336 PETTERSSOK, SIBEItlAN SEA. 



The influence of the Yenisei river announces itself still 

 more clearly b}^ the diminishing saltness of the water. On 

 both sides of the Sibiriakoff island the saltness was found 

 to be only O.49 p. c. while the sea-water a few miles further 

 to the west, which consists of the outflow from the Gulf of 

 Obi, contaiiis three times as much. In accordance with this 

 fact we find, that also in the North, at 74.3o Lat., the saltness 

 increases and the temperature diminishes the more we ap- 

 proach the west side of the Kära Sea and vice versa. See 

 section XI, which is based upon the observations from 1875 

 together with those from 1878. The fresh and warm water 

 from the Yenisei thus surging up to the east against the 

 Taimur coast naturally makes the level of the sea stånd 

 higher in summer at this shore, on account of the higher 

 temperature and greater spec. volume of the water. This 

 difference of niveau, together with the reaction from the coast 

 upon the flowing water, makes its uppermost layers ^ take a 

 westerly direction towards Novaya Zemlya, where its influence 

 is felt by the diminution of the saltness - and the melting of 

 the ice-floes, formed during winter in this part of the sea. 

 The melting of the ice, which requires an incessant supply 

 of warm water, can not however be completed before late in 

 the summer, in August or September, when the current from 

 the river system of the Obi and Yenisei has had due time to 

 develop its full vigor and direct all the resources of solar 

 heat stored up in its waters to a successfull attack upon the 

 ice of the western basin of the Kära Sea. Until then the warm 

 water current, instead of clearing the sea from ice and open- 

 ing navigable water, will have the contrary effect, viz. to 

 barricade the eastern entrance to the Matochkin Schar by 

 pressing the rest of the pack ice against the coast of Novaya 

 Zemlya. 



The intensity of the surface current, just spöken of, is 

 sufficiently attested by the fact, that the yacht Proven, be- 

 longing to the first Swedish expedition, in 1875, on its return 

 from Port Dickson, the 21**^ August, was driven from its course 

 from 74° O' Lat. 71° O' Long. to 75° 14' Lat. 68° 45' Long., i. e. 

 more than one degree northward and two degrees westward 



^ The pressure of which is not, hke that of the deeper ones. equilibrated 

 by the adjacent water strata and consequently must overflow. 



•2 The saltness at the surface in this part of the sea varies between 

 2.30 p. c. and 3.04 p. c. (see the map, plate 24). 



