268 



N. Powers— Volcanic Domex in the Pacific. 



nvcr in is IS. The crust, Avas elevated by a liquid lava beneath 

 until ii assumed the form, of a dome 200 to 300 feet high 

 ant] 2000 feet in diameter. By August the dome had increased 

 in heighl until it- was higher than tlio lower portions of the 

 walls of the Kilaiiean sink. The sluggish basalt was seen 



Kit;. 5. 



Fig. 5. Sambondake, an island in the Fujiyama-Bonin Island volcanic 

 chain 80 miles south of Oshima, which may be a volcanic spine. 



through cracks in the dome and occasionally it flowed out 



through these cracks and down the sides, increasing the size 



of the dome. 12 



The lava beneath the dome disappeared in the fall of 1848 



and did not rise again until April, 1849, when, for a short 



time, very fluid basalt was thrown from openings in the top 



of the dome to heights of from 50 to GO feet. With the next 



rise of the lava in 1852 the opening in the top of the dome 



had enlarged to a diameter of 200 feet. The sides of the dome 



were partly flooded by the rise of 1855 and they soon after 



fell into the lake. 



12 W. T. Brigham, The volcanoes of Kilauea and Mauna Loa, Mem. B. P. 

 Bishop Museum, Honolulu, vol. ii, no. 4, p. 61ff., 1909. 



