86 



Figure 22 shows the results of the third survey. As previously noted, 

 this was planned to be a double survey in which the area was to be 

 remapped as quickly as possible. The solid lines shoAV the map 

 resulting- from the early work and the broken lines represent condi- 

 tions found about a week later. To avoid crowding, the lines usually 

 drawn for every 2 dynamic centimeters have been omitted in the 

 region of the swifter currents. Considering the solid lines of figure 



53° 52° 51° 50° 49° 48° 47° 46° 45° 



Figure 22.— Dynamic current map, from data collected May 21-June 1, 1939 



22 with reference to the previous survey as illustrated by figure 21 it 

 is seen that south of the Tail of the Banks the area of cold mixed 

 water grew considerably in extent, the isobath of 971.1 dynamic 

 meters moving from a latitude of about 42° N., at longitude 50° W., in 

 figure 21 tolatitude41° N., at the same longitude in figure 22 (solidlines). 

 During the same period the tongue of cold mixed water extending 

 southeastward again increased in width and extent. The Atlantic 

 Current border in the eastern part of the map showed a slight gain 

 to the westward as compared with the previous map, but the extreme 

 easternmost station indicated that northward of the limits of the sur- 

 vey the cold mixed water had increased greatly in volume. The 

 Labrador Current was still flowing with unusual strength. Com- 

 paring the first part of the survey (solid lines) with the second part 

 (broken lines) it will be seen that during the week which elapsed 

 between the two parts of the survey the Gulf Stream had made a 



