46 



warm and salty water and grading off inshore to the colder fresher 

 water of the East Greenland and Labrador Currents. At a depth of 

 1,000 meters the temperature and salinity distribution, as shown in 

 figures 31 and 32, still is characterized by relatively warm and salty 

 water beneath the Irminger and Atlantic Currents. Figures 33 and 

 34, the temperature and salinity at 1,500 meters, show that although 

 beneath the deeper-flowing Atlantic Current the higher temperatui'es 

 and salinities persist, around Cape Farewell this level is below the 

 effect of the Irminger Cm-rent and we find typical intermediate water 

 of the Labrador Sea ^ except in the southern part of the region. 



At 2,000 meters we approach the lower limit of the intermediate 

 water. Figures 35 and 36 give the temperature and salinity distribu- 

 tion at this level and show the central portion of the area to be filled 

 with intermediate water wliile the margins, except beneath the At- 

 lantic Current, show the transition toward deep water character with 

 lower temperature. Another indication of the transition to deep 

 water is the 34.94%o salinity line near the eastern edge of the area. 



Figures 37 and 38 represent the temperature and salinity distribu- 

 tion at 2,500 meters. This level is in the upper part of the deep water, 

 the margins showing lower temperature than the central part and the 

 34.94%o isohalines dehneating the upper portions of the salinity 

 maxima which characterize the deep water. Figures 39 and 40 show 

 the temperature and salinity at 3,000 meters and seem to be well 

 centered in the deep water. In figure 40 the 34.96%o salinity line and 

 its surrounding 34.94%o line indicate a salinity maximum probably 

 originating in the northeastern arm of the Labrador Basin. The 

 34.94%o area between Labrador and Cape Farewell probably had its 

 origin in the northwestern arm of the Labrador Basin. Attention is 

 called to the opinion set forth in United States Coast Guard Bulletin 

 No. 19, Part 2, that these sahnity maxima of the deep water of the 

 Labrador Sea are formed intermittently and follow the general cyclonic 

 movement of the deep water northward along the west Greenland side 

 of the basin and southward along the American side. 



Figures 41 and 42, the temperature and salinity at 3,500 meters, 

 show the transition from deep water to bottom water with indica- 

 tions of the coldest water moving out of the Labrador Basin along 

 the American side. This direction of motion of the bottom water is 

 further indicated in figures 43 and 44 which give the temperature and 

 salinity at 4,000 meters. 



Circulation within the sfrafos^^Aere.— Observation and experience has 

 shown that the direction and velocities of the surface currents as indi- 

 cated by the drift of icebergs are essentially in agreement with dynamic 

 topographic maps referred to the 1,500 decibar level. In the past 



' The intermediate- deep- and bottom-waters referred to here are those described by Smith, Soule, and 

 Mosby in U. S. Coast Guard Bull. No. 19, Pt. 2; not those of Wust which differ in thickness, circulation 

 and origin from the above. 



