Scientific Results of the Katmai Expeditions of the 

 National Geographic Society. 



II. ARE THE TEN THOUSAND SMOKES REAL 



VOLCANOES?* 



Robert F. Griggs. 



In the original account of the discovery and exploration of 

 the Valley of Ten Thousand Smokes in the National Geographic 

 Magazine, February, 1918, I felt free to describe the phenomena 

 in the light of our conclusions regarding them, although I could 

 not, at that time, digress to give the data upon which our 

 conclusions were based. This paper is written with the purpose 

 of supplying the data that could not be elaborated in the 

 former account, in order that the student of volcanic phenomena 

 may judge for himself the validity of the conclusions reached. 



It should be emphasized at the outset that, while there are 

 certain conclusions concerning the nature of the Valley of 

 Ten Thousand Smokes which may be considered to be well 

 supported by indubitable evidence, there are also many larger 

 problems looming in the background which as yet can hardly 

 be stated with clearness, much less solved. 



The primary question which must arise in the mind of any- 

 one who considers the Valley is as to the nature of its activity. 

 Are its smokes real volcanoes? Or are they of a more superficial 

 character caused merely by the vaporization of surface water? 

 It is evident enough that such a Valley full of "Smokes" 

 might be due, either (1) to the percolation of surface waters 

 down through the fragmental ejecta of the recent eruption 

 to a flow of lava beneath, which, though erupted before the fall 

 of ash, still retains a high temperature' and vaporizes the water 

 that comes in contact with it; or (2) the smokes might derive 

 their gases from molten magma beneath the surface, in which 

 case the vents would be as truly volcanoes as is Vesuvius 

 itself. 



Certain of the features of the Valley seem to favor each of 

 these hypotheses It will be well, therefore, to pass these 

 facts in review. But before doing so, it will be desirable to 



*Copyright, 1919, by National Geographic Society, Washington, D. C. All 

 rights reserved. 



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