4 o 



ALASKA GLACIERS 



The western part is partly concealed by a timbered ridge 

 running parallel to the coast (fig. 20). This ridge, which 

 is probably a huge moraine of Pleistocene age, extends 

 westward far beyond the end of the glacier. Our landing 

 (June 1 8) was at the western end of the ice cliff, coincid- 

 ing with the eastern limit of the timbered ridge. 



The ice cliff facing the ocean at this point has the gen- 

 eral appearance of the front of Muir Glacier, but its sub- 

 merged profile is different. Instead of deep water it 

 overlooks a shoal, from which boulders project here and 

 there and on which we saw small bergs stranded. 1 Very 

 little floating ice was visible, and no large bergs. The 

 cliff is evidently sapped at base by the wash of the waves, 

 and the process which perpetuates it is closely similar to 



the process which main- 

 tains rock cliffs along other 

 portions of the coast. 



The glacier, which farther 

 west presses against the 

 timbered ridge, flows past 

 its end to the sea, and thus 

 the extremity of the ridge 

 occupies a reentrant angle 

 in the margin of the glacier. 

 Close to the angle a stream 





m;f^^^^^ j 



^m, f^~^~r m*C^mm 





FIG. 21. SKETCH MAP OF MARGIN OF 

 LA PEROUSE GLACIER. 



The row of circles marks the position of 

 a fresh-formed moraine ridge, with overturned 

 trees. Forest is indicated by stars, sand beach 

 by dots. Approximate scale: 1 inch =2,000 feet. 



of water, escaping from the 

 glacier, has crossed the 

 ridge, eroding a deep gash, 

 in whose walls the structure 

 of the ridge is revealed. The walls are not clothed by 

 vegetation, but are somewhat cumbered by the trunks of 

 forest trees fresh-fallen from the crests on either side. The 

 stream has been very active within the last decade or two, 

 and it seems probable that all its work of erosion was 



1 If our visit was at high tide, this shoal may have been bare at low tide. 



