February 1975 



During the first half of February, three iceberg 

 reports were received. The southernmost, 

 50°18'N 51°08'W, was reported as a large berg 

 on 8 February. Early February saw a very rapid 

 south-southeastward spread of pack ice. Ice 

 conditions on the Grand Banks equalled those of 

 the same period last year, the most severe sea ice 

 year in decades. A mean offshore ice drift dur- 

 ing the period prevented any serious ice conges- 

 tion along Newfoundland's east coast. Ice growth 

 continued during the last half of the month, 

 although at a decreased rate. Ice drifting south 

 added to the pack off Newfoundland. Although 

 the ice cover was above normal, thicknesses were 

 much less than in 1974. By the end of February, 

 sea ice had reached a southeastern limit roughly 

 defined by a line from 45°15'N, 48°20'W to 

 46°10'N, 46°35'W. Iceberg sightings became 

 more numerous as favorable, environmental con- 

 ditions speeded the few icebergs south toward 

 the Grand Banks. Late February preseason 

 flights, 24 February to 12 March (See Figure 3), 

 revealed only 66% of the normal iceberg popula- 

 tion south of Davis Strait along the Baffin Island 

 and Labrador coasts. As in the January surveys, 

 there was a predominance of small icebergs in 

 these upstream regions. The latitudinal iceberg 

 distribution is illustrated graphically in figure 4. 

 A strong southerly flow and an apparent greater 

 than normal mass transport along the Labrador 

 coast from mid-January through February 

 brought the icebergs from coastal Labrador onto 

 the Grand Banks considerably earlier than ex- 

 pected. The southernmost, a small berg was 

 sighted in position 43°58'N, 47°40'W on 1 March. 

 The easternmost iceberg of the month was re- 

 ported on 25 February as a small iceberg 

 (47°08'N, 47°20'W). Although numbers were 

 low and sizes small, an estimated 24 icebergs had 

 already crossed 48°N during February. This is 

 well above the 75 year average of 9 iceberg cross- 

 ings in February. 



March 1975 



With the unexpected acceleration in the south- 

 ward drift of icebergs during February, a num- 

 ber of icebergs began to exit the southeast cover 

 of sea ice posing a threat to trans- Atlantic traffic. 

 Considering this, the 1975 Ice Patrol service was 

 officially started on 4 March. Figure 5 shows the 



iceberg locations as observed during aerial recon- 

 naissance flights on 1 and 7 March. These two 

 flights established the limits of all known ice for 

 the start of the season. The first regular season 

 deployment of the Ice Reconnaissance Detach- 

 ment occurred on 17 March with aircrew and ice 

 observers moving to St. John's, Newfoundland. 

 On 18 and 19 March, consecutive ice reconnais- 

 sance flights (Figure 6) revealed 30 icebergs and 

 10 growlers below 48 °N, but most of these were 

 relatively small in size and showed signs of ad- 

 vanced stages of deterioration. Although sea ice 

 cover was more extensive than normal during the 

 first half of March, the ice east of Newfoundland 

 continued to be thin and of very loose composi- 

 tion. Predominant mild wind flow from the 

 southwest caused early deterioration and reces- 

 sion of the sea ice limits beginning in mid-month. 

 On 26 March, no heavy concentrations of sea ice 

 existed below 48°N although some brash and 

 small cakes of diffused ice extended to 45°N. By 

 the end of March, the concentrated pack had 

 retreated to approximately 49°N with only very 

 diffuse ice extending to 45°N (figure 8). The 

 southernmost iceberg for the month was observed 

 on 27 March (42°50'N, 49°20'W). This was fol- 

 lowed three days later by the sighting of a 

 growler, believed to be the same piece of ice, in 

 position 42°38'N, 49°30'W. A total of 41 ice- 

 bergs crossed 48°N during March. This peak in 

 the iceberg population on the Grand Banks oc- 

 curred a full month earlier than usual and ac- 

 counted for over 40% of the total number of 

 icebergs that would cross 48°N during 1975. One 

 unusual berg sighting was reported outside the 

 Ice Patrol area by the Icelandic cargo vessel 

 SKAFTAFEIL on 28 March. This iceberg was 

 encountered some 400 miles southeast of Cape 

 Farewell, Greenland in position 55°15'N, 

 35°04'W. 



April 1975 



The sea ice edge off Newfoundland/Labrador 

 continued to move northward during April, re- 

 sulting in increased iceberg melt rates for the 

 already rapidly decaying population. The 

 southernmost berg (42°36'N, 50°03'W) during 

 the month was last seen on 1 April. The south- 

 ernmost piece of ice for the 1975 season, a growler, 

 was sighted on 4 April in position 41°44'N, 

 48°45'W. A series of flights on 1, 2 and 3 April, 

 averaging better than 80% visual coverage along 



