16 



vessel sighted a berg in latitude 45°45' N., longitude 48°47' W., 

 just inside the oO-fathom curve. It drifted slowly westward farther 

 onto the Banks into 43 fathoms of water. It was stated at the time 

 that this berg would probably remain on the Grand Banks and melt 

 during the summer. This remark was based on the assumption that 

 the berg was out of the current and would wander around in the shoal 

 water melting rapidly. It was sighted again by the Patrol ship on 

 June 18 in latitude 45°26' N., longitude 48°50' W., having averaged 

 0.1 knot since last seen, almost due south. June 17 was a day of gales 

 from the west northwest. It moved on the 18th and 19th almost 

 due south with the current map but at the enormously accelerated 

 rate of 0.9 knot and was relocated June 19 in latitude 45°05' N., 

 longitude 48°43' W., now in the strength of the current. It need 

 not be shown that this berg was actually blown off the Banks into the 

 current (as suggested at the time) but only that the wind introduced 

 sufficient wind components into the existing current to so accelerate 

 its flow that it carried the berg south to menace the United States- 

 European routes before it melted. This was the direct cause of pro- 

 longing that season. There were four other bergs in the same area 

 reported on June 7. None of these succeeded in moving off the 

 Banks before melting. The difference, in lieu of other information, 

 must be the gales of June 17. (See Bulletin No. 25, pp. 12 and 13.) 



Other instances of the sometimes determining influences of wind are 

 recorded in 1937. Here the very abnormal and dangerous distribution 

 of bergs in January is directly attributed to early season winds ; surface 

 temperatures and later observations showing no early push of current. 

 (See Bulletin No. 27, p. 2.) Later in that same season it was pointed 

 out that wind effect on areas of field ice played a very major role in 

 bringing bergs to the eastern branch of the Labrador Current and thus 

 south to obstruct the steamer lanes. (See Bulletin No. 27, pp. 3 and 

 4.) And finally in this present season the effect of northwest gales 

 blowing for a long period along the axis of the Labrador Current is 

 thoroughly discussed on page 8 of this bulletin. 



From these examples it can be seen that wind effect, although 

 secondary, is sometimes a determmmg factor and must not be 

 neglected. The general conclusions to be drawn from the above 

 discussion, without being too conservative, are these: (1) That after 

 periods of gales of even 12 hours, or strong winds for longer periods 

 (say 2 days), when the wmd components introduced would tend to 

 augment the existing current, greatly accelerated rates of flow must 

 be anticipated; (2) that after extended periods of gale force, 48 

 hours or more, major ice movements may be initiated. The same 

 would be true for repeated consecutive gales from the same,- or 

 nearly the same, direction. 



Immediately following this section, under Ice Conditions, North 

 Atlantic Ocean, 1938, is a discussion of the ice by months with a 



