136 MARION EXPEDITIOX TO DAVIS STRAIT AND BAFFIN BAY 



frequently shifting winds are masked by the simultaneous movements 

 imparted by the much steadier and more enduring; slope current. 

 The berg may be likened to a chip floating down a swift-running 

 river with small eddies carrying the object in revolutions, or other 

 tortuous paths, the while it progresses downstream. 



An opportunity to compare the variations in drift due to the winds 

 frequently becomes available on international ice patrol duty when a 

 group of bergs is encountered at sea. During a period of even mod- 

 erate to fresh wnnds the shoaler berg will drift about 14° to the right 

 of the heavier ones in 24 hours and leave the latter some 4 miles 

 astern, the bergs altei-nately separating and congregating with the 

 play of the winds. 



THE GENERAL DRIFT AND FATE OF ICEBERGS IN THE WESTERN 



NORTH ATLANTIC 



The general drift of the icebergs, once they have left the Arctic 

 fjords and reach open water, is governed chiefly by the general direc- 

 tion and rate of flow of the ocean currents. Pack ice in heavy floes 

 driven for days with tremendous force by gales must tend to sweep 

 many bergs into regions Avhieh they might not otherwise enter, leav- 

 ing drift tiacks not conforming to the average. Many bergs may also 

 be detained by the contours of Baffin Bay and Davis Strait, such 

 as shoals, capes, and off-lying skerries. Belts or bands in the cur- 

 rents sort out the bergs; if a berg be in one of these it is assured 

 rapid transportation, while another berg within plain view may float 

 in dead water. The Gateway to the Atlantic, off the Tail of the 

 Grand Bank, marks the major turning point in the iceberg journey, 

 because, no longer guided by the continental slope of North America, 

 the ice is borne directly into the easterly moving masses of the Gulf 

 Stream. The variations in the drifts of icebergs are many; two de- 

 tached from the same glacier on the same day maj' be separated by 

 one or two years in their Atlantic arrival. The length of their total 

 pathway, 1,500 to 1.800 miles, and the average velocity of the cur- 

 rent, 10 to 12 miles per day, suggests that a berg meeting no hin- 

 drances completes the journey in four or five months. As a matter 

 of fact, this can not often happen and the usual history is to be re- 

 leased from the fjords in the summer, to reach the region of Hud- 

 son Strait in autumn, to *' winter " there, and to appear off New- 

 foundland the following spring. A berg calved from its glacier 

 during the winter might be released from the fjord in June and 

 spend the summer drifting out to sea, winter in Melville Bay. be 

 released there in the following summer, reach Cape Dier by that 

 October, and arrive south of Newfoundland with the main body of 

 bergs the next May. The sorting of this kind to which the bergs 

 and other flotsam are subjected in the far north is well illustrated 

 by compai-ing the drift of the Polaris floe party with that of the 

 British steamer Fox. In seven months the foi-mer drifted directly 

 down through Baffin Bay and Davis Strait, making a southing of 

 approximately 1,740 miles, averaging 9 miles per day; while in 1 

 eight months the Fod\ also drifting helplessly in Baffin Bay, made!' 

 less than one-third that direct distance (510 miles), averaging only 

 2 miles per day. The Fo,i\ however, was carried on a very ser{)entine 

 track that really amounted to 1,194 miles. 



