290 



EARTH FEATURES AND THEIR MEANING 



a thick snow and ice terrace floating upon the sea and rising to 

 heights of more than 150 feet above it (plate 15 Band Fig. 316). 

 The visible portions of this shelf-ice are of stratified compact 



FIG. 316. The shelf ice of Coats Land with the surrounding pack ice showing 

 in the foreground (after Bruce). 



snow, and the areas which have thus far been studied are found 

 in bays from which dislodgment is less easily effected. The origin 

 of the shelf ice is believed to be a sea-ice which because not easily 

 detached at the time of the spring " break-up " is thickened in 

 succeeding seasons chiefly by the deposition of precipitated and 



drifted snow upon its 

 surface, so that it is 

 bowed down under 

 the weight and sunk 

 to greater and greater 

 depths in the water. 

 To some extent, also, 

 it is fed upon its inner 

 margin by overflow 

 of glacier ice from 



FIG. 317. Tidewater cliff at the front of a glacier 

 tongue from which icebergs are born. 



the inland ice masses. 

 Icebergs and snowbergs and the manner of their birth. Green- 

 land reveals in the character of its valleys the marks of a large 

 subsidence of the continent the serpentine inlets or fjords by 



