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THE NATIONAL GEOGRAPHIC MAGAZINE 



On the other hand, every glacier that 

 reaches the sea presents just such an 

 ice wall. There are scores of such gla- 

 ciers on the Alaskan coast, and probably 

 "hundreds on Greenland, Grant Land, and 

 Spitzbergen, whose fronts extend out 

 into the sea, even into water so deep that 

 they must be afloat, as is much of the 

 barrier. 



The snow which falls upon the surface 

 of this ice field could not possibly supply 

 the waste from the barrier, and another 

 source of supply must be found. This 

 supply is in the numerous and large 

 stream glaciers which bring down the ice 

 from the highlands on the east, west, and 

 south of the bay. The area thus drained 



must be enormous — amply sufficient to 

 maintain the supply. 



The fact that this great ice field is 

 moving northward at the rate of about 

 one-third of a mile a year, as ascertained 

 by Shackleton, would seem in itself as a 

 conclusive demonstration that it is a gla- 

 cier. Sea-ice, unless driven by wind or 

 currents, is quiescent, while the glacier 

 always moves toward lower levels. 



Thus Shackleton glacier is a great 

 mother glacier, into which drains the 

 snow and ice from enormous areas of 

 highland. This glacier collects the ice 

 and transports it northward to the Great 

 Ice Barrier, where it is dropped as bergs 

 into Ross Sea. 



Photo from Capt. Robert F. Scott, R. N. 



FRONT OF THF GREAT ICF BARRIER 



