- 12 - 



(c) Density ((T^) 



Figures 12, 13 nnd 14 show the distribution of density ((J^) gt 

 the 1, 25, and 50 metre levels. In the Bay itself at 1 m., densities 

 vnry from less thnn 22.5 in Chignecto Chnnnel to a value greater thsn 

 24. 9 In the Digby area. Southv/est of Grand Manan there exists a 

 body of denser water, clearly the result of strong tidal mixing in 

 the area south of Grand Mon^^n, of the warmer and lighter surface waters 

 flowing out of the Boy smd the colder and he^^vier water from below 

 50 metres flowing into the Bay. This heavier surface water is due to 

 upwelling and must sink below or mix with lighter waters as it passes 

 away from this area. Another pertinent point in the surface distri- 

 bution of density Is the gradation along the 50 fathom (91 m, ) con- 

 tour which runs into the Bay along the coast of Nova Scotia. A 

 distribution such as this clearly points out the import<=nce of the 

 bottom conf igxaration in producing m.lxing in this area. The density 

 distribution at 25 metres (figure 14) has a range from greater than 

 25.8 outside the Bay to less than 23,5 at the head of the Bny. As 

 was found in all other cases the isopycnals at the 25 and 50 m. 

 levels tend to follov/ the general direction of the 50 fathom bottom 

 contour. This is not very marked at 25 m. 



Ill, Discussion 

 The distribution of waters of vorious temperatures and salinities, 

 as found in a given region, is determined by the movements from the 

 various sources of supply. Wind action and tidal movements may be 

 responsible for the piling of waters in certoin areas, but the 

 result<int movements are determined by the prevailing Archimedean 

 and Coriolean forces. The distribution of density tends to bring 



