to the 1 ,000-dccibar surface. As this area is one from which we have 

 httle information compared to other areas of interest to the ice patrol 



53" 52° 51° 



P'iGURE 28. — Dynamic topography of the 100-decibar surface relative to the 1,000- 

 decibar surface from data collected 6-10 July 1948. 



there are a number of questions which must be answered before measure- 

 ments made in the area can be used with the hope of deducing consequent 

 berg behavior. One of the first questions arising is whether the current 

 pattern at the sea surface is sufficiently similar to that at other levels 

 down to about 150 or 200 meters, so that the general picture of circula- 

 tion at one of those levels may be taken as representative of the net effect 

 of water movements here on bergs which are of sufficient size to survive 

 the journey from this region to positions of potential hazard to trans- 

 atlantic traffic farther south. A comparison of figures 27 and 28 shows 

 that during the period of these observations, the circulation pattern at 

 the two levels was much the same. The circulation pictured indicates 

 that any southward-bound bergs crossing the 49th parallel east of about 

 52°05' W., would continue in the eastern branch of the Labrador Current, 

 and those crossing this parallel west of about 52°20' W., would follow the 

 western bi-anch of the current along the Avalon Peninsula, and those 

 crossing 49° N., at intermediate longitudes would probably strand on 

 the northern slopes of the Grand Banks. 



80 



