220 FF^IDTJOF NANSEN. M.-N. Kl. 



on Storfl, ]Krlia|)s soniiuliat lii.L;licr lliaii in olhcr rej^ionsj. J ii iiortlicrn 

 Norway, especially in J lelj^elaml, this level is ]K-rlia])S somewhat lower, 

 and is less conspiciujus. 



A lower level which in southern Norway is about 15 to iS metres 

 above the sea (in the inner j)art of Sogne i^'jrjrfJ about 10 anrl 12 metres) 

 and in Plelgeland in ncjrthern Norway is somewhat lower, about 8 to 10 

 metres (or even 5 metres), and is there of wide extent. 



A submerged level which is not niucli developed along the coast of 

 southern Norway, is much more developed along the coast of Søndmør, 

 Romsdal, and Nordmor coast, and is of a very wide extent along the coast 

 of Helgeland. Wherever this level is well developed it has a depth of 

 only some few metres, and less than 10 metres, l)e!ow present sea-level. 



These different levels of the strandfiat obviously indicate that the 

 shore-line has stood at different levels during the long periods when the 

 strandfiat was developed. We must assume either tliat the land has risen 

 or that the sea-level has been lowered. 



The inner part of the emerged strandfiat (at the upper level) has 

 obviously been formed at some earlier period than the lower part of the 

 strandfiat (at the lower level). When the submerged level was formed 

 is more difficult to decide. We have seen that in Helgeland where this 

 level is especially well developed and is of very wide extent, it is only 

 some few inetres below the lower level of the emerged strandfiat, and it 

 might almost seem doubtful whether, in this region, it has not been 

 formed more or less during the same long period as the latter. 



In Spitsbergen we have found a well developed emerged strandfiat 

 with heights above sea-level very similar to those of the Norwegian strand- 

 flat, and there is also a distinct submerged strandfiat with a depth of less 

 than 20 metres. 



On Bear Island there seems to be a wider range between the upper 

 limit of the emerged strandfiat and the level of the submerged strandfiat, 

 but this may be due to special reasons as has been previously mentioned. 

 In other regions, especially Arctic, where there is a well developed strand- 

 flat, the investigations are not sufficiently detailed to give definite in- 

 formation about the heights of the levels, but they seem to be somewhat 

 similar to the heights we have found in Norway and in Spitsbergen. 



Causes of the Changes in the Level of the Strandflat. 



It is, in my opinion, probable that the different levels of the strand- 

 flat in Norway indicate different interglacial periods of its formation, 

 and mark the levels of equilibrium of the land crust during each of these 

 periods. 



Owing to the great quantities of rock and the débris of the inter- 

 glacial erosion carried away from the land-surface into the sea by the big 



