Jan., 1919] Effects of the Eruption on Vegetation 183' 



particles of ejecta carried by the blasts, which gave them the 

 effect of terrific sand blasts. This he inferred from the manner 

 in which the bark and trunks of trees were shredded where 

 exposed, and from the fact that even very thin fabrics sufficed 

 to protect the flesh of victims which otherwise suffered severely. 



There is, however, little evidence that a sand blast accom- 

 panied the eruption of Katmai. Near the volcano and in 

 Soluka Creek, at a distance of about ten miles, the limbs of the 

 trees and bushes were damaged by the hail of falling ejecta 

 which must have been of considerable violence in areas where 

 so much ash and pumice fell. But no evidence of shredding by 

 sand blasts, such as Worcester figures, was seen. 



The only place on the mainland where investigations were 

 made to ascertain the manner of death of the vegetation within 

 the first year after the eruption was at Russian Anchorage. 

 (Griggs 2 ). Here the buds of the alders had all been killed, but 

 the bark was not only intact but alive and in condition to have 

 made a complete and rapid recovery if there had been living 

 buds to furnish an outlet for the vitality of the plants. (See 

 page 184.) The present appearance of the trees in Katmai 

 Valley indicates that the eruption probably left them in the 

 same condition. (See page 185.) It is difficult to see how such 

 damage could be accomplished by a sand blast. It would 

 seem much more likely to have resulted from hot winds. 



As would be expected, the zone of complete destruction by 

 the blast is surrounded by an area of minor injury. This is the 

 third of our series of zones which we passed over above without 

 discussion. It has been observed, especially in the area between 

 the mouth of Katmai River and Kashvik Bay. Because of the 

 position of the mountain wall of Katmai Valley, the area of 

 devastation does not intergrade with this district of slight 

 injury but is sharply separated from it. 



Since this district lies out of the area covered by wind blown 

 ash, the ashfall here is almost devoid of dust and fine particles, 

 being composed of fragments of pumice heavy enough to be 

 relatively little affected by air currents. The total amount of 

 ash (about one inch) was so slight as to do practically no damage 

 in itself. And, at first sight, we were inclined to conclude that 

 the vegetation in this area was in no way injured by the erup- 

 tion, but closer examination indicates that the bare places ort 



