Hydrography. 



15 



Thus -4 .S. ir. so 



- , N. V. so 



111. ■"!..") I max. I 



.ludying- IVom tlie liirui'es just uotcd for ■* i S. .\ll. it iiuiy also 

 hv concluded that the maximum lies between 50 and loo in. Hut 

 this again shows that the changes in temperature take place veiy 

 slowly. In the ISalten Fiord, where the ocean water has free access, 

 there was no sig-n of the maximum at a depth of 80 ni., the autumn 

 maximum had entirely disappeared and the hiirhest temperature was 

 reached at the bottom at a depth of 320 ni. 



.See the foIlo\\iiii;- table. 



1900. The .Salten Fiord 11. 



If the above table be compared to that of the section S. XII 

 (^.4), a striking- difference will at once be noticed. Not only is the 

 bottom temperature in the .Salten Fiord much higher than in the 

 Skjerstad Fiord (.3°.5 difference) but the salinity on the surface of 

 the former is even a little higher than at the depth of 500 m. in 

 .S. Xll. That such decided differences in the hydrographical con- 

 ditions of the Salten and Skjerstad Fiords, as shown by tempera- 

 ture and salinity, also cause biological differences, is a foregone 

 conclusion. This subject will be dealt \\-ith further on in this 

 treatise. 



From the Folden Fiord, 1 have only one sounding (74 1900 

 Foldenfj. I; taken halfway between Hjerto and the south mainland. 

 The depth was 5-30 meters. From the hig-h temperature and sali- 

 nity of the water from the bottom (Vide no. 1067—1078) one 

 may conclude that the ocean water is not prevented from floning 

 into, at any rate, the outer part of the fiord. It should be added 

 that there is another Norwegian fiord which bears the name of 

 the Folden Fiord, it is in the county of North Trondhjem, just 

 south of the 65th degree of latitude. In the old days, the Kristi- 

 ania Fiord also used to be known by this name. 



The Ox Sound and the Sag Fiord. 



One of the entrances to the Sag Fiord from the Vest Fiord 

 is formed by the Ox Sound (between Hammero and LundO). 



While in the sea chart for that part of the Vest Fiord which 

 is beyond the Ox Sound the depth is given as 211—252 fathoms 

 (397.21—474.38 m.) we took in the Ox Sound the following depths 

 from the mouth inwards: 455, 450, 630, 620, 620 meters. So 

 that this short, narrow sound (the length is about 5 miles, and 

 the breadth about 1 mile) has a maximum depth of 630 meters. I 

 believe this is the one single case in the whole of Norway. 



Respecting temperature and salinity, attention is drawn to the 

 tables (nr. 351—362). 



It will be seen that it is especially from the upper 20 meters 

 that the accumulation of the summer heat is given off to the atmos- 

 phere. It may probably also be stated as a fact that the less salt 

 surface layers serve as an isolating belt, by means of which the 

 loss of heat fi-om the layers beneath is to a great extent prevented. 



In the Sag Fiord proper, only a couple of soundings were 

 taken in the inner end outside Furrunes (Sagfj. I, II). The depths 

 here were respectively 210 and 315 m. From the high temperature 

 and salinity of the water at the bottom {Vkh nr. 363—368) I 

 conclude that this inner part of the fiord is not shut off by any 

 ridge from the rest of it. 



The innermost parts of the Vest l''iord and of tJie Tys Fiord 

 are very interesting on account of their great depths. The greatest 

 depth in the Vest Fiord is found north of TranO, for the sake of 

 brevity 1 refer to this as the Trani3 deep (Tranodybet). On the 

 old sea charts soundings are not marked beyond a line Kjeo- 

 Trano, but I have taken many soundings from here, from which it 

 is made clear that the great fall of 5—600 m. and more contiines 

 almost up to Baro. 



Halfway between liani and Rotvær 280 m. were sounded, from 

 here in the direction of Tranii the following depths were noted: 

 324, 570, 608, 610, 630, 620, 535. In a straight line across the fiord 

 from Offerso in the direction of Tiltvigtind the following were sound- 

 ed: 250, 630, 680, 640 m. and from Offerso to the mouth of the 

 Tys Fiord: 485, 580, 585, 320, 465 m. Thus it will be seen 

 that there is a rise directly outside the mouth of the Tys Fiord. 



After this rise there is again a fall in the bed of the Tys 

 Fiord, for soundings taken in a straight line from the centi'c of the 

 mouth of the Tys Fiord to the inner half of Skårberget gave the 

 following figures: 615, 630, 615, 725, 725 m. This great depth 

 is almost without variation right up to Skårberg. 



As far as I knoAv, 725 m. is the greatest depth reached in 

 any fiord north of Trondhjem, and I take the Uberty of calling 

 the great basin which stretches from Korsnes to Skårberg, the 

 Tysfiord deep. The innermost boundary for this basin I am unable 

 to give precisely; the last sounding at 725 m. was taken a little 

 further in than Skårberg, and here dredgiligs ^\-ere made and samples 

 of plankton and water taken (Tysfiord 1). 



A sounding between Ulvo and the Northern mainland gave a 

 depth of 230 m., while tJie depth at the station Tysfiord II, which 

 is a little further in than Tysfiord church, was 409. 



A little further in, in the same arm of the fiord, the bottom 

 was reached at 130 and 140 m. respectively. 



That there is no high submarine ridge between Tys Fioi'd 

 church and the mouth of the fiord, may be seen by comparing 

 the observations made at the two stations {Vide nrs. 651 — 672). 

 The observations made in the basins of the Tys Fiord and Tranii 

 show a great similarity. There is reason to believe that the bot- 

 tom temperature at the places mentioned remains for years at 6 — 7, 

 with a salinity of about 35. The animal and plant existences in 

 the basins, thus live in physical conditions of remarkable constancy. 



The Vest Fiord is continued in the Ofot Fiord, which again 

 has several important arms. Of these, the .Skjomen Fiord and 

 the Rom bak Fiord were vi.sited in 1899. 



There is a rise in the bed a little west of Baro, which is 

 again succeeded by a fall towards the Ofot Fiord. Between Baro 

 and Tjelodden 545 m. were reached, and opposite .Skarstad 550. 

 Then there is a rise; for opposite Havnes the depth was 360 

 (Ofoten 1, '/■. 1899) and between Bogen— Ballangen (Ofoten II, 'h. 

 1900) 258 m. There are considerable depths also in the Rombak 



