Hydvdgi-ii 



13 



Till" tompeiiiturc values in tlic uppcM- layers show consklorahlc 

 (Ircrcase. while in the ilei^p a iiroixt eonstaney ]ircvails. P>ul un 

 the other hand, on the Kost Sea the npiier layei's show a coni- 

 jiaratively hig'h temperature. 



At 



hut 

 the 



1.1 (1 



) (leiith of !■_>() uietei's. tin 

 then there is a -real dill' 

 teuiiieratui'e falls from r,.- 

 uit in the Tvs KionI at Ih 



tempeiature at hotli plaecs was 

 lenee het ween them. On the 

 to l.;i het ween 120 and 7(H) 

 same deiiths it only falls from 



What eaii he 



It will at nni 



layers in the sea 



ditl'ereuee is tound 



eo.dini:- of the surf 



stra 



10 reas(m oi th 



he nolieed that the 

 i-e pretty uuudi the sar 

 n the Tys l-'iord. At 

 e iiives rise to vertieal 



dinai'y diHerenee? 

 :iliuity of the ditfcrent 

 ■. w hile a, eonsiderablc 

 the former jilaee. the 

 ■urreuts. wliieh in their 



turn almost halanee the ditt'crcnec in tenii)ci'atuie. 



In this way even a pi'ctty deep layer of water ma,\ exehaiii^e 

 heat with the atmos])hei-e. But when the eondition.s arc like those 

 in the Tys Finril. w here the salinity in the upper layers is so varied, 

 even a consideiahle deercasc of surface temperature will not distui'b 

 the ei|uilihriuui o\' the watei-. 



As niiw the distrihutiim of heat through the water takes place 

 slowly, the result nuist he that the surface itself decreases consider- 

 ahly in temperature, and that it is only a comparatively thin layer 

 which exchang-es heat with the atmosphere. 



So as to get an idea of the extent of the changes which take 

 jilaee in the upper layers, let us examine H. H. Gkan's observations 

 made in the Tys Fiord in the summer of ISDsM {Hydrographical 

 Tables s. XXVII). 



1898. (>8» 1.5'.4 N., 16" "'.3 E. 

 Korsnes in the Tvs Fiord. 



As Gkan's station was close to the place where 1 made my ob- 

 servations (Ty.s Fiord I), the results may be compared. 



We get the impression that the top layers are subject to great 

 increase of temperature in summer and g-reat decrease in winter, 

 and wee see too that the temperature at a depth of 100 meters on 

 the -'7- was 5.4 and 5.5 on the '-'Va- 

 lt is wellknown that the natural conditions in the depths of 

 the large tiords are tirmly established. The water in the deep fiord 

 basins is tolerably homogeneous, the temperature and salinity are 

 almost unvarying throughout the whole mass, and there are only 



1) H. H. Gr.^n. 

 Ocean and the I'oasi 

 Investigations. Vol. 



L.graiihioal, Biol 

 u-dlaiul. (Rejmi- 

 O. Nr. 5). 



Atlantic 

 i Marine 



very slight dilferenees in the course of a year. There are especially 

 two thiu-s which control this. 



In the lii'st place, the topography of the bottom of the .sea is 

 of extreme importance, foi-, if for instance the deep part of the Tys 

 Fiord was lengthened out towards the ocean, the probability is tliat 

 conditi(uis would then be .somewhat different. 



In the .second place, the supply of continental fresh water, 

 A\hich by weakening the surface layers forms these into an isolating 

 belt, is doubtless of great imjjortancc in connection with the stability 

 of the conditions in the depths of the iiords. 



There is certainly every reason to believe that there is a thicker 

 layer on the sea which gives oif heat to the atmo.spherc than in 

 the tioi'ds, but this does not, all the same, explain the great iall 

 in temperature in the deep wliich takes place beyond the .sea boundary. 



One can scarcely think that this is kept up in any other 

 way than by the How of watei- from colder regions. There must 

 1)0 a cold undercurrent in the ocean.') 



b. The Fiords. 



In the winter of 1899, I had an opportunity of visiting sevei'al 

 of the northern fiords, and as I was able to make two sets of 

 observations in some of these, 1 am in a position to give results 

 which make it possible to compare. I was however prevented from 

 making observations in the same fiords during the following wintei-. 

 i)Ut I had the pleasure of obtaining several observations in tlie 

 Skjerstad l'"iord, which presents many pecuUarities on account of 

 its considerable depth and its being so shut otf from the sea. 



In the following pages, some details will first be given of each 

 of the fiords visited, then an attempt will be made to give a gene- 

 ral characteristic, by help of which the similarities and dissimilarities 

 in physical conditions will be made clear. 



Sandhorno (o-island) which is situated S. of Bodo on the south 

 side of the Salten Fiord is separated from the mainland by two 

 .smaller fiord.s. Jietween Gildcskaal and Sandhorno we have Mor s- 

 dal Fiord (also called S. lieier Fiord and Sund F'iord) and on the 

 opposite side Ave have N. ] Jeier Fiord. In these two small fiords 

 di'edgings were made "/a 1900. 



The farm Sund lies at the point of Gildeskaal peninsula. 

 Here dredgings were made at a depth of 50 — 150 meters, and in 

 the adjoining fiord just inside Kvarsnes at a depth of 50 metei's. 

 Neither of the.se tiords seemed to be very deep. 



The Salten Fiord is the tolerably broad fiord arm which 

 runs into the land near Bodii. The islands Stromo and GodO se- 

 parate it from the Skjerstad Fiord, which farther in is also cal- 

 led the Saltdal Fiord. The Salten and the Skjerstad Fiord are con- 

 nected by three comparatively shallow sti-eams, of which the cen- 

 ti'al one, the famous „Saltstrom" is a rival to the Moskensti'om in 

 bulk and force. With regai'd to the depth of the Salten Fiord, 

 two soundings are marked on the sea chart about half A\ay be- 

 tween Sandhorno and the peninsula on which Bodo is situated, the 

 one states a depth of 131 f. (246.60 m.) the other 112 f. (210.84 

 m.). A little further in, 1 sounded .380 meters but it was from a 

 depth of .•i20 m. that the samples of water wei-e taken (Salten- 

 fiord II). 



1) Cf. 



nouniphical Hesnlt.s 

 of 1900. N. Mag. 



