292 



EARTH FEATURES AND THEIR MEANING 



mass of ice rises out of the water some distance away from the 

 cliff, lifting as it does so a great volume of water which pours off on 

 all sides in thundering cascades and exposes at last a berg of the 

 deepest sapphire blue. The commotion produced in the fjord is 

 prodigious, and a vessel in close proximity is placed in jeopardy. 



Even larger bergs are sometimes seen to separate from the ice 

 cliff, in this case an instant before or simultaneously, with a loud 

 report, but such bergs float away with comparatively little com- 

 motion in the water. 



The icebergs of the south polar region are usually built upon a 

 far grander scale than those of the Arctic regions, and are, further, 

 both distinctly tabular in form and bounded by rectangular out- 

 lines (Fig. 321). Whereas the large bergs of Greenlandic origin 

 are of ice and blue in color, the tabular bergs of Antarctica might 

 better be described as snowbergs, since they are of a blinding white- 



FIG. 320. A northern iceberg surrounded by sea ice. 



ness and their visible portions are either compacted snow or alter- 

 nating thick layers of compact snow and thin ribbons of blue ice, 

 the latter thicker and more abundant toward the base. All such 

 bergs have been derived from the shelf ice and not from the inland 

 ice itself. Blue icebergs which have been derived from the inland 

 ice have been described from the one Antarctic land that has been 

 explored in which that ice descends directly to the sea. 



