even though there were no signs of ice thickening. After stopping the ship, he discovered that a 

 singular pillow of deep ice in the form of needles and crystals had accumulated in front of the bow 

 of the icebreaker. Evidently, beneath the solid nilas ice during very low air temperatures (25 - 30° 

 below zero), the water was filled with particles of deep ice in various stages of development. It is 

 possible that the movement of the icebreaker itself served as a peculiar catalyzer which created 

 deep ice. Captain Shtumpf assured me that he observed the same phenomena in the Yenisei Gulf. 



It follows from these observations that in the separate polar regions vertical winter circula- 

 tion can be strong, that when a layer of slight depth is involved in this circulation, the heat released 

 by the water to the atmosphere proves to be sufficient for forming deep-ice nuclei in this case. * 



Unfortunately, it is not always possible to analyze the phenomena causing and accompanying 

 the rise of large masses of deep ice. Often, only the fact itself is noted without attempts at an ex- 

 planation, and meanwhile formation of deep ice can occur under different conditions. 



The formation of deep ice along the interface dividing a highly cooled saline -water layer and 

 the layer flowing over it, of cold highly freshened, water, has been most fully clarified. This 

 phenomenon is particularly noticeable during calm weather when the upper and lower layers, which 

 differ considerably from each other in density, hardly mix. 



On 11 June, 1894, during the expedition on the Fran , Nansen discovered a rind of soft ice 

 3 cm thick at a depth of 2 to 3 m in a polynya, and came to the conclusion that formation of deep ice 

 at the surface of separation between cool sea water of high salinity and almost fresh melt water is 

 a common phenomenon. 



In 1897, Otto Petterson brought to attention the fact that in Skagerrak the rise of ice beams is 

 sometimes observed which are formed at the surface of separation between the surface-freshened 

 layer (having a salinity less than 22 o/oo, a temperature of -0.8°, and a freezing point of -1.2°) 

 and the deeper saline layer (having a salinity of more than 33 o/oo and a temperature of -1.4°). 



In his notes during the drift on the Sedou, Buinitskii notes on 28 July 1938, that he found a 

 thin layer of completely fresh ice on the very "bottom" of a water opening.** After a day, a new 

 crust of ice formed in place of the one removed from the bottom of the maina . *** 



On 25 July 1939, in the maina across which they were making hydrographic observations on 

 the Sedou , an ice rind consisting of two layers 2 and 4 cm thick, was discovered at a depth of 

 2.5 m. Separate pieces of ice were completely fresh. 



Phenomena of the same sort were observed at the start of winter near the mouths of rivers 

 emptying into the sea, especially near the mouths of rivers flowing south to north. Cold, fresh 

 water flowing onto the surface of the cold sea, is cooled from below, sometimes causing formation 

 of deep ice. 



LITERATURE: 62, 77, 107, 128, 164, 179. 



*0n my request, Evdenov tried several times to repeat the Wright and Priestley observation 

 during the drift of the Sadko in the Laptev Sea during the winter of 1937, but his results were 

 negative . 



** Promo i - An opening in the ice made by currents; a lead eroded by currents. 



*** Maina - A local term for p o 1 yn ya ■ 



102 



