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Report on Fukutoku-Oka-no-Ba (Japan) — March 1984


Scientific Event Alert Network Bulletin, vol. 9, no. 3 (March 1984)
Managing Editor: Lindsay McClelland.

Fukutoku-Oka-no-Ba (Japan) Discolored water observed on 12 days in 1983

Please cite this report as:

Global Volcanism Program, 1984. Report on Fukutoku-Oka-no-Ba (Japan) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 9:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198403-284130



24.285°N, 141.481°E; summit elev. -29 m

All times are local (unless otherwise noted)

Frequent monitoring of several known submarine volcanoes has continued. . . . [Discolored water was observed at Fukutoku-Okanoba in 1983 on 14 January, 2 and 15 February, 3 and 15-16 March, 24 May, 16 June, 20 July, 25 October, 11 November, and 12 December; and was not visible 12 July, 25 August, and 13 September.]

Geological Summary. Fukutoku-Oka-no-ba is a submarine volcano located 5 km NE of the island of Minami-Ioto. Water discoloration is frequently observed, and several ephemeral islands have formed in the 20th century. The first of these formed Shin-Ioto ("New Sulfur Island") in 1904, and the most recent island was formed in 1986. The volcano is part of an elongated edifice with two major topographic highs trending NNW-SSE, and is a trachyandesitic volcano geochemically similar to Ioto.

Information Contacts: JMA, Tokyo.