Thus, the significance of the continental runoff into the Laptev Sea is increased on account of 

 the heat discharged by the Lena River. 



7. The quantity of heat brought by rivers into the sea is subjected to considerable seasonal 

 fluctuations. Indeed, the entire heat discharged by rivers flows into the sea during the five summer 

 months . During the summer season the heat discharge is also variable . This can be seen from 

 table 19 (after Antonov). 



TABLE 19. HEAT AMOUNT (BY MONTHS) BROUGHT BY RIVERS INTO THE KARA SEA 



Antonov directs our attention to the fact that approximately half of the whole heat of the Kara 

 rivers is discharged during a single month, July. This heat is spent, on the one hand, on direct 

 destruction of ice and, on the other hand, for the warming of atmosphere and the subsequent melting of 

 ice . It is not difficult to see that the heat discharged by the Kara rivers could melt approximately 

 60, 000 km2 of ice with the average thickness of 2m. 



8. The annual runoff as well as the amount of heat discharged by the rivers, does not remain 

 constant from year to year. Table 20 presents the calculation of annual discharges of the Genisey 

 River at the Town of Igarka, on the Ob' River at the town of Salekhard, and of the Lena River at the 

 town Kyiisjrur . 



TABLE 20. ANNUAL VARIATION IN THE DISCHARGE OF THE OB' 

 GENISEY AND LENA (IN KM^) 



By comparing the value of the continental runoff vnth the ice conditions in the Kara Sea, 

 Lebedev arrived at the conclusion that the intensification of river influx is associated with improve- 

 ment of ice conditions. 



9. The river influx dilutes the sea water to a degree. This influence progresses to a rather 

 great distance. Thus, for instance, with a few exceptions, the salinity of surface waters in the en- 

 tire southwestern part of the Kara Sea, which is bounded to the north by a meandering line from 

 mys Zhelaniya across Ostrov Uyedlneniya to Severnaya Zemlya with tongues reaching into areas in- 

 fluenced by the corresponding currents, is lower than 30 o/oo. 



54 



