During much of the season only one aircraft svas required at Ar- 

 gentia and the second plane remained at its base in the United States. 

 The U. S. C. G. cutters Acushnet and Androscoggin were assigned for 

 surface patrol duty but due to the scarcity of ice their services were 

 not required, and both ships remained at their home ports. A 

 material reduction in the cost of Ice Patrol was effected through 

 these measures. 



Three oceanographic surveys were made by the C. G. cutter 

 Evergreen. During each cruise a current chart was completed while 

 the vessel was still at sea. If patrol cutters were being used, a copy 

 of this chart would be passed to the cutter at sea for use in determining 

 the probable drift of bergs. Such charts are used at the Ice Patrol 

 Office at Argentia for planning ice observation flights and predicting 

 future movements of ice. Details of the oceanographic program are 

 discussed in another section of this bulletin. In general however, 

 surveys during AprU and May revealed that the Labrador Current 

 was not dividing as usual near the northern slope of the Grand Banks, 

 with the western branch running south along the east coast of the 

 Avalon Peninsula. Instead, practically all the current was being 

 diverted to the eastern branch running south along the eastern slope 

 of the banks. This meant that bergs close inshore along the Avalon 

 Peninsula had little driving force to move them south. During the 

 latter part of April and the first part of May, however, bergs driven 

 offshore by the westerly winds were in a position to move south with 

 the eastern branch of the Labrador Current. A survey completed 

 on 16 June showed fairly normal speed but revealed that practically 

 all of the Labrador Current recurved to the east and northeast, north 

 of the 44th parallel, leaving little likelihood of any berg drifting south 

 of that latitude. 



Surface water temperatures collected by radio from vessels passing 

 through the ice areas were another aid in establishing and predicting 

 ice drift and melting rates. Using these temperatures collected over 

 each 2-week period, an oceanographically trained officer on the staff 

 of Commander, International Ice Patrol at Argentia, constructed a 

 surface isotherm chart of sea temperatures. This chart indicated the 

 general features of the Labrador and Atlantic Currents, and the 

 important area where they meet near the Tail of the Grand Banks. 

 Although this type of chart did not give specific values of the velocity 

 of the currents, it did indicate general direction and relative strength, 

 both useful aids in forecasting the drift of ice. Isotherm charts for 

 the 1952 season are shown in figures 1 to 6, inclusive. 



A record of the number of icebergs drifting south of the 48th parallel 

 each year is kept by the Ice Patrol and is used as a yardstick to 

 measure the relative severity of each ice season. Data for the past 

 50 years show that an annual average of 431 bergs cross 48° north 

 latitude. Naturally the annual cost of Ice Patrol cannot be made 



