116 



MAKIOX EXPEDITION TO DAVIS STRAIT AND BAFFIN BAY 



until equilibrium is reestablished. Then the cycle of destruction is 

 reenacted. 



Bergs which calve frequently, producin<r numerous ^rrowlers, 

 naturally expose a greater and greater ice surface, and therefore 

 waste faster than those bergs which resist fracture because of thcii- 

 particular sliape, or of calmer seas, or of other causes. Bergs which 

 are completely water washed present fewer overhanging prominences 

 than others, and are, therefore, less liable to calve. Such shaped 

 bergs exposed to the same conditions survive longer than any other 

 kind. 



The natural processes of disintegration that attack a Greenland 

 berg when it reaches the warm ocean south of the tail of the (Irand 



An Iceberg Buffeted by Winter Gales 



Figure 75. — Berss drifting south of Newfoundland in early season (February to 

 March) leave pr'otective coast lines far behind. Then they are subjected to a 

 severe buflfeting by gales and ocean swell which sometimes shoot the spray hun- 

 dreds of feet in the air. Only the smaller-sized bergs, however, display any per- 

 ceptible motion ; ice bodies as large as the one shown here remain as immovable 

 as a rocij. This berg measured 150 feet above the water and 400 feet in length. 

 (OflBcial photograph, international ice patrol.) 



Bank are interesting to follow. Thus when one particular berg 

 Avhich on April 4, 1924, emerged from arctic surroundings of 32° F., 

 to enter mixed Avater of 35° F.. was then of medium size, consisting 

 of a low ridge at one end separated l)y a shallow channel from a 

 peak approximately 125 to 150 feet high at the other. The wind 

 remained light for the next two days and the water Avarmed from 

 34° to 38°, while a slight swell washing the base of the berg ma- 

 terially assisted the melting processes. A growler was observed to 

 calve occasionally, but disintegration was not rapid. By the next 

 day the temperature of the sea had risen to 40° F., and a heavy swell 

 making up about noon initiated rapid wastage. When the berg 

 crossed the "cold wall." earlv tlie morning of the 8th, and floated in 



