The effect of sea ice on the movement of bergs is truly unknown and 

 can only be assumed. The importance of sea ice on the iceberg prob- 

 lem in general has already been discussed. It is strongly believed that 

 icebergs would be nonexistent at the Tail of the Banks and rare on 

 the northern Grand Banks if there were no sea ice along the Labrador 

 coast. Sea ice, especially when in the form of close pack thick winter 

 ice, must have a considerable influence on the movement of bergs, both 

 directly and indirectly. Annually from December through May sea 

 ice generally covers the entire continental shelf and considerable 

 portions of the continental slope of Baffin Island and Labrador. As 

 winter advances the sea ice spreads farther south reaching a maximum 

 during late March and early April in the vicinity of the Grand Banks. 

 Assuming that the Grand Banks berg crop must be south of Cape 

 Dyer by late Januaiy and south of Cape Chidley by early March, 

 fast ice is not considered a very important factor in trapping the 

 bergs and halting their motion. The forces of the Baffinland- 

 Labrador Current system, the wind, and the tides, being what they are 

 in this area, prevent significant formation and duration of fast ice 

 from Cape Dyer south. True, fast ice of a winter's duration is 

 probably formed in well protected bays and inlets such as Cumberland 

 Sound and Frobisher Bay. However, most bergs in those areas are 

 smaller-sized than normal and for the most part are permanently 

 trapped and already removed from the Grand Banks potential. Fast 

 ice of relatively short duration may exist inside the headlands and 

 island chains from Cape Dyer to the south but any significant effect 

 on delaying bergs is dubious as a combination of the forces of the 

 current system, wind, tides, and bottom topography are believed 

 dominant. 



While the effect of the winter's fast ice on delaying the next sea- 

 son's Grand Banks berg crop has been somewhat discounted, the 

 effect of the Baffin Bay-Labrador pack as a whole on the crop move- 

 ment may be very significant. For example, aerial ice observations 

 indicate that bergs enclosed in thick winter close pack ice are gen- 

 erally inclined to move with the pack. Forces of wind, current, and 

 tide actmg on close pack ice seem to be transferred to the enclosed 

 bergs and vice versa, with the result that they tend to move together 

 with bergs locked in the embrace of the pack ice. This is not true 

 when the pack ice is young or when open water areas exist near a berg, 

 as the different forces acting on berg and pack ice are sufficient to over- 

 come any restraint of one on the other. Naturally if a berg grounds 

 and other forces tend to keep it aground, the pack ice will bypass the 

 berg leaving a lee in the direction of movement. Smaller and medium 

 bergs are more likely to stay locked in with the pack ice for longer 

 periods than larger bergs. The disparate forces acting on the larger 

 bergs and pack ice are more likely to be of sufficient magnitude to 



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