ANTARCTIC ADVENTURE AND RESEARCH 



form is present in the empty main valley below the 

 Taylor Glacier. Blue Glacier (see K, Figure 19) to 

 some extent expands on entering the sea. 



Ice tongues need little description. They may be 

 simple or end in several "tonguelets," or may be asym- 

 metrical as at the snout of the Ferrar Glacier (see K, 

 Figure 19). 



Piedmont Ice. — Broad areas of ice at low level 

 usually fed by one or two valley glaciers. Their 

 crevasses are generally along the long axis of the ice 

 sheet. Sometimes (as in Bowers Piedmont) they are 

 relatively stagnant, without supply from glaciers. 



Confluent Ice. — Ice sheets due to the confluence of 

 several ice tongues but held together by a land barrier 

 (see L, Figure 19). They are not common. 



Shelf ice or ice shelf is a broad sheet of ice due 

 to extensions of land ice, with or without interstitial 

 sea-ice; or it may be due to the accumulation of snow 

 upon old sea-ice. In Figure 19, at M, is shown an early 

 stage of the composite type (with land- and sea-ice). 

 At N is a later stage when snow has obliterated the 

 difference in levels. At O is an example which has col- 

 lected mainly upon banks or low islands. 



The Great Outlet Glaciers 



In my sledge journeys during the summers of 191 1 

 and 1912 I investigated the characteristics of four 

 outlet glaciers, each of which presented features of 

 special interest. Thus the Mackay Glacier was un- 

 usually broad, and flowed through an ''archipelago" of 

 nunataks and nunakols. It reached the sea by several 



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