" A" TRACKS 



SS'-W 



50»V/ 



45'W 



Figure l.— The scene of the principal activities of the International Ice Patrol. Tracks A, B, and C 

 are routes to and from United States ports. Tracks D, E, and F are routes to and from Canadian 

 ports. Areas 1, 2, and 3 make up the "melting area" described in the chapter on oceanography. 

 Fully 90 per cent of the icebergs that drift south of the 48th parallel each year disintegrate in this 

 "melting area" covering in all some 74,000 square sea miles. The triangle "T" is a very critical area 

 and must be frequently searched out for ice by the patrol vessels themselves 



