In paper the intraannual and interannual variability of an ice cover in " Sea of Japan", the Sea of Okhotsk and the Bering Sea is considered. The estimation of ice cover distribution, i.e. the sea area, where the ice without consideration of its age, forms and concentration presents, was carried out. The values of the ice volume, generated in the far-eastern seas, are calculated from a point of view of it hummock concentration during a period of maximum ice cover development.
The regular observations of an ice cover in the far-eastern seas of Russia have been fulfilled with the middle of 20 century. In the Sea of Japan they were produced with 1950, in the Okhotsk Sea with 1956 and in the Bering Sea after 1959 for 1991. Observations were carried out by hydrologists for ten-day periods from the specially equipped airplanes. The period of investigations amounted of the beginning of an ice formation up to ultimate purification from the ice. In last decade visual studies have been stopped and also the satellite information has replaced them. Observations were carried out continuously and visually on standard routes at flight of the airplane of the area of ice cover. Flights were made every ten-day period. The saved material of ice cover observations allows estimating an intraannual and interannual variability of an ice cover distribution in three considered seas areas. In the present paper the sea area where the ice without taking into account of its age, forms and concentration is considered as the ice cover distribution value.
In "Sea of Japan" early ice formation occurs in the second middle of October. The first ice appears in the north of the Tatar Strait and in the Sovet Havan Bay.