ICE SHEETS AND GLACIERS 



a large portion of inner Granite Harbor. Much larger 

 examples are known to the north of MacMurdo Sound ; 

 i.e. Drygalski in latitude 75° S. and the enormous 

 tongues explored by Mawson's expedition near the 

 Antarctic Circle (66'' S.). (See L, Figure 19.) 



The chief dimensions, etc., of some of these Tongues 

 are given in the table following : 



The Ross Island Tongue 



Early in 191 1 this tongue was about six miles long 

 and from one to one and a half miles wide (see J, 

 Figure 19). For a large part It was about one hundred 

 feet above the sea, but this elevation varied consider- 

 ably, for the surface is by no means level, but consists 

 of a series of regular undulations running across the 

 main axis. The difference in height between the top 

 and bottom of these undulations may be as much as 

 fifty feet. The sides are also as a rule lower than the 

 central axis, and where a furrow reached the side it 

 might be only fifteen or twenty feet above the sea-ice. 



The surface of the tongue consisted chiefly of solid 

 ice with comparatively few crevasses on the south side 



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