Report on Fukutoku-Oka-no-Ba (Japan) — April 1977
Natural Science Event Bulletin, vol. 2, no. 4 (April 1977)
Managing Editor: David Squires.
Fukutoku-Oka-no-Ba (Japan) Water discoloration observed during August 1976
Please cite this report as:
Global Volcanism Program, 1977. Report on Fukutoku-Oka-no-Ba (Japan). In: Squires, D. (ed.), Natural Science Event Bulletin, 2:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197704-284130.
24.285°N, 141.481°E; summit elev. -29 m
All times are local (unless otherwise noted)
[A report of surface discoloration in March was removed at JMA's request.] The last reported activity in this area was a [green] discoloration in August 1976.
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, Tokyo.