48 



reliable charts of the bottom temperature in situ and the potential 

 bottom temperature. These charts are shown in figures 52 and 53, 

 respectively, and apply to depths greater than 1,500 meters. The 

 stations at which actual bottom temperatures were obtained are 

 marked with a cross. The considerable horizontal gradient is in 

 accord with the circulation of the deep and bottom water discussed 

 above and shown in figures 49-51. The lowest temperatures may be 



Figure 62.— Bottom temperatures in situ for depths greater than 1,500 meters. July 10- August 23, 1935. 



looked upon as most characteristic of the bottom water of the Labrador 

 Sea and in this light it is interesting to note that along the American 

 side the axis of minimum temperature follows the channel of greatest 

 depth as the water progresses toward the Newfoundland Basin. In 

 figure 53 the potential temperature has a minimum at about 55° N., 

 50° W. and another southwestward of Cape Farewell. Considering 

 the seasonal production of the deep water of the Labrador Sea, such 

 minima are to be expected. Furthermore, their temperature and 

 extent may also be expected to vary with the varying severity of the 

 winter of their production. It is doubtful, however, if the location 

 of minima from successive winters can be used for the determination 



