Under arctic conditions such a coastal poljmya may last the whole summer until freezing 

 commences in spite of the large amount of ice in the sea. If the water is shallow and with strong 

 wind pressure from the sea, huge ice blocks (nesiak) which sit deep in the water and stay close to 

 the shallows check the pressure of the sea ice on the shore. Littoral islands perform the same 

 function. Thus, navigation becomes a possibility in certain regions for shallow-draft boats close to 

 the shore. 



After the fresh water flows off under the ice and the ice dries due to its rising above sea 

 level the thawing process goes on, as before, in most intensive fashion. This is especially true of 

 the edges of ice which are adjacent to ponds of fresh and salt water and on the southern slopes of the 

 individual heaped-up accumulations. 



In the water puddles on the ice, where the intensive accumulation of solar heat occurs, the 

 melting of ice or contact with the warmer water is hastened by its continuous movement. Water 

 movements are caused partly by the wind, partly by unequal heating and cooling. 



Burke remarks that the characteristic peculiarity of melting of flat type floes (smorosi), 

 consisting of compressed and frozen together grated ice and finely broken ice, is their rapid break- 

 ing apart into separate pieces. Due to this, formation of snow puddles does not occur on ice fields 

 of flat type floes. The water oozes through the thickness of the flat type floes and runs off under 

 them. The entire floe becomes very rotten, although not watery, and is easily cracked through by 

 a ship. 



LITERATURE: 3, 11, 23, 62, 77, 88, 104. 



Section 111. Circulation of Water Caused by Ice 



In order to represent more clearly the movement in the water adjacent to and touching the 

 melting ice, let us suppose that an individual floe is floating in the sea. The sea water directly 

 adjacent to the ice is slightly cooled and freshened (made less saline) by mixing with the thaw water. 

 In the process of cooling and becoming less saline the water density either decreases or increases, 

 depending on its salinity. 



Figure 109. Circulation set up in water in contact with ice. 



As a result of the change in density of the water directly adjacent to the ice a circulation is 

 always set up, as has been corroborated by the experiments of Petterson and Sandstrom. This is 

 indicated by arrows in figure 109. Thus, every ice chunk floating in the water acts as a sort of 

 automatic pump which pulls to the ice chunk constantly changing water masses and thus, by this 

 very act hastens the melting process. As a result, of this process "cornices" are formed above 

 the waterline of every ice floe. These gradually break off and fall into the water. 



303 



