On 25 March, the center of a cyclone was situated northeast of Severnaya Zemlya (pressure: 

 on the Island of Domasch 992. 6 mb, on Cape Cheliuskin 1000.3 mb). A storm with a force up to 

 eight points was located over the northeastern part of the Cheliuskin Sea. As a result, the fast ice 

 (thickness 73 to 78 cm) was broken up at Cape Cheliuskin. 



On the basis of the cited cases, it follows that the break-up of durable fast ice at shores, 

 open to the sea, may occur at any time during the winter under appropriate meteorological con- 

 ditions in spite of the great strength of floating and fast ice. 



I consider that all these phenomena result from waves generated in the ice cover as the re- 

 sult of the storm. The waves are propagated in the water masses under the ice. The ice cover 

 bends in conformity with the form and velocity of the propagation of these "water" waves. This 

 ice cover is only a thin, partly plastic and partly brittle film, which is bent at some places, ac- 

 cording to the form of the water wave, while at other places it is broken open. 



The most interesting phenomena are, of course, those during the storm, 26 to 28 January 

 1943, when the fast ice at Cape Cheliuskin was gradually broken open. A hugh wave rolled in Tiksi 

 Bay, in spite of the fact that the entire sea was covered by solid 9-10 ice with a thickness of more 

 than a meter. This wave recalls the phenomenon called "sea bar" by the fishermen of the German 

 Baltic. 



A roller, with a height of 1 to 2 m, appears on the surface of the calm sea, accompanied in 

 various cases by smaller waves. This roller approaches and breaks on the shore with foam and 

 spray. A special investigation affirmed that the sea bar was caused by a sharp change in the 

 atmospheric pressure, sometimes in distant regions of the Baltic Sea. It is also known that the 

 sea surge formed as a result of storms can cover large distances. Thus, e.g. , on 1 March 1886, 

 an unusual surge with a length of 400 m and a velocity of propagation of 25 m/sec, was noted at 

 the Island of Voznesenie. This surge occurred on 25 February in the region (40° north, 55° east) 

 and covered 3, 640 miles in 100 hours. 



It is clear that the ice cover softens these phenomena and that a combination of various cir- 

 cumstances is necessary for their distinct development. With the exception of the enumerated 

 cases, observations of this type are unknown to me. Thus conclusions are not possible. 



LITERATURE: 62, 77. 



Section 97. Theoretical Concept of Ice Heaping 



The dynamic deformation of ice cover appeared most intense in ice heaping ("hummocking"). 



Hummocking is a complex process. It may be caused by various factors and occurs differ- 

 ently in ices of different thickness and durability. Thus, it is difficult to sum up the theoretical 

 basis of the process of hummocking. Moreover, it is necessary to examine only the first step in 

 this respect. 



In order to simplify the considerations, I assiune that at the time of hummocking, neither 

 thawing nor accretion by freezing occurs, and that the ice appears absolutely as an inealstic body; 

 in other words, only residual deformations are created within it. 



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