- No. 2. SPITSBERGEN WATERS. 65 



direction may, at least during some periods, have changed more and more 

 towards the left with increasing depth, while the velocity may perhaps have 

 increased somewhat down to a certain level. Our observations at 50 me- 

 tres, at Stats. 41 a 42 (Table I), indicate great variations in temperature and 

 salinity at this level. On August i8th, at 1.15 a. m., there was observed 

 at 50 metres o.85C. and 34.60 / 00 (density 27.76); at 10.00 a. m. on 

 the following day, at the same depth, there was found 2.21 C. and 34.815 / 00 

 (density = 27.83), at 3.20 p.m. 0.83 C. and 34.650/00 (density = 27.80), 

 and at 5.30 p. m. the temperature was 0.09 C. At 7.40 p. m. at Stat. 42, 

 a few hundred yards outside the ice-edge, we found at 50 metres 2.82C. 

 and 34.71 /oo (density = 27.69). Water of different types was consequently 

 at intervals observed at this depth: a cold water (0.85 C.) with lower 

 salinity (about 34.60 % ) at 1.15 a. m. on August i8th, and at 3.20 p. m. 

 on the following day (at 5.30 p. m. it was still colder) and a much warmer 

 water (2.21 C.) with a higher salinity (34.815 / 00 ) at 10.00 a.m. on Au- 

 gust 1 9th. 



The cold and less saline water may come, more or less, from the ice- 

 regions of the sea to the north or north-west, while the warmer and more 

 saline water must come from the south. It is, however, noteworthy that 

 when the cold water was observed at 50 metres, the water was moving 

 in north-easterly directions, at that level relatively to the ship, while the 

 water was moving westwards, relatively to the ship, when the warmer and 

 more saline water was observed. The changes in the water cannot, there- 

 fore, be adequately explained simply by horizontal movements of the water 

 at this depth; they are more probably due to vertical oscillations of the 

 water-strata, chiefly caused by the changing tidal currents, as will be dis- 

 cussed later. 



We must then assume that between the layer at twenty metres with 

 i.nC. and 34.11 %o an d the layer observed at 50 metres with 2.2iC. 

 and 34.815 / 00 > there was a colder layer with 0.85 C. and 34.60 / 00 , which 

 was sometimes lowered to 50 metres, while at other times the underlying 

 warmer stratum was lifted to that level. 



At 100 metres the water had a more uniform temperature of about 

 2.9C. and a salinity of about 34.96 / 00 ; being the typical waters of the 

 Atlantic Current running towards the north-east in fliis region. 



Our observations show that the currents at all depths are greatly in- 



fluenced by the tidal waves, as was already proved by Helland-Hansen's 



important observations some years ago [1906]. Thus the phenomena be* 



come very complicated, and in order to follow the variations of the direc- 



Vid.-Selsk. Skrifter. I. M.-N. Kl. 1915. No. 2. 5 * 



