CANADIAN FISHERIES EXrEDJTION, VJl'i-lo 373 



Over this channel these cold-water layers are more extended during the summer than 

 in the spring, a circumstance which seems to confirm the idea that there is a constant 

 inflow of colder water through the deeper parts of Belle Isle strait. In Cahot strait 

 we find traces of water layers of negative temperature, a slight minimum occurring 

 in the middle of the strait at a depth of 95-125m., where the salinity is between 32-5 

 and 3)3 "iMi (outer bank water). In the Atlantic ocean, the 10° isotherm rnns mostly 

 horizontally at a depth of 15 to 30m. In the two southernmost sections it very suddenly 

 trends vertically over the edge of the banks, farther north it trends vertically at a 

 distance off the slopes, especially off the mouth of the Laurentian channel. It becomes 

 horizontal again at a depth of 25O-300m. The deeper parts of these warm water- 

 masses (below 20m.) belong- to the Gulf Stream, as shown by the salinity, while tli(^ 

 upper strata seem to be of more continental origin. Off the Laurentian channel the 

 influence of the water from the gulf of St. Lawrence at the surface seems to lie 

 unquestionable, at least as far out as station XVII 74, and the offshoot of relatively 

 fresh water at the surface south of Sable Island bank indicates that similar conditions 

 prevail in this area too. Water having a temperature between and 5i° C. occupies the 

 deeper parts of the Laurentian channel and the channels between the Nova Scotian 

 banks, as was the case in the spring. In the spring \ve found layers of wat6r of 

 negative temperature at least over the'northei'n Xova Scotian banks; in the summer 

 in the Atlantic part of the area investigated these layers are limited to the channels 

 and slopes of the Xewfoundland banks, with slight minima situated over deep water 

 as found at stations XVIII 76 and XX 86 and 87. 



The conditions reviewed above seem to indicate an increase in the influence of 

 the Gulf Stream and of the currents of continental origin, while the influence of the 

 Labrador current seems to have decreased from spring to summer. The water-masses 

 of continental origin have enlarged their area of distribution in a more horizontal 

 direction, occupying the superficial strata, while the Gulf Stream has forced its way 

 close tip to the slopes with w-ater-masses of immense vertical extension. The Labrador 

 (Arctic) current displays its influence in nearly the same areas as in the snring, but 

 the higher temperatures and salinities show that its influence has diminished. The 

 northern branch of the current turns round cape Ray and runs westward along the 

 Xewfoundland coast; the southern branch runs more to the south at right angles to 

 the direction of the Laurentian channel. This latter branch is deflected towards the 

 Xova Scotian banks through contact with water-masses of Atlantic origin. As shown 

 above (p. 369) these conditions are found during the summer as well as in the spring. 

 The water-masses especially characteristic of this current are mostly found ;it a dcntli 

 of 80 to 250m. during the summer, and from about 30m. downwards in the spring!. 

 Though the influence of the Labrador current off the Newfoundland banks seems to 

 have decreased in the summer, the contrary seems to be the case with the branch of 

 the current entering the gulf of St. Lawrence through Belle Isle strait, as shown by the 

 masses of water of negative temperature over the Esquimau channel. I cannot find 

 any other explanation of this fact than aii increased inflow of cold water from the 

 north, and at the same time I take it as an indication that the principal :source of the 

 (layers of excessively cold water in the gulf of St. Lawrence is to be found in the 

 inflowing currents of Arctic water entering the gulf through Belle Isle strait and 

 Cabot strait. 



Before concluding this paper I must express my sincere thanks to Di*. Johan 

 Iljort for his kindness in giving me the opportunity of working out the results of the 

 expedition as regards the hydrographical observations, and also for his suggestions 

 as to the best way of attacking the work, and for his valuable help in the details. 

 My best thanks are also due to Mr. James Chumley, Glasgow, who has revised my 

 manuscript in a masterly manner, and to Messrs. Einar Lea and Thv. Easmussen, 

 Bergen, for valuable help by preparing the figures. 



