Report on Fukutoku-Oka-no-Ba (Japan) — January 1977
Natural Science Event Bulletin, vol. 2, no. 1 (January 1977)
Managing Editor: David Squires.
Fukutoku-Oka-no-Ba (Japan) Possible submarine eruption in December 1974
Please cite this report as:
Global Volcanism Program, 1977. Report on Fukutoku-Oka-no-Ba (Japan). In: Squires, D. (ed.), Natural Science Event Bulletin, 2:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197701-284130.
24.285°N, 141.481°E; summit elev. -29 m
All times are local (unless otherwise noted)
[A table of possible submarine eruptions based on aerial observations of water discoloration by the Japanese Maritime Safety Agency included an entry for 24.28°N, 141.50°E, in December 1974. This location is very close to Fukutoku-Okanoba. In March 1975 another observation was listed at 24.42°N, 141.32°E; this is ~25 km NW of Fukutoku-Okanoba and ~36 km S of Iwo-jima.]
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: AFP; U.S. Defense Mapping Agency.