192 1. No. II. 



THE STRANDFLAT AND ISOSTASY. 



45 



Fig. 20. Shore-plane formed at present sea-level, on Ribachi Peninsula. The picture is 

 taken at low water [after W. Ramsay, 1900]. 



the wave erosion on the shore may be much increased horizontaUy. The 

 sea win then get freer access to the shore-ledge. It will gradually raise 

 the level of the disintegration by frost, and the breakers will reach the 

 actual shore with greater force, less energy being expended in deepening 

 the submerged part of the shore-plane. Hence the combined erosion of 

 the frost and the breakers may advance landwards at a greater rate. The 

 result will be a wider but more sloping shore-plane. The effect of the 

 erosion will be extended more horizontally, but the vertical erosion will 

 be less. 



If the coast be slowly emerging during the process, the result will be 

 the opposite. The effect of the combined erosion will be extended less 

 horizontally, and more vertically. It will lower the seaward part of the 

 shore-plane, and the result will also in this case be a more sloping plane, 

 but narrower, standing on the whole at a lower level. 



During those periods when, according to rny view, the Norwegian 

 strandfiat was mainly developed, the sea-level was for a long time fairly 

 stable, or the coast was being quite slowly submerged, owing to the weight 

 of the accumulating ice-caps (cf. infra) . During the periods of emergence 

 of the coast, after the ice-caps had been removed, the land was much sub- 

 merged. Then the raised beaches were formed, while the strandfiat was 

 lying below sea-level. The climatic conditions may then, to a great extent, 

 have been less severe and less favourable for the shore erosion by frost. 



The ability of the shore erosion, described above, to develop a strand- 

 flat along a coast, will depend on the relative length of the shore-line and 

 on the heigth of the land (i. e. the quantity of rock to be removed), not 

 considering the power of resistance of the different kinds of rock. 



Along a relatively undissectcd and high coast the effect of the shore 

 erosion in this respect, will be very little, and unless the rocks be very 



