Nov., 1918] Recovery of Vegetation at Kodiak 41 



The bottom (gray) layer was made up of fairly large particles, 

 giving the deposit the character of fine sand; the second (terra 

 cotta) layer was very much finer, almost all dust ; while the top 

 layer (gray) was similar to the first but very much finer. The 

 top layer has almost everywhere blown away, leaving the present 

 surface of the ash composed usually of the middle brown layer. 

 Because of the fineness and angularity of the particles, the 

 physical properties of this layer are very peculiar. When dry, 

 it is all blown away in a cloud of dust by the gentlest breeze. 

 But when moist, the particles settle close together, interlocking 

 one with another, till they form a hard compact terrain which 

 coheres almost as though the particles were cemented together. 

 If more water is added there comes a point at which the inter- 

 locking particles are floated free from each other, and the mass 

 suddenly changed from a rigid solid to a perfect liquid. This 

 layer, therefore, in the wet climate of Kodiak, is little affected 

 by wind action, but is rapidly eroded by the streams, and it is 

 this fine material especially which has accumulated in the ponds 

 and tundras, sometimes to the depth of several feet. In such 

 deep beds, the facility with which its condition changes from 

 solid to liquid becomes a matter of considerable moment. 

 This change may often be brought about suddenly by stirring 

 the mixture, without the addition of more water. It will be 

 seen that there are here conditions favorable to the formation 

 of dangerous quicksands. In the examination of such places, 

 one often finds on retracing his steps that the place, over which 

 he came on hard ground but a moment before, has become a 

 soupy liquid under the disturbance caused by his tread. Several 

 men have been seriously mired in such places. 



POND PLANTS LARGELY SURVIVED. 



Where the ash deposit in the filled ponds is wet enough to 

 remain in a semi-fluid condition, the original aquatic vegetation 

 has to a large extent recovered, and is thriving as before the 

 eruption. A little pond in the forest north of Kodiak (see page 

 40) will furnish a good illustration of the situation. So much 

 ash has been washed into the pond that it is completely filled 

 up, so that the surface remains dry and hard during dry periods. 

 In the center, formerly covered with open water, are water 

 lillies (Nymphaea polysepald) thriving apparently as well as 

 ever, for they flower and fruit abundantly. Surrounding the 

 former open water is a zone of buckbean (Menyanthes trifoliata} 



