30 MARION AND GENERAL GREENE EXPEDITIONS 



ment at velocities of 6 to 33 miles per day in the axis of the current. 

 The Cape Farewell section (A) just outside of the slope current 

 intersects a slowly rotating anticyclonic vortex approximately 35 

 miles in diameter. Further offshore a secondary band of north- 

 westerly current was entered. It is conjectural whether this outer 

 band was part of the West Greenland Current, split in this locality by 

 this eddy, or was an unrelated stream. It appears from the general 

 trend and direction of the dynamic isobaths on figure 122, page 167, 

 however, that this current shown on the extreme southwestern end 

 of the Cape Farewell section was approaching from the south and 

 west, in contrast to the main portion of the West Greenland Current, 

 which hugged the continental slope, rounding Cape Farewell from 

 the north and east. The source of this outer band of current, which 

 it is believed may have considerable significance in the general scheme 

 of circulation for the entire Labrador Sea, is discussed on page 32. 

 Regardless of its origin, however, it joined the trunk of the west 

 Greenland stream as the latter increased to its maximum velocity of 

 33 miles per day off Ivigtut. (See fig. 8.) Immediately north of 

 Ivigtut the current began to throw off branches along its outer side, 

 all of which turned westward into the Labrador Sea. As Fylla Bank 

 was approached the rate of flow diminished. Just north of Fylla 

 Bank the West Greenland Current experienced major westward 

 branching, the bulk of its surface waters being deflected here, prob- 

 ably by meeting the southern face of Little Hellefiske Bank. 



Inshore portions of the West Greenland Current continued north- 

 ward hugging the slope and flowing at the much reduced rate of 6 

 miles per day. Narrow bands of current, probably continuations 

 of the more vigorous parts of the system, were found along the slopes 

 of Great Hellefiske Bank. Such streams (fig. 8) entered Disko Bay 

 entrance on the south and discharged on the north. A weak but 

 appreciable set of West Greenland Current, more clearly distin- 

 guished in the Disko Island section (fig. 11) below the surface, 

 flowed through Davis Strait Channel into Baffin Bay. 



CROSS SECTIONS OF THE CURRENTS 



A total of seven hydrographic sections taken during the summer 

 of 1928 (fig. 7) more or less normal to the coa.st, and more or less 

 equall}^ spaced between Cape Farewell and Disko Island, afford a 

 means of studying the West Greenland Current below the sea surface 

 and along its course northward to the entrance of Baffin Bay. 



The discussion in this and the following three chapters is lim- 

 ited to the circulation of the upper water layers (sometimes re- 

 ferred to as the troposphere), in the depth of which has been de- 

 termined by reference to a common isobaric surface. It has been 

 found for the west Greenland sector that motionless water (or 

 nearly so) prevails usually between 1,500-2,000 meters. The 1,500- 

 decibar level has served, therefore, for all practical purposes as the 

 datum plane upon which the calculations of direction and velocity 

 of the currents are based. 



Gape Farewell. — A cross section of the West Greenland Current,® 

 off Cape Farewell (fig. 9), shows, as does the surface map (fig. 8), 



* For a description of the method employed in the construction of the velocity profiles 

 see p. 21. 



