0^^ 5? 58" ST" 56*" 55' 64" 55* 52' 51' 50' «9' 4e" «?• 46* 45" 



Figure 20. — Ice conditions Grand Banks on 16 April 1964. 



85 bergs were driven eastward and permanently out of the Current by 

 19 April. The next large group of bergs were driven eastward out 

 of the Current and across the 1000 fathom curve along 49° N. be- 

 tween 47° W. and 49° W. With a little northerly wind these bergs 

 could easily drift back into the main branch of the Labrador Current. 

 On 19 April numerous bergs were scattered along the northern 

 Grand Banks from the coast to Flemish Cap. The weather pattern 

 abruptly changed with average strong northerly winds dominating 

 until the end of April. See figure 40, the mean sea level pressure 

 chart for the period 17 April-4 May 1964. As a result, bergs were 

 driven south about 130 miles in 11 days. At the end of April, bergs 

 were spread out from 54°30' W. and the east coast of Newfoundland 

 to 46° W. from 45°20' N. northward with the greatest concentrations 

 located south of Cape Race and on the central Banks near Virgin 

 Rocks. An estimated 235 bergs crossed south of 48° N. from 19-30 

 April. All but about 20 of these bergs were removed from the main 

 branch of the Labrador Current, with most of them probably perma- 

 nently removed as a threat to Track B, then in effect. Of major 

 concern now was the movement of the 20 bergs in the Current near 

 46° N., 47°30' W. These bergs could reach the Tail of the Banks within 

 a week and Track B within 10 days. While most of the bergs on the 

 Grand Banks were permanently removed from the main branch of the 

 Labrador Current, they were expected to be a menace to ships using 

 the northern tracks for some time. The many smaller and southern- 

 most bergs were expected to deteriorate within 2 to 3 weeks. The 

 larger bergs in the colder waters near the coast, the larger bergs 

 aground in the colder waters on the northern Grand Banks, and those 



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