much, that it caused the concept of the so-called great Siberian polynya, which has been observed 

 during sled trips from the region north of the New Siberian Islands to the region north of the shores 

 of the Kolyma region. We will return to the question of this polynya in the future. 



The fast ice of the arctic seas of the Soviet Union can basically be considered of year-old 

 duration. Only in exceptional years are the separate bays and straits not open here. In some of 

 the American regions of the Arctic Basin, old fast ice is found. Such fast ice is particularly char- 

 acteristic of the northern fjords of Greenland, where it forms between glaciers falling into the 

 fjords and the exits from the fjords, and which thus block the exit from the fjord by icebergs 

 broken loose from the glacier. Koch called such old fast ice sikussak, which means old ice in 

 Eskimo. 



Old fast ice, which ordinarily contains several hundred ice-bergs, borne by this glacier, is 

 formed opposite a small glacier in the Northern Hemisphere, called the Humboldt Glacier (on the 

 northwestern shore of Greenland, which extends for 100 km along the shoreline. ) 



Every 20 to 25 years, this old fast ice breaks up, and only then are the masses of icebergs, 

 imprisoned until then, able to move toward Davis Strait. 



LITERATURE: 62, 77, 88, 133, 171. 



Section 48. Floating Ice 



Floating ice consists of an accumulation of separate floes and fields which had formed either 

 in the sea itself or as a result of fast ice, old ice, or glacier ice. Therefore, ice of the most 

 variated source and age can be found in the midst of floating ice. In the seas of the Soviet Arctic, 

 year-old ice is predominant, but in higher latitudes, old ice is predominant. 



Pack ice, due to the effect of currents, tidal phenomena, and also wind, is in a state of con- 

 stant motion in both winter and summer. Due to this constant motion in different directions (mainly 

 caused by the action of the wind), the separate floes comprising the pack constantly change their 

 form and contours. 



As we shall see further, the velocity of the movement of the separate floes is different, de- 

 pending on the current or the wind. As a result, the floes which drift faster overtake the slower 

 ones and later drift together at a certain average velocity. The belts are accumulations which form 

 in their turn, overtake the accumulations, which drift more slowly. In this manner, ice fields are 

 formed which are characteristic of pack ice. 



When such an ice field presses against the shore or against immovable ice, hummocktng 

 occurs, both along the line of contact and within the ice field itself. First of all, the young and 

 therefore the weakest parts of the ice field undergo destruction. Simultaneously, there is a de- 

 crease in the area of the field due to the hummocking. 



When the wind changes direction, the ice field breaks loose from the shore or fast ice and 

 begins to move in the corresponding direction until there is a new change in the wind or imtil it 

 again presses against the shore fast ice. 



115 



