1910.] INLAND-ICE OF THE ARCTIC REGIONS. 127 



It is easy to see that Russell's and Reid's views might each apply 

 in special cases dependent: (a) upon the narrowness or the sinuosi- 

 ties of the fjord, which would determine the reach of the waves; 

 (b) upon the steepness of the slope back of the ice cliff, which would 

 regulate the different velocities of surface and bottom layers of ice, 

 and determine the measure of crevassing; (c) upon the irregularities 

 in the floor of the ice tongue, which would largely fix the amount 

 of shearing and overthrusting ; (d) upon the presence or absence of 

 warm ocean currents, which would regulate the rate of melting of 

 the ice by the fjord water; and (e) upon the freezing of the water 

 surface/^^ which must put a bar upon the action of the waves during 

 the colder period. 



Studies of Bergs Bom of the Inland-ice of Greenland. — Though 

 ice bergs are discharged from the inland-ice throughout practically 

 the entire extent of the coast line of Greenland wherever inland- 

 ice reaches the sea, yet the great bergs which push out into the broad 

 Atlantic arise either on the west coast between Disco Bay and 

 Smith Sound, or on the east coast south of the parallel of 68°. To 

 the north of this latitude the bergs are firmly held in the heavy 

 pack-ice, while the bergs of southwest Greenland form for the most 

 part in such narrow fjords that they are too small to travel far be- 

 fore their final dissolution. 



The size of the Greenland ice bergs has probably been much 

 overestimated. Of 87 measurements made by von Drygalski on the 

 large bergs calved in the Great Karajak fjord, the highest reached 

 137 meters above the water, or about 445 feet. This mass of ice 

 was, however, against the glacier front, and probably rested on the 

 bottom. None of the others measured were much above 100 meters 

 high or about 325 feet."^ The berg shown in Fig. 43, photo- 

 graphed by an earlier explorer in Melville Bay, measured 250 feet in 

 height. 



During fourteen months spent in the immediate vicinity of the 

 steep front of the Great Karajak ice tongue, von Drygalski carried 

 out extensive studies upon the calving of bergs, and has distin- 

 guished three classes. Those of the third class form almost con- 



"^ R. S. Tarr, "The Arctic Ice as a Geological Agent," Am. Jour. Sci.. 

 Vol. 3, 1897, p. 224. 



"** E. von Drygalski, " Gronland-Expedition," etc., /. c, pp. 367-404. 



