Figure 9. — Ice conditions on 17 April 1963. 



to last the time required to travel the 450-500-mile trip. It was now 

 obvious that the one large berg represented the only threat to track C 

 and B, at least until June. This berg moved rapidly south in the 

 Labrador Current for the next few days, grounding in 60 fathoms of 

 water near 46° N., 48° W., on the 21st. It apparently broke up into 

 four small bergs which were sighted on the 25th near 45°25' N., 47°45' 

 W. The current chart of the area from the first oceanographic 

 survey completed in mid-April showed that these bergs were now in 

 an eddy between the Labrador and Atlantic Currents. A flight at 

 the end of the month revealed negligible southern movement of the 

 latter four bergs. The remainder of the offshore bergs had been driven 

 onto the northeast Grand Banks, with a couple aground along Avalon 

 Peninsula. Now it was simply a matter of time until the remaining 

 seven small bergs deteriorated, leaving the entire Grand Banks ice 

 free. The pattern for the 1963 ice season was established. An 

 estimated 20 bergs drifted south of 48° N. during the month. 



With strong variable winds and attendant heavy seas, the sea ice 

 along the north and northeast slope of the Grand Banks rapidly dis- 

 integrated. By 17 April the limits had receded to west of 50° W., 

 with only a 40- by 70-mile area of very open pack ice remaining east 

 of Cape Bonavista. To the northward as far as 54° N., under the 

 influence of consistent east-northeast winds, the limits of sea ice had 

 retreated to within 30 miles of the coast. By the next week no sea 



12 



