obtained from the Evergreen' 8 oceanograpliic surveys on the east slope 

 of the Grand Banks revealed a well defined Labrador Current flowing 

 with a maximum velocity of 0.6 knots. With such a current system 

 in evidence, bergs could have crossed both tracks C and B. There was 

 a great reduction in the number of bergs between those found in 

 the southwestern part of Baffin Bay during the 1948 ice census and 

 presumed to include those bergs which would appear in the Grand 

 Banks region during the 1949 season, and the actual number found 

 in the 1949 season in the Newfoundland area. Bergs which did 

 arrive in the vicinity of latitude 48° N., were small and eroded, and 

 on an average did not last much over 4 days after arriving in this 

 latitude off the eastern slope of the Grand Banks. Several times in 

 March and April, groups of five or more bergs threatened to drift 

 into this region only to disappear within 5 days of their sighting. 

 Elsewhere in this Bulletin there is a discussion of weather and its 

 possible effect upon the movement and attrition of icebergs during 

 and immediately preceding the 1949 season. 



AmPil ICE RECONNAISSANCE 



As in previous years, two winterized PBlG (flying fortress) air- 

 craft were used for aerial reconnaissance. These two aircraft were 

 the only units used by the ice patrol to scout for ice, except for three 

 flights made in PBY5A aircraft and one occasion on G June when 

 the Evergreen was employed to locate and track a small berg at 

 48°55' N., 51°25' W., at the end of an oceanograpliic cruise. Weather 

 and ice conditions for the spring of 1949 combined to allow the ice 

 patrol season to be completed without ordering the cutters Mocoma 

 and Acushnet to Argentia, Newfoundland, for duty as ice-patrol 

 vessels. Although this season was notably successful in the use of 

 aircraft for searches, it is too much to expect that in future years 

 aircraft alone may accomplish the mission of ice observation and 

 patrol. Radar has proven valuable equipment in these planes, but 

 Avith present radar equipment it is impossible to distinguish between 

 bergs and ships. In the case of radar installations on surface craft, 

 where speeds are relatively low, tracking the radar target reveals 

 whether or not it is motionless. If it has any appreciable speed, it 

 is apparent that the target is a ship and not an iceberg. However, 

 if the target speed is negligible it may be either a berg or a ship 

 hove-to and only visual methods can identify the target. As the 

 critical areas are frequented by fishing vessels employing hand-line 

 fishermen operating from dories in the vicinity of the mother ship, 

 the problem of identifying a target by means of radar alone is 

 further complicated since the mother ship and dories present a target 

 appearance similar to that of a berg and growlers. In the case of 

 airborne radar, however, where the plane is traveling at about 150 



