occurred in the first week of May, as shown ap- 

 proximately in Figure 8, and was about 250 miles 

 north of the average southernmost extent. By 20 

 May sea ic« retreated northward somewhat, and 

 the sea ice south of Belle Isle Strait separated from 

 the main pack along the Labrador coast, thus form- 

 ing a patch of sea ice which remained off the north- 

 east coast of Newfoundland in the Notre Dame 

 Bay area until early June when it finally disap- 

 peared. The first iceberg confirmed to have crossed 

 48° N. was reported 9 May in position 47°55' N., 

 46°50' W., as indicated in Figure 8. The eastern- 

 most reported penetration of an iceberg was to 

 46°30' W. on 24 May. This report, from a ship, is 

 shown on Figure 9. The southernmost iceberg 

 penetration reported this season is shown on Fig- 

 ure 12. This was a radar target which was identi- 

 fied as an iceberg by airborne microwave 

 radiometer in position 43°50' N., 50°05' W. on 

 20 June. Undoubtedly these southernmost and 

 easternmost reported icebergs may have drifted 

 somewhat further south and east before they dis- 

 integrated. On 28 June there was an unconfirmed 

 report of a growler at 42°20' N., 44°50' W. There 

 was also a ship report of a small iceberg at 41°10' 

 N., 52° 10' W. on 1 April. Extensive aerial recon- 

 naissance of the area of this report revealed no 

 iceberg and it was concluded that this report was 

 almost certainly an incorrect identification. 



One of the most interesting features of the 1969 

 iceberg season was the failure of the expected 

 heavy ice season to materialize. In view of the 

 large number of icebergs observed on the Septem- 

 ber/October 1968 survey, more than the average 

 number of icebergs had been expected to drift 

 south of 48° N. As it turned out there were sig- 

 nificantly fewer than average icebergs south of 

 48° N. in 1969. The weather along the path of ice- 

 berg drift, in the winter appears to be the predom- 

 inant factor influencing the survival of icebergs 

 to the shipping lanes in the vicinity of the Grand 

 Banks. Figure 16, which presents the normal, and 



the 1968-1969 average monthly surface pressure in 

 the iceberg areas, shows qualitatively why the 

 heavy ice season did not materialize. Assuming 

 that the wind effect on icebergs is such that they 

 will drift somewhat to the riglit of the geostrophic 

 wind, Figure 16 shows that generally the 1968- 

 1969 pressure patterns were somewhat less favor- 

 able than normal for the southward drift of ice. 

 In addition the pressure patterns were so oriented 

 that there was a tendency for the ice to drift shore- 

 ward and become entrapped in the fjords of Baf- 

 fin Island and Labrador. Particularly noteworthy 

 patterns of pressure appear in January and Feb- 

 ruary of 1969. In January the normal northerly 

 flow of air along the Labrador coast was replaced 

 by a circulation from the northeast, and in Feb- 

 ruary tlie normal northerly flov/ along the coast 

 was replaced by a flow from the southeast. The 

 effects of this was not only to directly oppose the 

 southward drift, of ice, but also to advect warmer 

 than normal air in toward the Labrador coast, 

 thus hastening the deterioration of icebergs. 



The warm air also inhibited the formation and 

 drift of sea ice. Sea ice serves to protect icebergs 

 from the eroding action of the surrounding water, 

 and to a certain extent, hinders the movement of 

 the bergs. Thus the reduced amount of sea and ice 

 had an adverse effect on the southerly movement 

 of the bergs. The bergs, being relatively unhin- 

 dered by sea ice and under the influence of the pre- 

 vailing winds, drifted into shallow bays and inlets 

 where they grounded. They were also subjected to 

 accelerated erosion by the surrounding water. The 

 strength of this warming effect is readily apparent 

 in Figure 17 which shows normal and 1968-1969 

 frost degree days for selected stations along the 

 Baffin Island, Labrador, and Newfoundland 

 coasts. 



Bi-monthly sea surface temperature charts for 

 the 1969 ice season are shown in Figures 18 

 throuffh 25. 



16 



