INTERNATIONAL ICE OBSERVATION AND ICE PATROL, SERVICE. 66 



The depth of the main trunk of the Gulf Stream was found to be 

 greater than 250 meters. The contour of this wall of cold water 

 approximates very closely the 100-fathom contour of the Grand 

 Banks and of the banks farther to the westward. In longitude 55° 

 W., it was found that this similarity of contours did not exist. Here 

 the wall of cold water extended to the southward ; this was probably 

 due to the effects of the cold St. Lawrence drift throiigh the Lau- 

 rentian Channel. During this period the water on the Great Banks, 

 like that of the Gulf Stream, had approximately definite bounds 

 and an approximate temperature of 32° F. On the Tail of the 

 Bank the 32° isotherm extended 30 miles farther south into deep 

 water. It was found that warm water was projected over and on 

 to the west slope of the Great Bank. The finding of both warm 

 and cold water in this area indicates a large ocean eddy. An exami- 

 nation of the records for the same time of year in 1921 shows that 

 similar conditions prevailed then. If a few more years' observations 

 show that similar conditions continue to prevail, it would seem fair 

 to assume that a great eddy exists on the west side of the Tail of 

 the Great Bank at this season. 



While a strong set was observed in the Gulf Stream eastward of 

 the Great Bank, no current was noted while in the cold waters. 

 Where a definite set to the Labrador Current has been found in 

 previous years during April, none was experienced this y^ear in 

 February. In 1921 no appreciable drift was observed in this area 

 during February or early in March. It is thought that there is no 

 drift, or, if any, only a slight one, to the Labrador Current during 

 the late fall and during the winter months. This subject will be 

 discussed in another place, when an effort mil be made to submit 

 proof of the correctness of the above conclusions. 



The direction of the winds experienced while in the vicinity of 

 the Great Bank was averaged for each 12-hour period, and the mean 

 force and direction is indicated by the straight radial lines in the 

 center of chart "H." The Beaufort scale is shown in the lower 

 right-hand corner. The prevalence of northerly and westerly winds 

 is noticeable; there were a few winds from the southwest quadrant, 

 but practically none from the other quadrants. The length of the 

 Unes strikingly illustrates the force of the winds encountered. Nearly 

 all were above a force of 6 of the Beaufort scale. The winds are 

 worthy of consideration for their effect in setting up temporary sur- 

 face cmTents. 



Ice was not found in any large amount during the first part of 

 February, but later in the month large areas of field ice were reported. 

 Many of the local mariners stated that there had been more field 

 ice this spring than for many years past. These fields extended as 

 far south as parallel 45° 30', east to tne edge of the Great Bank, and 

 west to just north of Sable Island, and thence to Cape Canso. The 

 large amount of field ice appears to have been due to a predominance 

 of northwesterly \vinds during the month and during the preceding 

 winter months. Only three bergs were reported, and these were 

 close inshore off St. Johns, Ne^vfoundland. 



Field ice in this vicinity may be of three kinds, viz, Arctic ice, 

 shore and bay ice, and Gulf of St. Lawrence ice. The predominance 

 of northwesterly winds for a long period would tend to increase the 

 quantity of all three. The northerly winds tend to break the Arctic 



