TABLE 18. THE MEAN ANNUAL DISCHARGES (IN KM^) OF THE MAIN 

 SIBERIAN RIVERS INTO THE ARCTIC BASIN ON THE BASIS 

 OF DATA BY THE ARCTIC INSTITUTE 



River 



Discharge in km^ 



Genisey 



Ob' . . . . 



Discharge of all rivers into the Kara Sea . 



Khatanga 



Anabara 



Olenek 



Lena 



Gana 



Discharge of all rivers into the Laptev Sea 



Indigirka 



Alazeya 



Kolyma 



Discharge of rivers into the East Siberian Sea 

 Discharge into the Kara, Laptev and East 

 Siberian Seas 



663 



583 



1583 



70 



15 



37 



506 



40 



731 



54 



10 



112 



211 



2,525 



Table 18 shows the annual influx in km^, from the main Siberian rivers discharging into the 

 Arctic Basin. It is seen from the table that the discharge of four rivers — Ob', Genisey, Lena and 

 Kolyma — makes up more than 74 per cent of the entire continental runoff. 



2. The rivers that discharge their waters into the seas of the Soviet Arctic flow in a south to 

 north direction. Therefore, their waters heat the adjacent sea areas. The mean temperature of 

 influx into the Kara Sea equals 6.0°, into the Laptev Sea 8.8°, into the East Siberian Sea 8.3°. 



3. Due also to this fact, ice in the river estuaries breaks up before the breakup occurs in 

 the adjacent seas; this breakup occurs partly under the impact of high water progressing from 

 south to north (dynamic action) and partly because of high temperatures of fluvial waters (thermal 

 action). Because the melting in the arctic progresses always from fresh water areas, which are 

 formed by different causes, the river estuaries are usually the centers of initial ice melting. 



4. Diluted waters, especially in the shallows, freeze over before the more saline sea water. 

 Therefore, river estuaries are the initial centers from which ice formation progresses into adja- 

 cent areas. 



5. The sharply pronounced seasonal character of continental runoff demands our attention. 

 This season character is explained by the fact that all of the rivers run over permanently frozen 

 ground. As a consequence, these rivers are not fed by the ground water. In addition, small 

 rivers that flow over the tundra freeze to the bottom over rifts. Thus, for instance, more than 



90 per cent of the entire annual discharge of the Gana River enters the Arctic Ocean during the 3.5 

 summer months (without ice). 



6. The quantity of continental runoff does not determine the amount of heat brought into the 

 sea by rivers. The heat amovmt, expressed in kg-cal (multiplied by lO-'-^), which is discharged by 

 rivers annually into the Soviet Arctic seas is according to Antonov and Zotin, as follows: 9500 for 

 the Kara Sea, 6400 for the Laptev Sea and 1750 for the East Siberian Sea.* 



♦These figures are roxmded off. 



53 



