THE GREAT ERUPTION OF SAKURA-JIMA IN 1914. 53 



(ceramicite) thrown out from the Nabé-yama vonts during tho 

 Ih'st phase of tho recent volcanic activity. 



orioix of Grlijin of the new islands.— The foregonig pyrogemc 



New 



Islands islaiids iiiado thcii" appoaraiicc as the outcome of at- 

 tendant submarine effusion of lava during and after the eruption 

 in 1779. The following views as to their origin may be men- 

 tioned : a) They are sometimes spoken of simply as vents on 

 the rupture line that traversed the body of Sakura-jima, as the 

 Nabé-yama vents in the last eruption, b) It may also be suggest- 

 ed, although no one seems as yet to have given utterance to this 

 view, that they are the loci of ventholes on tho front of the gas- 

 pent and cooling submarine lava that plunged into the sea down 

 the mountain slope in a fiery stream from the twin vent, the east 

 and west Idgona or ' fire -holes ' near the northern top (Fig. 11). 

 Neither view is applicable here as a working hypothesis, if the 

 bathymétrie condition of the surrounding sea be critically examined. 



The new-born islands occur in diffuse manner and rise preci- 

 pitously from the bottom GO fathoms deep. Local depressions of 

 the same depth intervene between the shore and the islands, so 

 that there is no rooni for doubt that there exists no real connec- 

 tion of lava- flows between the insular masses and Sakura-jima 

 (Text-fig. 11). 



It seems to the writer that they represent the positions of 

 ventholes of what Wolff '^ styles the central eruption upon a local 

 magma reservoir of satellitic injection fed through a narrow chan- 

 nel from the main macula under Sakura-jima, just as, according to 

 Daly,^^ Kilauea is fed by Manna Loa in the Hawaiian islands. The 



1) F. V. "SVolff, ' Der Vulkanismus. ' Bd. I. 



2) 'The îs.iture of Volciinic. Action.' I'roc. Am. Antd. Arts and Sciences, Vol. 47, 19D 



