176 The Ohio Journal of Science [Vol. XIX, No. 3, 



leaves of the native perennial vegetation, in some cases causing 

 defoliation. But to the cultivated annuals of the gardens it 

 was so injurious as to cause their complete destruction. 



The magnitude of this feature of the eruption can be better 

 envisaged if one imagine the volcano located in New York City, 

 in which case crops would be destroyed as far away as Pitts- 

 burgh, Portland, (Maine), and Richmond, (Virginia). It 

 would not be fair to suppose, however, that in such a hypo- 

 thetical eruption all crops would be destroyed within the area 

 indicated, for the occurrence of such acid rains is sporadic, 

 being dependent both on the drift of the fumes under the wind 

 and on the occurrence of the atmospheric conditions necessary 

 to produce precipitation at the time when the acid laden clouds 

 were passing over the given area. 



The effects of the eruption on vegetation in the vicinity of 

 Kodiak, which is typical of the second zone where the ashfall* 

 was so heavy as to smother all of the smaller plants, have 

 been discussed in earlier papers and require no amplification 

 here.^'^~^ 



Conditions in the third zone, comprising the outlying 

 fringes beyond the areas of greater destruction on the mainland, 

 may be best described after consideration of the inner zones. 



TREES KILLED IN AREAS OF LITTLE ASHFALL. 



The fourth zone, where trees and bushes were killed, although 

 the ashfall was so light as not to destroy the herbage, occupies 

 an area of about 666 square miles lying to the south, west, and 

 north of the volcano, beginning with the west side of Katmai 

 Valley and extending around the Valley of Ten Thousand 

 Smokes into the unexplored country to the northeast of the 

 volcano. The position of this zone is determined by the fact 

 that the west wind which blew during the eruption carried the 

 ash cloud off in the direction of Kodiak, so that much of the 

 area relatively close to the volcano was only lightly covered 

 with ash. (See map, page 174.) 



' Rigg, Geo. B. The Efifects of the Katmai Eruption on Marine Vegetation. 

 vScience II. 40: 509-513. 1914. 



- Griggs, Robert F. The Effect of the Eruption of Katmai on Land Vegetation. 

 BulL Am. Geogr. Soc. 47: 193-203. Figs. 1-10. 1915. 



3 , . Scientific Results of the Katmai Expeditions. I. The 



Recovery of Vegetation at Kodiak. Ohio Journal of Science. 19: 1-57. Figs. 

 1-34. 1918. Includes a digest of literature pertinent to the present paper. 



