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Report on Fukutoku-Oka-no-Ba (Japan) — November 1992


Bulletin of the Global Volcanism Network, vol. 17, no. 11 (November 1992)
Managing Editor: Lindsay McClelland.

Fukutoku-Oka-no-Ba (Japan) Smaller zone of discolored water; no new pumice

Please cite this report as:

Global Volcanism Program, 1992. Report on Fukutoku-Oka-no-Ba (Japan) (McClelland, L., ed.). Bulletin of the Global Volcanism Network, 17:11. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199211-284130



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

All times are local (unless otherwise noted)

Overflights by the JMSA on 12 and 18 November revealed a smaller and weaker area of discolored water over the submarine volcano than on 10 November. The height and size of the dark plume seen by fishermen on 10 November are not known, nor is is known whether the plume contained tephra. Floating pumice was observed that day, but none has been reported since then.

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; JMSA.