Fukutoku-Okanoba Volcano | John Seach


Volcano Islands, Japan

24.28 N, 141.485 E
summit elevation -14 m
Submarine Volcano

Fukutoku-Okanoba Volcano is located 5km NE of the small island Minami-iwo-jima.

In 2021 twenty-four ships washed ashore on the western side of Iwo-Jima Island, which were sunk in the second world war battle for Iwo-Jima. The ships were mobilised by underwater eruptions of Fukutoku-Okanoba volcano.

2010 Eruption
An underwater eruption occurred 5 km north-northwest of Iwo Jima Island on 3rd February. The eruption was observed by Japanese coast guard. Ash and steam was visible rising 100 m above the ocean surface. Yellow-green colour was visible on the ocean surface in December 2009.

2005 Eruption
A submarine eruption occurred at Fukutoku-Okanoba on 2nd July 2005. Orange-brown discoloration of the water extended for 1 km.

1992 Eruption
Pumice was erupted by a submarine eruption.

1986 Eruption
An undersea eruption formed a new island on 18th January 1986. The island disappeared under the sea by 8th March.

1953 Eruption
Sulphur odour and discolored water was visible at the volcano on 1st December.

1950 Eruption
On 1st February 1950 emission of sulphur 40-50m in diameter and 2 miles in length occurred.

1914 Eruption
Submarine eruption at Fukutoku-Okanoba was witnessed on 23rd January 1914. Height of white smoke for about 3000 m. Constant eruption on 24th of January. On 25th January formation of volcanic islands. Circumference of about 8km, a height of about 300m. On 12th February there was a decrease in the number of eruptions. Niijima island had a major axis of about 1.3 km, short axis 900 m, and a height of about 117 m. On 14th February the island was 1.8 km long and 180 m high. The island disappeared by 9th April 1916.

1904-05 Eruption
Explosions heard in mid June. Steam and ash eruption. Formation of volcanic islands. Diameter about 4.5km, a height of about 150m. Eruption finished in late January 1905. On 15-16 May 1905 sounds like a cannon were heard. By 16th June 1905 the size of the island was reduced. Height about 3m, a small island about 450m in length. The island has disappeared under the water by 1st June 1906.

Further Reading
Ito, K., Kato, S., Takahashi, M. and Saito, A., 2011. Volcanic topography of Fukutoku- Oka-no-ba volcano in Izu-Ogasawara arc after the 2010 eruption.

SUN, C.H., STERN, R.J., YOSHIDA, T. and KIMURA, J.I., 1998. Fukutoku-oka-no-ba Volcano: A new perspective on the Alkalic Volcano Province in the Izu–Bonin–Mariana arc. Island Arc, 7(3), pp.432-442.

Fukutoku-Okanoba Volcano Eruptions

2010, 2005-07, 1995?, 1993?, 1992, 1991?, 1987?, 1986, 1976?, 1974, 1973,
1950-1972 (uncertain eruptions), 1914, 1904-05