£>. Powers — Volcanic Domes in the Pacific. 



265 



augite andesite were thrown out, indicating that the newly 

 injected magma had arisen to within a short distance of the 

 surface. Some of the craterlets were active for only a few 

 hours, so that the trees on their sides were partly buried but 



Fig. 3. 



Fig. 3. The dome O-Usu as seen from the west. The south side of the 

 dome has been uplifted and the west side steepened by an explosion (after 

 Kato). 



Fig. 4. 



Fig. 4. The dome Ko-Usu looking northwest. The east side is supposed 

 to have slightly subsided (after Kato). 



not overturned, while others were intermittently explosive for 

 several days, forming symmetrical cones and craters with 

 diameters as great as 600 feet. In August, 1915, steam was 

 still issuing from a few of the larger craters. 



The elevation of the strip of land between the new craters 

 and Lake Toya did not become noticeable until August 6, 



