1903J Studier over naturforholdene i vestlandske fjorde. 45 



maxima and minima of temperature. It has been founcl that there 

 is a difference in their velocity in the two fiords, the By and Hjelte 

 Mords. 



On pages 27 and 28 proofs of this fact are mentioned. Gene- 

 rally speaking, it may be said that at the sea coast, as well as in 

 the fiords, or parts of fiords, which lie very near the coast, it is 

 especially noticeable that the minimum, in the spring, and the maxi- 

 mum, in the autumn, move witli greater velocity downwards through 

 the layers of water than is the case in the inner parts of the fiords. 

 There is also a connection between this and the lower salinity of 

 the surface in the inner parts of the fiords. When the surface 

 water is very fresh, the vertical current will only be slightly distri- 

 buted, so that the heat wave towards the bottom will chiefly be set 

 in motion by conduction, which causes the distribution of heat to 

 take place more slowly than when it is due to the vertical current. 



The greatly mixed water will thus be a very much less sensitive 

 instrument for registering at the bottom the various atmospherical 

 changes in temperature, and the latter will not be traceable so far 

 down as they are at places where there is only a slight difference 

 in the salinity of the bottom and surface layers. It used to be 

 considered that the animal variations in the temperature of the 

 atmosphere had no effect at a depth of about 200 m., but recent 

 investigations have proved that the depth s, at which the animal 

 atmospheric changes exercise an influence, are varying. 



In the Hjelte Fiord, even at a depth of 250 m. the temperature 

 has been found to be subject to variations, but in the By Fiord, 

 at a depth of 150 to 200 m., it has been fairly constant; and in 

 the Mo Fiord the fixed limit is reached at a depth of only 80 m. 

 (cf. this with Pis. I, II and III). 



Temperature and salinity in the deep channels and basins of the 



western flor s. 



Quite an unusual stability of natural conditions seems to prevail 

 in the deep channels of the western fiords. 



A considerable number of observations have been made in the 

 By Fiord (st. A), and from these it is plainly seen that there are 

 only slight variations in the course of several years in the fiord. 

 (Cf. p. 30). 



The same may also be said of the Oster Fiord. (Cf. p. 31). 



