154 



PHYSIOGRAPHY 



Where waves cut in upon the land along their shores they make 

 steep slopes, or cliffs (Fig. 2, PI. XL, p. 144). Such cliffs on the sea- 

 shore are called sea cliffs, and those on the shores of lakes may be 

 called lake cliffs. Cliffs along shores indicate that the waves are 

 now cutting into the land, or that they have recently done so. 

 Slumping often accompanies wave erosion. 



The cliff developed by wave-cutting is often bordered by a 

 wave-cut terrace a little below the surface of the water (Fig. 155). 

 The width of this terrace is a rough sort of measure of the advance 



Fig. 155. Diagram of a high sea cliff. It shows also a submerged terrace, 

 due partly to wave cutting, and partly to building. 



of the water on the land by the cutting of its waves. By rise 

 of the land, or by sinking of the sea, the terrace may become land 

 (Fig. 156). 



Fig. 156. Wave-cut terraces now well above the sea. Either the land 

 has been raised or the sea-level has sunk since the terraces were cut. 

 Seward Peninsula, Alaska. 



