Winter River Runoff on Spitsbergen

I.Yu. Solov’yanova and B. R. Mavlyudov

Despite drying (freezing) rivers in the winter time, the winter runoff on Spitsbergen rivers still existed. It is expressed as extensive naledies (icings or aufeis) in frontal parts of polythermal glaciers. Naledies are widespread phenomena on Spitsbergen. Their formations occur due to a special thermal structure of polythermal glaciers. Maximal observed naled had the area 4–5 km2 , its volume is about 8–10 million m3, and the average winter discharge was equal to 0.42 m3/s. The average density of naled ice is equal to 0.75 g/cm3. The structure of naled ice is various and depends on a place of water outflow ND THE GLACIER VALLEY SIZES. However, there are no data on the intensity of naled ice increase and dates of start and end of its formation. He share of winter river runoff in the annual volume is not essential and makes up about 1–5%.The accuracy of values of winter runoff determination is also low. However, it is necessary to take into account these values in calculation of water balance of river basins.