76 



The off-shore part of the western branch moves eastward across the 

 Banks to join the eastern branch on the left and the Grand Banks 

 whorl on the right. It is to this portion of the western branch of the 

 Labrador Current that a considerable part of the movement of water 

 off the Banks is attributed. The southward displacement of such 

 characteristic features as the position of maximum velocity of the 

 Labrador Current, the westward intrusion of Atlantic Current 

 water, and the vortical center usually associated with Flemish Cap, 

 was present again in this survey although not as pronounced as in 

 the first survey. The two cold-water pools found in the first survey 

 became larger and merged into one whose eastward extension was 

 agam noteworthy. The westward mtrusion of Atlantic Current 

 water between about 43°30' N., and 45°00' N., strengthened some- 

 what and, combined with the augmented Grand Banks whorl, suc- 

 ceeded in turning back to the northeastward more of the Labrador 

 Current. 



The current situation found in the third survey, May 26 to June 6, 

 is shown in figure 36. The dynamic isobaths of this survey follow 

 in unusual detail the features of the bottom topography. This is 

 probably attributable to the long-continued period of quiet weather 

 preceding the observations. Gales of short duration apparently do 

 not permanently alter the currents. At least it has been observed 

 that after a few days of gales the berg-drifts are still in accord with 

 a current map made prior to the gales. However, it is also evident 

 from a consideration of the meteorological conditions on the Labrador 

 coast in connection with the transportation of icebergs and volume 

 of flow of the Labrador Current, that average conditions over a period 

 as long as a month are effective in mtroducing wind-current compo- 

 nents. Consequently, it is reasonable that the above-mentioned long- 

 continued period of quiet weather meant the absence of disturbing 

 wind-current components and permitted the currents to follow with 

 unusual fidelity the bottom features. The contribution of water 

 off the Grand Banks was less vigorous than m the second survey but 

 covered a much wider front, the center of the Grand Banks whorl 

 having shifted southward some 60 or 70 miles. As in the first two 

 surveys, the intrusion of Atlantic water retained its unusually southern 

 position. The cold-water pool shown in the first two surveys was 

 still present as indicated by the southeasternmost stations, but the 

 survey did not extend far enough to the south to fully develop its 

 extent. 



