DAVIS STRAIT AND LABRADOR SEA 85 



Frohisher Boy. — Section I (fig. 48) was taken 2 days following 

 section H and at a point on the slope 50 miles farther south. A strik- 

 ing difference will be noted if the two sections be compared. Tlie 

 volume of the shelf current (sec. I, fig. 48), of 1.7 million cubic 

 meters per second, remained practically unaltered, but the outer band 

 of the current bounded by the 1 centimeter-per-second line, had in- 

 creased in draft from 300 to 1,200 meters and in consequence a volume 

 of 3.3 million cubic meters per second, about double the volume of 

 the current farther north. This deepening and swelling of the 

 south flowing current between Cumberland Gulf and Frobisher Bay 

 was due to tlie Baffin Land Current being joined by significant por- 

 tions of the West Greenland Current. The net volume of the west- 

 erly set between stations 984 and 986 (fig. 153, p. 202) was computed 

 as 1.9 million cubic meters per second. If this sum be added to the 

 volume of the Baffin Land Current through the Cumberland Gulf 

 section, it closely equals the computed volume of the flow through 

 the Frobisher Bay section. Subsequent examination of the temper- 

 ature and salinity profiles and maps of this region (p. 99) also re- 

 veals a sharp contrast in the physical character of the abutting Baffin 

 Land and West Greenland Currents. 



The temperature and salinity correlation curves for sections H and 

 I (fig. 49) also reveal the difference in derivation of the water com- 

 posing the current there. The right-hand portion of curve I with a 

 maximum temperature of 4.1° C, and a salinity of 34.86%o, indi- 

 cates the relatively greater contribution of the West Greenland Cur- 

 rent at this point on the Baffin Land slope than farther north off 

 Cumberland Gulf. 



Finally, to dispel any doubt as to the difference in derivation of 

 the currents recorded by the two sections, one need only regard their 

 respective rates of heat transfer. It is, of course, well known that 

 the Baffin Land Current is essentially frigid in character ; a compu- 

 tation of the average temperature of the current past Cumberland 

 Gulf was 0.3° C, and the rate of heat transfer was 0.5 million cubic 

 meter degrees centigrade per second. After being joined by the 

 West Greenland Current, however, and known as the Labrador Cur- 

 rent (sec. I) the average temperature was 4.2° C, and the rate 

 of heat transfer mounted to 22.9 million cubic meter degrees centi- 

 grade per second. The only possible source of so much warmth in 

 this part of the sea is the West Greenland Current. 



Consideration of the foregoing and other computations on the 

 volume of the West Greenlancl Current and the Baffin Land Current 

 indicate that they combine in proportions of approximately 3 to 2, 

 respectively. 



A core of northerly countercurrent not reaching up to the surface 

 and amounting to 1.3 million cubic meters per second does not 

 materially alter the main features noted on the Frobisher Bay 

 section. 



Resolution Islcmd. — Section J (fig. 48) taken August 19-20, 1928, 

 about 50 miles south of section I, shows that the shelf current pro- 

 ceeding southward decreased both in velocity and volume, the com- 

 puted transport being 0.6 million cubic meters per second. The 

 surface current map (fig. 47) reveals that a large proportion of the 

 shelf current recorded on section I passed through Gabriel Strait 



