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A PROBLEM THAT HANDICAPS THE ICE PATROL 



One of the most important natural problems which has confronted 

 the ice patrol has been the securing of advance information regarding 

 the probable drift of ice after arrival at the gateway to the Atlantic 

 (the vicinity of the Tail of the Grand Bank). If we glance at a general 

 map of the northwestern North Atlantic we may trace the general 

 course followed both by the current and by the ice stream southwards 

 along the continental slope from Baffin Land to the Tail of the Grand 

 Bank without great change in direction for a distance of 1,800 miles. 

 But when the cold Arctic water is discharged past the Tail of the 

 Bank it is no longer preserved by the general trend of the continental 

 slope, but is forced to meet directly the easterly moving masses of, or 

 associated with, the Gulf Stream. It is at this point that the course 

 of the current, and likewise its freight of ice, is subjected to great 

 variations in direction. Naturally it is extremely desirable for the 

 patrol to be able to disseminate to shipping, whether the ice will be 

 deflected northward again into the shallow shelf waters, or whether 

 it will be swept southward across the North Atlantic Lane Routes, 

 and so create a very grave menace to shipping. If the patrol had 

 knowledge of the drift tracks which bergs would follow after arrival 

 at the gateway to the Atlantic, much more detailed information could 

 be furnished to approaching vessels, especially during the protracted 

 periods when fog enshrouds this cold-water region. 



NEW METHODS IN OCEANOGRAPHY INTRODUCED ON ICE PATROL 



The interdepartmental board charged with the administration of 

 ice patrol had for some time been following the modern methods 

 pursued in oceanography, particularly those taught at the Geophys- 

 ical Institute, Bergen, Norway. The board believed that these 

 methods had a practical application to the ice patrol's unique problem, 

 as described in the preceding paragraph. The new thought in this 

 branch of oceanography was more or less widely introduced by Prof. 

 V. Bjerknes and others ^ in a treatise on the dynamics. Since that 

 time several Scandinavian oceanographers have attained such 

 success in further applying Bjerknes' basic formula to oceanographic 

 investigations that arrangements were made for me to attend the 

 Geophysical Institute, Bergen, 1924-25, for a year's study with Prof. 

 Helland-Hansen on the theory of free motion and for instruction in 

 the various methods of illustration. The oceanographic records of 

 the ice patrol, some 3,000 observations of temperature and salinity 

 from various depths and places in the ice regions, were also treated 

 at the Geophysical Institute by mathematical computation. It is 

 hoped to have this research published. The first maps thus ever 



1 Dynamic Meteorology and Hydrography. Carnegie Inst. Pub., Washington, 1910-11. 



