ICEBERGS 87 



with the result that their appearance differs considerably in 

 Northern and Southern Hemispheres. 



The Arctic icebergs originate on the \\vst const of (Green- 

 land, where the coast is rugged, precipitous, and characterised 

 by deep glacinated inlets or fiords. These fiords are the birth- 

 place of icebergs, which break away from the terminal portion 

 of the glaciers. According to Rink, there are five principal 

 ice-fiords on the west coast of Greenland between 67^ and 

 73 N. Lat., every one of which receives annually many 

 thousand cubic feet of ice. These fiords are, from south to 

 north Jakobshavn, Torsukatak, Karajak, Kangerlugsuak, 

 Umanak, and Upernavik. Other glaciers which give rise 

 to icebergs are Humboldt Glacier, between Smith Sound 

 and Kennedy Channel, and Petovik Glacier, between 76 

 and 76! N. The largest icebergs are split off from the 

 extremity of glaciers which reach the sea on a gentle 

 slope. 



The splitting off an iceberg from the glacier's extremity is 

 termed " calving." The glacier protrudes seaward until by 

 sea disturbance, by its own weight, or by some other agency, 

 equilibrium is destroyed and the iceberg breaks off. Since 

 many of the fiords are shallow at their seaward extremity, 

 many of the icebergs become stranded on the so-called iceberg 

 banks. The height of Greenland glaciers has frequently been 

 measured. Bergs over 300 feet high are rare in fact, those 

 over 200 feet are noticeably high. There are, however, records 

 up to 800 feet (by the steamer Principello in April, 1915), or 

 even 1,000 feet (steamer Marie, May, 1906). Whether these 

 latter records are based on careful trigonometrical calculations 

 is doubtful, and such heights should only be accepted with 

 reserve. 



According to Steenstrup, the portion of the ice above water 

 bears to that below water a proportion of from i : 7*4 to i : 8*2. 

 As a rule it may be assumed that a tabular iceberg floats with 

 from one-seventh to one-ninth of its bulk above water. 

 Kriimmel gives i ; 8 as one extreme and i : 4 the other, and. 



