and 4), where it is joined 

 by its longest tributary, the northwest arm. This tributary, two miles 

 wide and at least twelve and one half and probably over twenty miles 

 in length, rises on the slopes of Mt. Vancouver and joins the main 

 glacier at right angles. The combined glacier, with a width of over 

 four miles, advances into Disenchantment Bay in a sinuous cliff four 

 and one half to five miles long and 250 to 300 feet high, one of the 

 most magnificent in the world. Upon this lower glacier surface the 

 Aletsch Glacier, the Rhone Glacier and the Mer de Glace of Switzer- 

 land might be placed without covering over two thirds of the lower 

 Hubbard ice tongue. 



The surface of the Hubbard Glacier is traversed by several prom- 

 inent medial moraines. One of these comes from the northwest tribu- 

 tary and sweeps in a broad curve to the ice front. Another comes 

 from near the west side of the main glacier. The east side of the 

 Hubbard ice cliff is dark and debris-laden (Fig. 5) because this side of 

 the glacier is covered with lateral moraine. The basal layers are filled 

 with dirt and stones (Fig. 6) which perform the work of ice erosion. 

 To the eastward this nearly stagnant border almost joins the entirely 



