0. Nortlgaanl. 



jV special characteristic of the ijlaccs above meutioucd is that 

 tlie temperature was below 6° C. and the salinity less than 35 pro 

 mille. There is also reason for supposing that these two factors 

 are more subject to change here than in the fiords mentioned in 

 the former table. For instance, in the Malang Fiord on ^Vi 1899 

 tlie temperature was 4.1 and the salinity 34.67. There are also 

 many smaller fiords, which show similar conditions. Instances of 

 this are tabulated in the following list. 



The fiords above mentioned are certainly connected with those 

 wliich have a bottom temperature of 6° — 7°, and a salinity of about 

 35 0/00, but submarine ridges prevent the warm bottom water from 

 flowing in. Tiie heat which the Gulf Stream brings with it does 



") The N.: 

 ■-) Profess. 



th Atlantic E.xpeditiim, II- 



I- MOHN. 



not exert any influence worth considering on the deeper layers of 

 water in these fiords, and the condition of things in the depths is 

 determined by the local meteorological factors in a special degree. 



A few examples, showing the loss of heat caused -«'here a fiord 

 is shut off by a submarine ridge, will be of interest. On March 

 10th 1899 at a depth of 200 meters in the Ogs Fiord the tem- 

 perature was 1.7 and the salinity 33.40 0/00. On the same day at 

 the same depth in the Vest Fiord outside the temperature 6.7 and 

 the salinity 34.87; there thus being a difi'erence of 5° C. in tem- 

 perature. 



On April 4th HiOU at a depth of 200 meters in the Skjerstad 

 Fiord, the temperature was 3".25 C. and the salinity 33.99 7oo, 

 while in the Salten Fiord the figures were respectively 6°.55 and 

 35.06; there thus being a diiference of 3°.3 in temperature. 



It is not to be wondered at that these ditt'erences evidence 

 themselves in the distribution of fauna. 



As a result of the observations and particulars detailed in the 

 preceding pages it would seem reasonable and natural to divide 

 the northern fiords into two groups') as follows: — 



1. Fiords in which the bottom temperature is a" — 7° C. witli a 

 salinity of about 35 7oo in the water at the bottom. 



(Examples: The Salten, the Folden, the Tys, the Ofot 

 and the Vest Fiord). 



2. Fiords in which the bottom temperature is less than G" C. and 

 the salinity at the same depth is less than 35 °/ou. 



(Examples: The Malang, Lyngen, Kvænang, Porsanger, 

 Tana, Varanger, Skjerstad, Skjomen, Kanstad, Ogs and Kirk 

 Fiords.) 



The Malang Fiord is a kind of connecting link between 

 the two groups. It must also be mentioned that the Skjer.stad 

 Fiord, for instance, belongs to the second group on account of its 

 being shut off by a submarine ridge which prevents the inflow of 

 the ocean water; while the Lyngen and Porsanger Fiords for in- 

 stance, on the other hand, must clas.sify under the second group 

 on account of their being situated so far north that -the ocean 

 water has been considerably cooled and their salinity has been 

 reduced by mixing with fresh water. 



Later on we shall show that the distribution of fauna and its 

 character in the two groups are so ditt'erent. tiiat the above classi- 

 fication of the fiords is justifiable also for that leason. 



1) Cf. Nordgaard: Some Hydrographical Results. (Bergeus museum 

 bog 1899, p. 23). 



