series) is based mainly on sea level atmospheric pressure anomalies 

 in the North Atlantic during the preceding winter. Bergs spend their 

 lifetime in basically an oceanographic environment which is largely 

 determined by weather. Weather is a most important factor in the 

 birth, lifetime career, and death of bergs. Undoubtedly summer 

 weather in Baffin Bay and along the berg-producing glaciers in north- 

 west Greenland has a distinct influence on the production of bergs, 

 their subsequent distribution, and their deterioration there. The 

 climate of the areas inhabitated by those bergs that have successfully 

 reached the south-seeking Baffinland-Labrador Current system at the 

 proper time must be assumed to be most critical in controlling or 

 altering control of the drift and deterioration of the berg crop. The 

 percentage of the available supply that reaches the Grand Banks is 

 largely determined by the winter and spring weather along the east 

 coasts of Baffin Island, Labrador, and Newfoundland. The distinctive 

 character of each ice season is finally determined mainly by the winter, 

 spring, and early summer weather in the vicinty of the Grand Banks. 

 An average Grand Banks ice season, based on records since 1946, is 

 three and one half months duration from early March to late June. 

 The average ice season is governed by the climate of the continental 

 shelf from glacier to the Grand Banks. Normal winds are favorable 

 for iceberg drift to the Grand Banks in the winter but are neutral or 

 unfavorable in the late spring and summer making it especially diffi- 

 cult for bergs to travel fast enough to survive to the Grand Banks 

 after July. Add to this the fact that sea ice normally retreats to north 

 of Labrador by the end of July and does not reappear in this area 

 mitil late November, and the character of an average ice season becomes 

 more easily understood. 



The annual menace of icebergs to shipping near the Grand Banks 

 of Newfoundland would not exist without the Baffinland-Labrador 

 Current system. It must also be realized that the proportions the ice- 

 berg menace assumes each year is mostly governed by the weather. 

 If the normal climate of the Baffin Bay, Davis Strait, and Labrador 

 continental shelf were a couple of degrees warmer, an iceberg on the 

 Grand Banks would be a rarity indeed. On the other hand, if the 

 normal climate of the above regions and the Grand Banks was a 

 couple of degrees colder, there would probably be hundreds of icebergs 

 in the major shipping lanes 5 to 6 months a year annually. Abnormal 

 winter weather has usually resulted in abnormal iceberg seasons. The 

 winter and spring 1956-57 climate was abnormally cold in the Grand 

 Banks, Newfoundland, Labrador area resulting in a 1957 ice season 

 of 614 months and hvmdreds of bergs invading the shipping lanes. 

 The weather in 1957-58 was abnormally warm resulting in the lightest 

 iceberg season on record in 1958, not a single berg surviving to the 

 Grand Banks. A study of Ice Patrol records and weather records 



40 



