92 



north of the Azores and was comparable to that at about Iselin's 

 station 231. Thus there is reason to beUeve that if the survey made 

 on the 1937 post-season cruise had extended farther to the south and 

 east we would have found additional current moving eastward across 

 the Atlantic before we reached the branch or branches which recurve 

 toward Bermuda. 



SUMMARY 



1. Three current surveys of the region immediately eastward of 

 the Grand Banks were made during the 1937 ice season and an addi- 

 tional survey extending farther to the south, east, and north was 

 made on a post-season cruise, and the current patterns found have 

 been described. 



2. The seasonal variation in the volume of flow of the Labrador 

 Current during 1937 has been quantitatively determined and com- 

 pared with conditions existing durmg the previous three ice seasons. 



3. The volume of water contributed eastward across the Grand 

 Banks by the western branch of the Labrador Current which flows 

 southward along the Avalon Peninsula of Newfoundland was greater 

 than usual during 1937 and has been discussed in relation to iceberg 

 data and the flood of the West Greenland Current past Cape Fare- 

 wefl in 1935. 



4. The boundary between Atlantic Current water and Labrador 

 Current water, on the basis of the horizontal projection of the course 

 of the zero salinity anomaly at the intermediate salinity anomaly maxi- 

 mum, has been shown with relation to the position of the 4-year average 

 1934-37. 



5. The abnormally large quantity of mixed water found east of the 

 Grand Banks during the 1937 post-season cruise mdicated the great 

 variability in current pattern to which this area is subject and has 

 been considered with respect to extra-southerly berg-drifts. 



6. Temperature-salinity curves representmg conditions found on 

 the post-season cruise have been compared with those from other 

 observations north of the Azores and in the Sargasso Sea and indicate 

 that the sections made on the post-season cruise did not completely 

 cross the Atlantic Current. 



7. The post-season cruise presents additional evidence that a most 

 nearly motionless level exists, in the region surveyed, at a depth of 

 about 2,000 or 2,500 meters; and that below this level the deep water 

 is in motion in a direction counter to the overlying Atlantic Current. 



It is evident that oceanic circulation in these areas is of fundamental 

 importance in controlling the distribution of menacing ice. The re- 

 sults reported on here should be regarded as steps made toward the 

 solution of the larger problem of tliis continuing investigation, rather 

 than as entities complete in themselves. 



