Fig 3. Oblique showing a part of an ice island with the dimensions 
about 5.5 x 4 km., drifting from the Lincoln Sea toward the south 
through the Nares Strait. 
The name "ice island" is given to a rare form of tabular berg, 
with a thickness of 30 - 60 m. (about 100-200 ft.), characterized 
by a regularly undulating surface, with ridges and intervening 
troughs, giving them a ribbed appearance from the air. 
They originate chiefly from ice shelves in northern Ellesmere 
Island and northern Greenland. Some few large islands are drifting 
in the Arctic Ocean (commonly used as drifting ice stations for the 
purpose of scientific research), and a number of smaller ones have 
found their way into the channels of the Canadian Arctic Archipelago. 
(Photo: Ragnar Thorén, on August 5, 1963, altitude about 460 m. or 
1,500 ft., see PICTURE ATLAS OF THE ARCTIC, Fig 48.)