BIGELOW: COAST WATER EXPLORATION OF 1913. 255 



Admiralty (1903) there is a northerly drift into the east side of the 

 Gulf of Maine ; and our own records of salinity show that an indraught 

 of comparatively saline water does take place more or less constantly 

 into the eastern side of the Gulf. But it must be slow, or intermit- 

 tent, for Dawson's (1905) measurements of currents failed to show 

 any dominant drift along the west coast of Nova Scotia. And the 

 organisms which it carries with it are good evidence that Gulf Stream 

 as well as St. Lawrence water enters into its makeup. In short, it is 

 extremely doubtful whether the Cabot Current can be traced, as an 

 observable or measurable drift beyond Nova Scotia. Consequently 

 the southwesterly currents noted south of New York (p. 230) require 

 some other explanation. 



In 1907, Pettersson offered a totally different explanation for our 

 cold coast water, namely, that it was not northern water flowing 

 southward, but water welling up from the Atlantic abyss. And 

 although few, if any oceanographers have adopted this view in its 

 entirety, both Schott (1912) and Krlimmel (1911) beUeve that there 

 is more or less upwelling along our coast, particularly in winter. 

 And Clark (1914) maii|tains that the cold water off Nova Scotia must 

 be abyssal in part, to account for the distribution of crinoids. 



Upwelling, whether on a large or a small scale, must obviously 

 largely depend on the pre\'ailing direction of the wind; consequently 

 along our coast, where off shore winds prevail in winter, winds parallel 

 to the coast in summer, it might be expected to be seasonal. And 

 for this reason our data for 1913 can only be expected to show its pres- 

 ence or absence in summer. But they are worth analyzing, because 

 the occurrence of upwelling in this region has so far been deduced 

 from theoretical grounds, rather than from actual observation, previous 

 knowledge of subsurface salinity on the continental shelf being practi- 

 cally nil. If abyssal water had been flowing up the continental slope 

 in any considerable amount at the time of our voyage, salinity and 

 temperature would necessarily reveal its presence, just as they do in 

 parts of the oceans where there is a well-marked updraught of bottom 

 water, next the coast. Perhaps as useful an index as any in the warm 

 months, in temperate zones, is surface temperature, for in regions of 

 active upwelling, the constant access of cold water from below retards 

 seasonal warming, and consequently causes the surface to be abnor- 

 mally cold. And unless the updraught should extend along the whole 

 coast line, a most improbable supposition, the cold region would be sur- 

 rounded by warmer surface water, north and south as well as oft" shore, 

 just as it is off the coast of California (McEwen, 1912), and oft' the 



