Strait increased until it extended as far east as 

 51W. The maxinmm extent of sea ice in May is 

 shown approximately in figure 10. Flight opera- 

 tions during the first half of May were hampered 

 by poor visibility in the iceberg patrol areas and 

 definite information on the iceberg threat during 

 this period i^ sketchy. Comparing the informa- 

 tion obtained on the good series of flights on 16- 

 18 April with the next good series on 17-20 May, 

 it appears that the net movement of icebergs 

 between mid-April and mid-May was only from 

 near 49-30N 53-OOW to the southern edge of the 

 sea ice near 49N 52W (figure 10). Many radar 

 targets were reported in the Grand Banks area 

 during the first half of the month, however, it 

 is believed that very few of them were icebergs. 

 The only positive indication that some of the 

 radar targets may have been icebergs drifting in 

 advance of the general mass of icebergs further 

 north was a ship report of an iceberg near 48- 

 OON 49-OOW on 16 May. The few icebergs that 

 had drifted to the Cape Race area in late April 

 were last seen on 1 May. They evidently melted 

 during early May, and no other icebergs are be- 

 lieved to have been present in the vicinity of the 

 Avalon Peninsula during ]\Iay. During the last 

 few days of May, icebergs began to drift south 

 and east of Cape Bonavista. On 30 May about 25 

 icebergs and several growlers were reported 

 strung out to 200 miles eastward of Trinity Bay. 

 It is estimated that only two icebergs drifted 

 south of 48N during the month of May 1970. 



June 



The month of June saw the only significant 

 threat by icebergs to the Grand Banks area. 

 Flights on 5 and 6 June (see figure 11) indicated 

 that the icebergs sighted strung out eastward on 

 the flight of 30 May were beginning to drift down 

 the eastern slopes of the Grand Banks. On 7 

 June there were numerous reports from shipping 

 of icebergs in the general vicinity of 48N 48W, 

 as well as reports of icebergs near 46N 47W. Ice- 

 bergs continued to drift south, and on 10 June 

 an iceberg was reported at position 45-35N 47- 

 45W. This iceberg, shown on figure 13, was the 

 southernmost reported iceberg for the 1970 sea- 

 son and was about 120 miles north of the 1946-65 



average position of the southernmost iceberg of 

 the season. A series of flights on 14, 15, and 16 

 June covered most of the area between 43-20N 

 and 49-OON, and showed that there were approxi- 

 mately 12 icebergs to be found south of 48N, and 

 approximately 80 icebergs strung out towards the 

 east from Newfoundland between 48-OON and 

 49-OON (see figure 12). A flight on 27 June 

 found approximately 100 icebergs between 48- 

 30N and 50-OON, thus indicating that there were 

 still icebergs to be found on routes into the Strait 

 of Belle Isle as of late June when sea ice had 

 cleared from the entrance to the Strait enough 

 so that shipping could pass through the Strait. 



It is estimated that approximately 70 icebergs 

 drifted south of 48N during the month of June. 



At the beginning of June the southern extent 

 of sea ice was to approximately 50N. By the end 

 of June all sea ice had cleared to north of Belle 

 Isle Strait. Sea ice conditions during June were 

 approximately normal in comparison to the Ice 

 Atlas. 



July 



Flight operations in early July were hampered 

 by poor visibility. However, based on ship reports 

 and occasional flights it became apparent that 

 very few icebergs were drifting south of 48N, 

 although reports from shipping through Belle 

 Isle Strait indicated that there were numerous 

 icebergs still to be found north of olN. A series 

 of flights between 19 and 23 July, see figure 13, 

 and reports from shipping indicated that there 

 was little iceberg threat remaining for the Grand 

 Banks during the 1970 season. The easternmost 

 iceberg observed during the 1970 season was 

 found on 3 July at 48-50N 44-15W, somewhat 

 less to the east than the 1946-65 average. It is 

 estimated that 8 icebergs drifted south of 48N 

 during the month of July. There was no known 

 sea ice south of Belle Isle Strait. 



Augusf 



During August there were three reports of 



itween 48-00 and 50-OON as well as 

 numerous reports of icebergs in the approaches 

 to the Strait of Belle Isle. There were no known 

 south of 48N in August. 



15 



