autumn is bound to have a distinct effect on next season's Grand Banks 

 iceberg crop. Normally the waters south of Hudson Strait are free 

 of sea ice for 4 months, from early August through late November. 

 It is concluded that bergs which drift past Cape Chidley during this 

 period can hardly expect to survive unless they are large, spend time 

 in protected waters, or get stranded long enough for the pack ice to 

 catch up with them before deterioration. The value of observing and 

 monitoring ice conditions in northern areas during the late summer 

 and autumn and determining the correlation between pack ice and 

 iceberg conditions is emphasized. 



Certain assumptions and conclusions about icebergs were made in 

 Bulletin No. 49 of this series, based on the initial two northern sur- 

 veys made by the Ice Patrol prior to the 1963 season, iceberg data ob- 

 tained from the Canadian Department of Transport in 1961 and 1962 

 and Grand Banks iceberg data recorded over the years. It must be 

 stated that the 1963 conclusions were based on the meager upstream 

 data collected prior to one light and one very light ice season. For- 

 tunately, the number of 1964 Grand Banks bergs w^ere close to normal 

 as was the winter and spring climate. Thus, in addition to having 

 twice as much northern ice data to work with as a result of the 1964 

 preseason surveys, closer to normal conditions prevailed in 1964, which 

 should increase the validity of the 1964 conclusions. There was gen- 

 eral agreement between the 1964 and 1963 conclusions on the following : 



1. Berg group travel time from Cape Chidley to the Grand Banks 

 normally is about 3 months. 



2. Berg group average drift rate from Cape Chidley to the Grand 

 Banks is normally 8-9 miles per day in the winter and early spring. 



3. Bergs are a minimum south of Cape Chidley in November. Most 

 offshore bergs south of Cape Chidley in early November are not 

 normally a factor in the next ice season. 



4. Berg attrition due to deterioration is normally insignificant in 

 winter months from the time bergs are enclosed by pack ice until 

 released by same. 



The 1964 conclusions differed from the 1963 conclusions as follows: 

 1. It is now believed that next year's Grand Banks berg crop is 

 located mainly from Hudson Strait entrance to Bylot Island from the 

 coast to 80 miles offshore in early November, or 200 miles farther 

 north than assumed in 1963. The crop will consist mostly of those 

 bergs that enter the Baffinland Current north of Cape Dyer in the 

 late summer and autumn months. With all this mention of the berg 

 crop, it should be made clear that a given Grand Banks berg crop for 

 the coming ice season is by no means clearly distinguishable. It is not 

 as though bergs suddenly begin to appear off Hudson Strait and exi^t 

 as a sharply defined group from there to Bylot Island in early Novem- 

 ber. As stated before, bergs will probably exist south of Cape Chid- 



82 



