THE GREAT ERUi'TIOX OF SAKURA-JDIA IN 1914. 21 



coveiy from the keen stratigraphie observations made by 

 I. Friedlaender, although he seems to be unconscious of the real 

 extension of the lapilli plateau land. Through the effort of the 

 German naturalist,^^ some light is thrown on this vulcanologically 

 little known group of Iwô-jima and Kuchino-Erabu. 



He speaks of Iwo-jdia (Fig. 1, /; Fig. 2) as a high flat of 

 100-200 m., being built up of vitroandesite overlaid by tufaceous 



1) ' Ueber einige japanisclie VuUv.ine.' Mitleil. Deutsch. Ges. f. iSfahir- u. Völkerkunde Ostaslens. 

 Bd. Xn. Teil 2, Tokyo, 1910. 



For the sake of comparison and the cognate relation which they bear with Halmra-jima, a 

 few notes will be appended chiefly from the work cited above, on the islands now under con- 

 sideration (see Fig. 2). 



a) The active Iwo-jima (' Sulphur Island ') lies 18 miles from Cape Kaimon, and has a 

 circumference of 12 km., the western half is a high flat, 200 m. in height, being built up of 

 vitrodacite, tuff-sandstone and pumice, capped with lava-sheet. The eastern half is occupied 

 by an active cone, 770 jn. high, which rests upon the pumice terrace. The cone carries a top- 

 crater having a diameter of 7-800 m. and a depth of 50. Fumaroles and solfataras are hissin» 

 from the bottom. The island is the well-known producer of sul^jhur and supjjorts 900 in- 

 habitants of whom one-third find their employment in working the sulj^hur deposits. We loiow 

 of no historic record of any eruption. As it was colonized seven hundi-ed years a^o, old 

 families must keep some records of activity, which may be found if search is made. At the 

 beginning of April, 1914, it showed an unusual mood of vulcanism in throwing up smoke in 

 sympathy with Sakura-jima (See p. 5). 



h) The smaller Takeno-shima lies to the east of it. It is a flat island bounded on all 

 sides by cliffs. The geological structure is exactly the same as the foundation of the preceding. 

 Friedlaender imagines the island to be a part of a ruined cone whose center lies in the bottom 

 of the southern coast. To the writer it seems more plausible to take the island for a patch of 

 shattered lapilli land. We entirely miss i^etrographic details. Younger cones are not found on 

 the island. 



o) The westerly-lying 1vubo-shim.i is a 'black' wooded conical island of the size of the 

 preceding. It is said (' Geographic Scraps of Satsuma, Osumi, and Hyûga ') that to reach the 

 steep top (250 m.) is by no means easy, and there are cataracts within the thick forest on the 

 way up to the crater which seems to be of recent origin. We know nothing about its rocks and 

 eruptions. 



d) Kuchixo-Ee.abu lies not far from Yaku (see p. 5). It is ill-defined, stretching VI km. 

 from N.N.W. to S.S.E. According to Friedlaender, it is likewise an elevated flat (150 ju.) and 

 cliff-bound, and has the same lithologie elements and structure as IwG-jima and others. It 

 .•arries upon the foundation the overlapping cones (G65m.), the north cone being older and 

 craterless, the southern one still preserving a fresh solfataric crater. At the middle stands the 

 Latest-bom giant with an apical crater, 500 m. in diameter and 50 m. in depth, where strong 

 fumaroles are hissing and depositing sulphur. A hot spring gushes at the northeast coast. A 

 violent eruption is said to have occurred in 1839, when many people were buried alive. At the 

 end of [March, 1914, it Avas rumored that it had thrown up thick s)noke, which was observed 

 from the easterly-lying Yakn-shima, in .sympathy with Sakura-jima. 



