In any event it appears that the direct route 

 across Baffin Bay is a very important one for ice- 

 bergs, and one which can provide a late and rap- 

 idly developing threat to the Grand Banks. 



December Northern Iceberg Surveys 



December iceberg survey flights along the Lab- 

 rador and Baffin Island coasts have been made 

 during the years 1963 through 1969. The timing 

 of the December flights has been remarkably con- 

 sistent, all having taken place the first part of 

 December. December flights do not extent farther 

 off-shore from the Labrador coast than 200 miles. 

 Therefore the data does not cover the central 

 Labrador Sea or the west Greenland coast south 

 of 66N. The results of the individual surveys are 

 shown in figures 33 through 39 in terms of ice- 

 bergs per two square degrees. The methods used 

 in plotting and contouring the data are the same 

 as for the fall flights. Figure 40 shows average 

 iceberg conditions based on 4 to 7 year's data. 



The largest iceberg concentration in December 

 is found in the vicinity of Cape Christian, as was 

 the case for the fall surveys. There is some indi- 

 cation that the concentration off Cape Christian 

 increases slightly between fall and winter. As was 

 the case in the fall surveys there is a tendency for 

 icebergs to concentrate north of Cape Dyer. 

 Movement of icebergs directly across Baffin Bay 

 is only slightly discernable in the average chart, 

 however it shows up more clearly in the individ- 

 ual charts, particularly the one for 1969. Continu- 

 ing southward the next major iceberg concentrat- 

 ing area is the hook-like peninsula between Cum- 

 berland Sound and Frobisher Bay. In the en- 

 trance to Hudson Strait there normally appears 

 to be a slight break in iceberg concentration. This 

 is probably related to the flow of currents in and 

 out of the Strait. South of Hudson Strait icebergs 

 again tend to concentrate, probably because of 

 shallow areas extending well off-shore between 

 the Strait and Hopedale. 



January Preseason Iceberg Surveys 



The purpose of the January flights has been to 

 monitor the progress of the icebergs as they drift 

 south toward the Grand Banks, and to estimate 

 how heavy the iceberg season will be. Figures 41 

 through 47 show January iceberg distributions 

 for the various years 1963 and 1965 through 1970 

 in icebergs per two square degrees along the 



Baffiji Island and Labrador coasts. As was the 

 case in the December flights the coverage does not 

 extend offshore more than about 200 miles at 

 most. Figure 48 based on 4 to 7 years data, repre- 

 sents average January iceberg conditions in this 

 area. The general pattern of iceberg concentra- 

 tions is similar to the December pattern with ac- 

 cumulations of icebergs found between Cumber- 

 land Sound and Frobisher Bay, and along the 

 northern Labrador coast. However, the average 

 total iceberg count south of Cumberland Sound 

 increases by a factor of about 2 between Decem- 

 ber and mid-January. The average southern limit 

 of icebergs in both December and January is 

 about 53N. 



The correlation between the number of icebergs 

 in January south of 60N, as far north as coverage 

 has been uniform, and the number of icebergs 

 which drift south of 48N into trans- Atlantic ship- 

 ping routes during March through July is low, as 

 is shown by figure 58. The con-elation coefficient is 

 only 0.19 using a least squares fit between the two 

 variables. Use of data north to 64N, for the years 

 in which it was available, did not improve the 

 correlation. This low correlation between January 

 iceberg potential along the Labrador coast and 

 iceberg severity on the Grand Banks in the fol- 

 lowing months emphasizes the importance of 

 other factors in January, primarily winter winds, 

 in determining the severity of the iceberg season 

 on the Grand Banks. 



February Preseason Iceberg Surveys 



The preseason iceberg surveys carried out in 

 February are the most important preseason Ice 

 Patrol activities of the U.S. Coast Guard. The 

 February surveys are directly related to the op- 

 eration of the Ice Patrol in that during a number 

 of yeais icebei'gs have begun to threaten the 

 Grand Banks in February. Also the results of the 

 February flights are a major factor in deciding 

 when to start routine iceberg patrols of the Grand 

 Banks and daily broadcasts of iceberg positions. 



Unfortunately the so-called February flights 

 have not all been made at the same time each 

 years. In fact thei-e have been years in which 

 flights have not been made in February, but 

 rather were made in early March instead. In or- 

 der to analyse these surveys more uniformly they 

 have all beeii adjusted to a common date of 25 

 February. This was done by "drifting" the ice- 

 bergs sighted on the various surveys forward or 



