Figures 7, 8 and 9 show the dynamic topography of the sea sur- 

 face relative to the 1,000-decibar surface as found during the first, 

 second and third surveys respectively. In figure 7 the margins 

 of the Atlantic Current are to be seen in the southwestern part 

 of the surveyed area, in the salient whose axis points northwest- 

 ward from 44° N., 46° W., and again at the 46th parallel just 

 southward of Flemish Cap, The salient, which is the dominating 

 feature of figure 7, seems to have been effective in blocking the 

 southward flow of the Labrador Current. The shape of the 

 salient in figure 7 is not such as to produce the considerable diver- 

 sion of the Labrador Current eastward north of the 44th parallel 

 which is shown in the chart. However, what past evidence is 

 available indicates that such salients or meanders progress in a 

 northeasterly direction and it is probable that the diversion of the 

 Labrador Current was accomplished at some time prior to the first 

 survey when the Atlantic Current salient was centered more to 

 the .southwest. 



Had any bergs been in the area immediately northward of that 

 covered by this survey figure 7 would have indicated two potential 

 danger areas for close surveillance by the patrol. One of these, 

 at the southern edge of the surveyed area, was in the neighborhood 

 of the 49th meridian where bergs might have moved southward 

 after following the eastern edge of the Grand Banks. The other 

 was centered at about 45° N., 45° W., where bergs diverted east- 

 ward north of 44° N., could again move south and southeastward 

 toward the steamer lanes of the North Atlantic Track Agreement. 

 Very little Labrador Current, however, reached southward of the 

 44th parallel and an outstanding feature of this survey, not shown 

 by the dynamic topography, was the exceptionally high tempera- 

 ture of the water in the area. Negative temperatures were found 

 at only 15 of the 79 stations and all of these were north of 44° N. 

 The number of stations at which temperatures lower than 3° C. 

 were found was 32, and those where temperatures were in excess 

 of 15° C. totaled 17. These figures are to be compared with a 

 similar cruise in 1950 when, of 69 stations occupied, 47 had tem- 

 peratures below 3°, 34 had negative temperatures, and 3 had 

 temperatures above 15°. 



The second survey was made in an area from which relatively 

 few previous observations are available. Our knowledge of the 

 circulation here is based largely on inference. From the 1,000- 

 meter isobath in figure 8 it will be seen that a large part of the 

 area is situated in shallow water so that, if the dynamic topog- 

 raphy is to be referred to the 1,000-decibar surface, 57 of the 79 

 stations must be adjusted for their shallow depth. Thus the pic- 

 ture of circulation deduced from the density distribution and 



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