5. How thick is the ice in the Arctic Ocean? 



The average thickness of the Arctic ice pack is about 9 to 10 feet, 

 although in some areas it is as thick as 65 feet, with pressure ridges ex- 

 tending downward into the ocean as much as 125 feet. 



The atomic submarine NAUTILUS passing beneath the North Pole 

 on August 3, 1958, measured a pressure ridge extending 25 feet down. 

 The depth of the ocean at the North Pole was recorded as 13,410 feet; 

 depths as great as 1 3,776 feet have been recorded near the Pole. 



Ice floes ranging from 7 to 13 feet in thickness have been reported 

 in the Arctic. Icebergs, which are pieces of glacial ice floating in the 

 sea, are many times thicker than sea floes. 



Engel, Leonard and Editors of LIFE 



The Sea, Life Nature Library, Time, Inc., 1961. 

 Soule, Gardner 



The Ocean Adventure, Appieton-Century, 1966. 



293-387 0-68— 2 



