348 PETTERSSON, SIBERJAN SEA. 



upon thc sea to tbe nortli and especially to the east. Accord- 

 ing to the Norwegian observations in July, August and Sep- 

 tember, 1870, the sea-water along the west coast of Wajgatch 

 and also in the south-eastern part of the Kära Sea had a hroivn 

 colour and possessed an exceedingly high tempercdure ' (^r 9° C 

 to + IT G). This superficial layer of warm water together 

 with the frequent rain-fall and the thunder-storms, which often 

 occur here in suramer, must have the effect of accelerating 

 the melting of the ice and the opening of the southern en- 

 trances of the Kära Sea to navigation. Ordinarily the Yugor 

 strait seems to be more free from ice than the Kära strait. 

 The cause of this can be twofold : 



1) The Yugor strait is, according to its situation, more 

 exposed to the influence of the river water from the coast; 



2) There is no under-current of cold water at the bottom 

 of this strait, which could tend to neutrahze the heat of the 

 superficial stratum of warm water. 



The high temperature of the sea, found by the Vega- 

 expedition the 29"' and 30*'^ of July, 1878, may thus be due to 

 a superficial layer of warm water, which occasionally over- 

 flows - the cold water emerging from the Kära strait. A single 

 deep-sounding would have sufficed to settle this question! 



From the Matochkin strait we have discrepant statements. -^ 



1 See the map: >Die Temperatarverhältnisse im Karischen Meere im 

 Sommer 1870.» Geogr. Mitth. 1871. 



•^ In the Yugor Shar the surface current chauges its direction with 

 the winds and the tides. According to the statements of Swethsh and 

 Norwegian travellers the same observation is due also to tlie Kära strait. 

 Krusenstern, however, in 1860 and Ssidoroff in 18G9 found that tliC ^Yater 

 in this strait flowed steadily from west to east. 



Russische Nordpolar-Forschungen 1869 & 1870. Geogr. Mitth. 1870. 



^ Tlie Swedish expedition in 1875 fonnd: 

 Western entrance to the Matochkin, Middle part of the strait, 



13"' July. 8"' Sept. 



Depth. Temperature. Depth. Temperature. 



O m. +6°.i C O m. + 6'.o C 



21.3 m. +4°. 2 C 12.4 m. + .5'.5 C 



23.1 m. + 4". 2 C 



From these observations Nordenskiöld conckided (,in accordance with 

 former investigators), ^4hat a warm stream, probably a branch of the Gulf- 

 stream, fills the entire depth of this sound;'^. In the report of the Holland 

 expedition in 1881, however, we read the following lines (page 63): >Wij 

 namen eene temperatuurwaarneming op verschillende diepten [in the Ma- 

 tochkin strait near the hut of Rosmyslow]. Wij kregen daarmede geheel 

 andere uitkomsten dan Nordenskiöld in 1875 aan bord van de Proven 

 gevonden had. Op den bodeni (37 vaam) was de temperatur nu — 0°.9, op 



