SUMMARY 



The most noteworthy feature of the 1947 ice season was the 

 destruction of nearly all of the year's crop of ice during February 

 as a result of abnormal onshore winds. 



Compared with other years, the distribution and quantity of field 

 ice was about normal on the first of February. It extended south- 

 ward over the northern slope of the Grand Banks, and such in- 

 formation as was received concerning the upstream boundaries in- 

 dicated a normal distribution. By mid-March however, most of the 

 field ice south of Hamilton Inlet had been destroyed. Following the 

 restoration of normal wind conditions, field ice, some of which was 

 remarkably heavy, again spread southward along the Labrador 

 coast and by mid-April had again reached the northern slope of the 

 Grand Banks and attained its maximum southeasterly extension on 

 the 24th of April. Strong westerly winds following the 24th shifted 

 the field seaward, where the higher temperatures of the offshore 

 waters and scattering by the winds accelerated the destruction of 

 the ice. By mid-May no field ice remained south of the 51st parallel, 

 and by the middle of June no field ice remained in the area south of 

 the 54th parallel. 



The limits of the ice emerging from the Gulf of St. Lawrence also 

 show to some extent the influence of the abnormal easterly winds. 

 In early February this field spread eastw^ard to Burgeo Bank and 

 southeastward past Scatari Island. By mid-March the only ice re- 

 maining outside of Cabot Strait was a narrow belt against the beach 

 of Cape Breton Island north of Scatari Island. Following the mid- 

 dle of March the field ice again moved out from the Gulf of St. Law- 

 rence, but at no time did the field extend south past the 45th parallel 

 nor did it block navigation inside Sable Island or navigation to 

 Louisburg. The river and gulf were open at an early date, much of 

 the route being reported navigable by the first week in April. 



The total number of bergs that drifted south around and over the 

 Grand Banks during the season was unusually small. Only 63 bergs 

 are estimated to have drifted south past the 48th parallel during 

 the season and of this number only three are known to have crossed 

 the 45th parallel. These same three bergs are the only ones known 

 to have reached positions menacing traffic following the effective 

 United States-European routes of the North Atlantic track agree- 

 ment. These include the berg reported by the S. S. Esso Glasgow 

 on the 2d of June in position 40°50' N., 46°42' W. ; the berg reported 

 by the S. S. William Wheelwright at 42°28' N., 53°34' W. on the 6th 

 of July; and the berg reported on the 19th of July at 44°10' N., 

 44° 13' W. Figures 1 to 6 show the ice distribution for each of the 

 months from February through July. 



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