I04 FRIDTJOF NANSEN. M.-N. Kl. 



that was observed at Stat, 18 (80° 2' N.) at 210 metres (with 18.2° C, 

 39.91 0/00, and 7.14 cc), and at Stat. 42 {80° 26' N.) at 300 metres (1.87 C, 

 34-92 %o, and 7.22 cc). 



This kind of water may probably be carried down to considerable 

 depths by the vertical circulation during the winter in regions of the sea 

 where conditions similar to those observed between 100 and 540 metres, 

 at Stat. 43, also exist in the upper layers near the sea-surface, and the 

 sea is not covered by ice, but has surface-temperatures above 1.5° C. in 

 the winter. This water sinks to form extensive intermediate layers, with 

 temperatures between 1° und 2° C. and salinities about 349 %o> ^nd is 

 also carried in under the warmer water of the Atlantic Current (containing 

 less oxygen) by the slant convection currents, that occur so universally in 

 the sea [cf. Nansen, 1913, p. 19]. It is thus formed in the same manner 

 as the underlying cold deep-water with much the same salinity, but with 

 lower temperatures, mostly below o*^ C. 



As it was winter and little phyto-plankton when this water was near 

 the sea-surface, its amount of oxygen was probably not very great, though 

 it may certainl}- have been a good deal more than 7.35 cc. per liter, given 

 by our observation at 100 metres, at Stat. 43. hi the course of time the 

 amount of oxygen is, however, gradually reduced by the animal plankton, 

 and also by the oxidation occurring during the decomposition of the 

 dead plankton sinking from above. In the same manner the amount of 

 oxygen of the underlying colder deep-water is evidently also gradually 

 diminished, and therefore we find that the amount of oxygen is decreasing 

 very regularly with increasing depth in these intermediate and deep layers ; 

 and we found that the water of the typical deep-water, observed at Stat. 57 

 at 700 metres, had only 6.96 cc. of oxygen per liter. 



According to our Table III, the minimum of oxygen given by our 

 observations was 6.23 cc, found at Stat. 19 at 510 metres, where the 

 degree of saturation was 80.0 "J/o. It seems strange that the amount of 

 oxygen should be so much smaller here than at 540 metres at Stat. 43 

 only a very short distance off, where it was 7.12 cc. (and 91.8%), although 

 the water seems to have been of the same kind at both places, with the 

 same salinity (34.920/0^1 and similar temperatures (1.29° C. and 1.5 i°C.). 

 At Stat. 57, at 500 metres, the water was also of exactly the same nature, 

 with 1.22*^ C. and 34.92 %o> but the amount of oxygen found was still 

 greater, 7.23 cc. (92 6 %). These discrepancies may be due to errors 

 in our results, and Mr. Gaarder, who made the determinations of oxygen, 

 thinks it possible that 6.23 cc. for Stat. 19 (510 metres) is a slip of the 

 pen for 7.23 cc. But unfortunately he cannot find the original journal 



