The ice in Denmark Strait interfering with passage of vessels 

 is that spreading out from the Greenland coast towards the north- 

 western tip of Iceland. The navigability of the strait is in most 

 cases determined by the width of the channel of open water lying 

 between the outer edge of the pack and the Iceland coast in the 

 vicinity of North Cape. The width of this channel averaged 

 roughly in the neighborhood of 75 miles in February, 50 miles in 

 March, and 25 miles in April. At one time in April the channel 

 was almost closed. In May and June the width of the channel 

 increased to an average of about 40 miles, but constricted in July 

 to about 20 miles, practically blocking the channel on occasion. 

 In August the channel opened rapidly to give about 100 miles of 

 open water. Only in July did the ice show any tendency to spread 

 east along the north coast of Iceland. It should be borne in mind 

 that the outer contour of the ice in Denmark Strait is often very 

 irregular and may contain deep bays, peninsulas, and closed leads. 

 Thus an average position given for the ice edge is at best a very 

 crude estimate. 



The ice conditions prevailing in Denmark Strait during the 1943 

 season when compared with records of other years are evaluated 

 as approximately normal. 



The fjord region of the Greenland east coast between latitudes 

 70°N., and 76°N., was characterized by heavier than normal ice 

 until the end of August. This region was practically inaccessible 

 during the 1943 season. 



ICE DAMAGE TO VESSELS 



Seven vessels were reported damaged by ice, or entrapped in 

 ice fields during the season. One of these sunk as the result of a 

 collision with a berg. An undisclosed number of lives, variously 

 estimated up to 60, were lost in the disaster. Of the other vessels 

 four made port with considerable ice damage. The remaining two 

 continued on their way and are presumed to have suffered only 

 minor damage. Vessels purposely sent into ice infested areas 

 have not been considered. Neither have those subject to super- 

 ficial damage in very light ice. The report from one of the damaged 

 vessels contained no details other than that it made port with 

 heavy ice damage. Of the remainder, three struck bergs and three 

 were damaged by field ice. 



CONCLUSIONS 



A review of the 1943 ice season bearing in mind conditions of 

 previous years leads to the following conclusions : 



1. The crops of icebergs and field ice in the Newfoundland and 

 Grand Banks regions were both somewhat heavier than usual, but 

 far more severe ice conditions have occurred in the past and may 

 be expected from time to time in the future. 



2. Field ice was abnormally heavy in the Gulf of St. Lawrence 



25 



