Report on Fukutoku-Oka-no-Ba (Japan) — 29 December-4 January 2022
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 29 December-4 January 2022
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2021. Report on Fukutoku-Oka-no-Ba (Japan) (Sennert, S, ed.). Weekly Volcanic Activity Report, 29 December-4 January 2022. Smithsonian Institution and US Geological Survey.
Fukutoku-Oka-no-Ba
Japan
24.285°N, 141.481°E; summit elev. -29 m
All times are local (unless otherwise noted)
The Japan Coast Guard reported that during a 27 December overflight of Fukutoku-Oka-no-Ba, observers noted that the island formed in mid-August had become smaller since 14 December, and had almost eroded below the ocean surface. No eruptive activity was observed, though brownish water spouted from the E end of the island. Yellowish-green water and a string of floating pumice, 400 m long, was circulating 5 km E. Discolored water was visible around almost the entire coast of Minami-Ioto (5 km SSW).
Geological Summary. Fukutoku-Oka-no-ba is a submarine volcano located 5 km NE of the island of Minami-Ioto. Water discoloration is frequently observed, 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.
Source: Japan Coast Guard