287 
(lit. 2 p. 167), and the water of this crater lake must have acted 
a similar part as that of the Klut. 
Thus the first sediment of the Katmai explosion would not have 
been as GriaGs supposes the ash deposited as subaërial sediment but 
the hot lahar, which reduced the trees to charcoal. Afterwards there 
must have supervened a phase in which all the water of the crater was 
blown out and the ash was thrown up dry and fell down on an 
extensive area, and finally (as a phenomenon that is not connected 
directly with the eruption) the rain caused a cold mud flow on the 
South slope of Mt. Katmai. 
Let us now trace the quantities of solid material and water. 
Grices estimates the quantity of solid material of the great mud 
flow of the Valley of ten thousand smokes at 4096 million cubic 
metres (lit. 5, p. 137) *) and the cubical capacity of the crater-hole 
after the eruption at 4500 million cubic yards = 3442 million cu.m. 
By the eruption the rim was lowered from 7500 feet (2280 m.) to 
a maximum of 6970 feet (2120 m.) (lit. 4, p. 167) or a minimum 
of 5200 feet (1580 m.) (lit. 3, p. 59). According to Griggs the 
crater-hole had before the eruption of 1912 a cubical capacity of 
11,000 million cubic yards = 8415 million eu.m. 
The content of the crater lake will therefore have amounted to 
8415 million cu.m. before the eruption, so that the above mentioned 
proportion for the Katmai volcano would amount to: 
A 4096 
W 3415 = 0,49. 
If the cubic capacity of the crater lake before the eruption had 
been smaller and the quantity of solid material in the lahar greater, 
there would still have been enough water in the Katmai crater to 
cause the hot mud flow which was observed by Griaas in the 
Valley of ten thousand smokes. 
The question whether the distribution of the mud-flow can be 
brought into harmony with the supposition that the Katmai crater 
was the source of the hot mud flow has still to be answered. 
Griggs gives on page 132 of his paper of Dec. 1918 (lit. 5), (fig. 2) 
a map with the distribution of the great hot mud flow. On the 
West side of Mt. Katmai the hot mud flow attains the contour line of 
3000 feet (910 m.), while the lahar running in a northwest direction 
1) In lit.6, p. 241 Griacs computes the total quantity of the sand- (read : mud- 
flow) „as greater than a cubic mile”. 
19* 
