Report on Fukutoku-Oka-no-Ba (Japan) — January 1997
Bulletin of the Global Volcanism Network, vol. 22, no. 1 (January 1997)
Managing Editor: Richard Wunderman.
Fukutoku-Oka-no-Ba (Japan) Submarine venting continues to discolor seawater
Please cite this report as:
Global Volcanism Program, 1997. Report on Fukutoku-Oka-no-Ba (Japan). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 22:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199701-284130.
24.285°N, 141.481°E; summit elev. -29 m
All times are local (unless otherwise noted)
On 12 December, a Japan Maritime Safety Agency aviator reported yellow-green discoloration of seawater at Fukutoku-Okanoba over a 50 x 200 m area. On 27 January, pale green discoloration was seen by an aviator of the Japan Maritime Safety Agency covering an area of 2,000 x 100 m.
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: Volcanological Division, Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan.