CRKKK CUTTING A CHANNEL IN A UEEi' ACCUMULATION OF \OLCANlC ASHES AT i'.ASE 

 OF MOUNTAIN WEST OF AMALIK BAY, AUGUST 10, I9I2 



"The streams are heavilj' overloaded with the volcanic detritus, and consequently are 

 rapidly building up and extending their flood-plains, and are constructing large alluvial fans 

 at their mouths and at points of flattening grade. Avalanches and deposition at the mouths 

 of tributaries are changing the grades and even the courses of some of the streams. Lakes 

 are being rapidly fllled and great changes are being made in shore-lines." 



DEPOSITS FORMED MORE THAN 25 FEET 

 THICK 



In the area of thicker ash-fall and on 

 the stee])er mountain slopes tremendous 

 avalanches took place. The immense ac- 

 cumulations formed in this way are 

 sliown in the views from Katmai and 

 from Amahk P>ay. Much of this mate- 

 rial had, on August 12, come to rest tem- 

 porarily at least, but the enormous de- 

 posits gave evidence as to what the char- 

 acter of the avalanching must have been 

 and inspired caution in climbing steep 

 slopes. 



The dejjosits along the stream below 

 the waterfall, shown in view above, had 

 been (leei)ly trenched by the stream after 

 it spread them. A thickness of over 25 

 feet was exposed and still the base of the 

 deposits v/as not reached. This expo- 

 sure is, moreover, not at the very foot of 

 the hill, where the greatest thickness 

 must have been deposited. 



The streams are heavily overloaded 

 with the volcanic detritus, and conse- 



quently are rapidly building up and ex- 

 tending their flood-plains, and are con- 

 structing large alluvial fans at their 

 mouths and at points of flattening grade. 

 Avalanches and deposition at the mouths 

 of tributaries are changing the grades 

 and even the courses of some of the 

 streams. Lakes are being rapidly filled 

 and great changes are being made in 

 shore-lines. 



MASSES OF PUMICE COVER THE SEA 



The pumice is being washed into the 

 sea by the combined action of streams, 

 waves, and tides. There it forms great 

 floating fields, which migrate with the 

 winds and tides and greatly impede the 

 navigation of small craft such as ours. 

 An immense field of pumice which visited 

 our anchorage at Takli Island is shown 

 on page 178. The view shows the dis- 

 tance to which a dory could be forced 

 into it. This visitor came and went under 

 the influence of tidal currents and winds, 

 and constituted a menace which led us 

 to seek a more sheltered nook for our 



I7S 



