June, 1920] 



The Great Mageik Landslide 



349 



Slide, which dammed Katmai Canyon, causing when it broke 

 the Great Flood, has been estimated by Maynard from his 

 survey to contain, 88,000,000 cubic yards, which though far 

 inferior to the Mageik SUde, is nearly twice as large as any of 

 the other records quoted above. The Noisy Mountain SUde 

 looks much bigger than the one in Katmai Canyon, but the 

 survey has not yet been carried into that area, so that it is 

 impossible to give any estimate of its dimensions. 



Photograph by Robert F. Griggs 

 ONE OF THE CONICAL PILES OF THE SURFACE OF THE SLIDE. 



The rock on top shows clearly enough that the mound was not built up around a 



crater. In the distance is a leaning pillar of columnar lava suggestive 



of the conditions of the cliff which fell to form the Slide. In the 



foreground is much white ash from the eruption, which 



does not appear on the mound, probably because 



of readjustment of the surface after the 



close of the ashfall. 



As each of the slides cited above was considered a very 

 remarkable event, it is evident that those of the Katmai District 

 are to be ranked as among the most notable examples of their 

 class on record. They are, however, by no means the greatest 

 of such phenomena that have been reported. Aside from 

 records of slow-moving landslips of the ordinary type with 

 which we have no concern, there are accounts of other catas- 

 trophes belonging to the same violent type of landslide as ours, 

 which so far exceed the slides we have described as to quite 

 dwarf them by comparison. 



