91 



break-through southeastward across the usuahy effective natural bar- 

 rier of the ridge extending southwesterly from Flemish Cap. 



Salinity anomalies were again investigated with a view toward 

 determining the departures from average conditions along the common 

 boundary between the Labrador and Atlantic Currents. In the years 

 1934 to 1937, inclusive, the course of the horizontal projection of the 

 surface of zero salinity anomaly in the axis of the intermediate anom- 

 aly maximum gave good results as indicating the boundary between 

 Labrador Current water and Atlantic Current water. In 1938, be- 

 cause of the large volume of Labrador Current water present, the 

 boundary line as indicated by tliis criterion was almost completely 



Figure 25. — Temperature profile southwest of Grand Banks, May 1-2, 1939. 



outside the limits of the surveys. For the same reason the same was 

 true in 1939, the line being outside the limits of the surveys at all but 

 a very few stations. 



In the past, isolated water masses of low temperature and salinity 

 have been found from time to time south of the Grand Baiilcs by the 

 International Ice Patrol as well as by other investigators. In an 

 attempt to learn more of the manner in which such water masses 

 originate, a section running southwest from the Banks and occupied 

 during the second survey was examined. Figure 25 shows a profile of 

 temperature along tliis section. At station 2952 a mass of cold water, 

 with the lowest observed temperature of 0.82° C. occurring at a depth 

 of 75 meters, is typical of the isolated cold, fresh water masses that 

 have repeatedly presented confusing problems to the surv^eyor at- 

 tempting to map the currents in this region of complicated current 



220899 — iO 7 



