PHYSICAL OCBANOGKAPHY OP THE GULF OF MAINE 



715 



(figs. 15 and 16), they show the water freshest where coldest (i. e., inshore), saltest 

 where warmest — a relationship that prevails all along the North American seaboard, 

 between the latitudes of Chesapeake Bay and of Cape Breton, at the time of year 

 when the temperature is at its lowest. The profiles for salinity differ, however 

 from those for temperature, in cutting across alternate bands of fresher water next 

 the coast, salter in the basin, fresher again over Georges Bank, and saltest of all at 

 their seaward ends outside the edge of the continent. This succession on the west- 

 ern profile (fig. 96) mirrors the expansion of water of low sahnity (32.5 per mille) 



Fig. 96.— Salinity profile running southward from the offing of Casco Bay, across Georges Bank, to the continental slope, Feb- 

 ruary 22 to March 5, 1920 



out from Cape Cod across the western part of Georges Bank. On the eastern 

 profile, however (fig. 97) , the contrast between slightly lower values over Georges 

 Bank (32.6 to 32.7 per mille) than over the basin immediately to the north of it 

 (32.8 per mUle) is associated with the indraft via the Eastern Channel, which 

 interrupts the picture by raising the salinity of the upper stratum of that side of the 

 basin slightly above the values that might otherwise be expected there. In brief, 

 then, the contrast between basin and bank is caused on the one profile by outflow 

 over the latter from inshore, but on the other profile by an inflow around the bank 

 into the gulf. 



The two profiles agree in showing comparatively low and uniform salinities 

 (temperatures, as well) at the offshore ends in the upper stratum, with the curves 

 for the successive values so nearly horizontal there that it would evidently have 



