PHYSICAL OCEANOGRAPHY 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 Acadia in 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 difficult 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, it is an open question whether this Arctic contribution is 
sufficient to lower the temperature of the coldest stratum of the Gulf of St. Lawrence 
8951—28 53 
