Hummocking of Ices In the Bering Sea

One of the important elements complicating navigation, the fish craft and extraction of minerals from sea bottom, is an ice cover and, in particular, the hummocking. Hummocking of ice happens under influence of wind, tidal and permanent currents. For Bering sea, where in the winter stationary Aleutskaya depression also goes deep, the prevailing of gales with velocity more than 30 mps and continuous duration exceeding 10 day is characteristic. Therefore primary factor forming hummocking here, is the action of a wind. At the same time, the centre of Aleutskaya depression can be established in area of Kommandor islands - Petropavlovsk- Kamchatskiy, in centre of Aleutskie islands or in east - in Alyaskinskiy bay. In each of these cases the wind flow has a miscellaneous direction. In the first case above Bering sea the southern wind flows, in second - eastern or southeast, and in last - north-east predominate. Under effect of these flows the ice cover accordingly tends to reduction or to expansion of the occupied area. Hummocking of ice also should test a significant interannual variability. In the first authors of paper have a task to construct charts hummocking of ice in the Bering sea for various types of winter (ice-cover) and to give their analysis. By an initial material for construction charts of hummocking of ice were the decade data of the ice airreconnaissances which have been carried out above Bering sea till 1959 to 1989. Extreme and average meanings of ice-cover for all ice period in the beginning were received. From these data the zones with large, average and small ice-cover as 20 % of repeatability from extreme and average meaning were outlined. Further from all number of observations the sample was effected years getting in the elected gradation of ice-cover.