I92I, 



No. 



THE STRAXDFLAT AND ISOSTASY. 



173 



Fig. 131. Fugle Fjell (Bird Mountain) on the south side of Bear Island. 

 After a photograph by A. Hamberg 1898. [From Nansen 1920]. 



submarine platform 9 to 20 kilometres broad, surrounding Bear Island. 

 A similar submarine platform evidently surrounds Hope Island to the 

 north-east, and on the submarine ridge connecting these two islands the 

 soundings indicate three flat banks at the same level, with depths about 

 30 to 40 metres below the sea surface. 



The question is whether these platforms ought not to be considered 

 as parts of the strandfiat which during times of emergence have been 

 cut down to somewhat lower levels than the Norwegian strandfiat. The 

 probability is that they are built up of rocks with relatively little power 

 of resistance to erosion, like those of Bear Island and Hope Island, and 

 they have, therefore, easily been planed off during periods of emergence, 

 even though these may have been relatively short. 



In my opinion it is impossible that the emerged strandfiat of Bear 

 Island (the northern plain) can have been developed to its present shape 

 during preglacial time, neither by marine denudation nor by subaërial 

 denudation. In the latter case a drainage system would have been 

 developed on the emerged, gently sloping plain. It might be objected 

 that all traces of the broad, shallow valleys of this system have b?en 

 obliterated by later glacial erosion. But if so, this glacial erosion would 

 naturally have dissected the plain and made it more uneven. By whatever 

 process this strandfiat was formed, it is obvious that no preglacial plain. 

 as level as this and cut in rocks with so little power of resistance, could 

 have survived the destructive erosion of the glaciers of the great Ice Age. 



It seems to me probable that this emerged strandfiat was planed off 

 to its present level surface by the shore erosion, as I have previously 

 described, during periods when the island was standing somewhat lower 

 (at least 30 to 50 metres) than now. Before that time the island had been 



