ANTARCTIC ADVENTURE AND RESEARCH 



lies less than fifty miles from the coast, or at any rate 

 from the edge of the ice cap. But in the three localities 

 mapped, off Queen Mary Land, off Adelie Land, and 

 in the Ross Sea, these shallow soundings extend much 

 farther out to sea. Furthermore, in all three cases 

 there is deeper water separating a more or less wide 

 submarine ridge from the coastal shelf. Off Queen 

 Mary Land this ridge is three hundred miles long and 

 thirty miles wide. A similar structure with similar 

 dimensions lies off the coast of Adelie Land. A large 

 part of the Ross Sea is unusually shallow for southern 

 waters. Here a large submerged plateau or bank 500 

 miles by 140 miles extends from Cape Adare to Edward 

 VH Land, with several knobs on its surface which 

 approach within some 250 meters of the surface. I 

 have ventured to name these interesting land- forms 

 after Captain J. K. Davis, Sir Douglas Mawson, and 

 Commander Harry Pennell, R.N. The latter com- 

 manded the 'Terra Nova" on her Antarctic voyages, 

 carried out much oceanographic work in the Ross Sea, 

 and died in command of his ship early in the World 

 War. 



The reason for this condition of the sea floor is not 

 obvious. Possibly these shallow areas, which roughly 

 fringe the continent, are of the nature of vast terminal 

 moraines, deposited when the great ice sheet extended 

 from one to three hundred miles farther from the 

 Pole. It is rather a coincidence that the largest ice 

 shelf and the largest glacier tongues are associated with 

 these abnormally shallow seas. Thus off Queen Mary 

 Land is the Shackleton Ice Shelf, which ends in an ice. 



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