Report on Fukutoku-Oka-no-Ba (Japan) — September 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 9 (September 1991)
Managing Editor: Lindsay McClelland.
Fukutoku-Oka-no-Ba (Japan) Water discoloration over submarine vent
Please cite this report as:
Global Volcanism Program, 1991. Report on Fukutoku-Oka-no-Ba (Japan). In: McClelland, L. (ed.), Bulletin of the Global Volcanism Network, 16:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199109-284130.
24.285°N, 141.481°E; summit elev. -29 m
All times are local (unless otherwise noted)
A greenish water discoloration was observed during a 30 September overflight by the JMSA. No discoloration was present during a similar overflight on 21 August.
Geologic Background. Fukutoku-Oka-no-ba is a submarine volcano located 5 km NE of the pyramidal island of Minami-Ioto. Water discoloration is frequently observed from the volcano, 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.