Report on Fukutoku-Oka-no-Ba (Japan) — March 1986
Scientific Event Alert Network Bulletin, vol. 11, no. 3 (March 1986)
Managing Editor: Lindsay McClelland.
Fukutoku-Oka-no-Ba (Japan) January island eroded below sea level
Please cite this report as:
Global Volcanism Program, 1986. Report on Fukutoku-Oka-no-Ba (Japan) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 11:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198603-284130.
24.285°N, 141.481°E; summit elev. -29 m
All times are local (unless otherwise noted)
Water discoloration was seen on every overflight in February and March. Wave action gradually eroded the island built by the January eruption, and JMSA personnel reported that it was entirely below sea level by the time of their overflight on 26 March.
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; JMSA.