PHYSICAIj OCEANOGKAPI-IY of the gulf of MAINE 829 



unmixed Labrador Current (temperature below —1°) is colder than the coldest 

 outflow from Cabot Strait, or than the coldest water over the Scotian shelf, which 

 have never been found to fall below —0.5° in temperature. The evidence of salin- 

 ity, of like import, is even more instructive in this respect, for the undiluted Labrador 

 Current off the Grand Banks is considerably more saline than the cold water next 

 the Nova Scotian coast, being characterized by a salinity of at least 32.5 per mille, 

 while its surface salinity hardly falls below 32 per mille even along its inner edge, 

 where most influenced by drainage from the land (minimum so far recorded about 

 31.9 per mille; Matthews, 1914). 



"From this," as I have stated elsewhere (Bigelow, 1917, p. 236), "it appears that 

 did any considerable amount of unadulterated Labrador water join the Nova Scotia 

 coast current, the temperature of the latter would be lower, its salinity higher, than 

 in Cabot Straits"; whereas both the temperature and the salinity of the cold band 

 skirting the Nova Scotian coast have proved remarkably uniform, from the straits 

 westward to its farthest extension. It is true that an infusion of Labrador Current 

 water (spreading westward from the Grand Banks region) might join the Nova 

 Scotian coast water without lowering the temperature of the latter did it mix suffi- 

 ciently with the warmer water, which it must needs displace en route, to raise its 

 own temperature by 1° or more. Such a mixture, however, would necessarily raise 

 its salinity as well as its temperature, because the water that normally fills the deep 

 oceanic triangle between the Scotian and Newfoundland Banks is considerably more 

 saline than the Labrador Current, a fact amply demonstrated by repeated profiles 

 run by the Ice Patrol and by the Canadian Fisheries Expedition (Bjerkan, 1919). 

 Hence, if any large amount of such mixed water joined the cold Nova Scotian coast 

 current, the salinity of the latter would be made considerably higher than it actually 

 is, so that salinity would betray the event even if temperature did not. Actually 

 nothing of the sort has been recorded, observations taken by the Grampus, the 

 Canadian Fisheries Expedition, and the Ice Patrol uniting to demonstrate that low 

 salinity is as characteristic of the cold band next Nova Scotia as low temperature is. 

 However, the temperatures and salinities taken by the Acadiam July, 1915 (Bjerkan, 

 1919), make it at least highly probable that isolated offshoots, pinched off as it were 

 from the Labrador Current, do occasionally drift westward as far as the continental 

 slope off Banquereau Bank and Cape Sable. Otherwise it would be diflacult to 

 account for the pool of icy water ( — 1.7°) then reported off Sable Island — a pool 

 both colder and more saline (32.82 to 33.08 per mille) than the outflow from the 

 Gulf of St. Lawrence, but which reproduced the coldest water of the Newfoundland 

 Banks in its physical character. 



These several lines of evidence forbid the possibility that the Labrador Current 

 is directly responsible for the low temperature of the cold water that reaches the 

 Gulf of Maine from the east. Water from the Labrador Current may reach the Gulf 

 of Maine indirectly via the discharge from the Gulf of St. Lawrence, for a certain 

 amount of this Arctic water may enter the latter along the northern side of Cabot 

 Strait. Huntsman's (1925) recent survey of the Straits of Belle Isle points to a 

 greater inflow of Arctic water by this route than Dawson's (1907) earlier survey had 

 suggested; but even so, \i is an open question whether this Arctic contribution is 

 sufficient to lower the temperature of the coldest stratum of the Gulf of St. Lawrence 

 37755—27 21 



