100 MARION AND GRNKRAL GREENE EXPEDITTONS 



salinity profiles, H, J, and O, record water in on the bottom of the 

 slope which is saltier than that shown on any of the other profiles. 

 Where the depth of the shelf below the sea surface is as great as 

 600 meters as off Resolution Island, Baffin Land (section J, fig. 62) , 

 bottom water as salty as 34.7%o was found. When such evidence 

 is compared with that contained on the horizontal projections, where 

 relic pools of salty water were noted in many of the shelf depres- 

 sions, it all strongly suggests that the removal of low-salinity surface 

 water is more or less compensated by intrusions of West Greenland 

 Current water over the bottom. That such movements occur in 

 the shelf column, with a component lateral to the main transport 

 of the Labrador Current, appears reasonable, but the fact that such 

 currents are not directly measurable, or revealed on the dynamic 

 topographic maps, indicates that, if they do actually exist, they must 

 be weak, irregular, and transitional. It must be realized, neverthe- 

 less, that any picture of the circulation based solely upon the dis- 

 tribution of the temperature and the salinity is not conclusive, and 

 whether or not the Labrador Current at times has torsional as well 

 as translatory motion, merits further investigation. 



During the summer of 1928 water colder than 2° C. extended to a 

 depth of 500 meters on the Baffin Land slope as shown on sections 

 H and I (fig. 62). As previously remarked in the discussion of the 

 temperature charts, this is the under side of the Baffin Land Current. 

 The further fact that water as cold as this was not found farther 

 south off Hudson Strait, section J, at a depth greater than 250 meters 

 indicates considerable mixing occurred at these levels on the Baffin 

 Land slope between the Baffin Land Current and the warmer West 

 Greenland Current. The fact that the core of coldest water in sec- 

 tions J and K was warmer than the corresponding water shown in 

 the sections both north and south indicates either more extensive 

 warming there by the West Greenland Current or that the water in 

 question came from sources other than the Baffin Land Current. 

 Reference to the surface current may (fig. 122, p. 167) indicates that 

 the higher temperatures off Resolution Island resulted from the 

 West Greenland Current, w^hile those off NacHivak Fiord were con- 

 tributed from Hudson Strait. Much of the Baffin Land Current 

 water at times apparently makes the circuit into Hudson Strait. 



Attention is particularly invited to the relatively warm, salty 

 water found on the Baffin Land slope as shown by the temperatures 

 higher than 4° C^ and salinities of 34.86 to 34.89%o, at the outer 

 end of sections I, J, and K (figs. 62 and 63). When these profiles are 

 compared with corresponding velocity profiles and also with the 

 temperature and salinity maps, the source of the warm salty water is 

 traced toward Greenland. 



The water of the slope current, Frobisher Bay to mid-Labrador at 

 depths below the seasonal influence, was found to be warmer than the 

 slope current at similar levels farther south, an apparently paradoxi- 

 cal fact that as the water in the slope band moves southward it cools. 

 Incidentally this introduces a new conception of the Labrador Cur- 

 rent which heretofore has been regarded primarily as an icy stream 

 from the far north. 



