is a
submarine volcano that is part of the
Volcano Islands
The or are a group of three Japanese-governed islands in Micronesia. They lie south of the Ogasawara Islands and belong to the municipality of Ogasawara, Tokyo, Tokyo Metropolis, Japan. The islands are all active volcanoes lying atop ...
in the
Bonin Islands
The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic read ...
of
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
. It is located northeast of the island of
South Iwo Jima
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, image_caption = Minami-Iōtō
, image_size =
, pushpin_map = Japan complete
, pushpin_label = South Iwo Jima
, pushpin_label_position =
, pushpin_map_alt =
, pushpin_relief ...
.
Geography
The volcano is part of a larger elongated
submarine volcano with two peaks and with a magma composition of
trachyandesite
Trachyandesite is an extrusive igneous rock with a composition between trachyte and andesite. It has little or no free quartz, but is dominated by sodic plagioclase and alkali feldspar. It is formed from the cooling of lava enriched in alka ...
. The volcano itself has erupted on multiple occasions with the last eruption before 2021 occurring during 2010. The first island to form when this volcano was discovered formed in 1904–5 and with a few more forming during the course of the 1900s.
History
The earliest recorded eruption of Fukutoku-Okanoba in 1904 formed an
ephemeral
Ephemerality (from the Greek word , meaning 'lasting only one day') is the concept of things being transitory, existing only briefly. Academically, the term ephemeral constitutionally describes a diverse assortment of things and experiences, fr ...
island named Shin-Iwo-jima (''New Sulfur Island''). Other ephemeral islands have also formed, the most recent of which formed in 1986.
In 2010, the Japanese coast guard spotted steam rising above the ocean and water discoloration of the surrounding area.
In 2021, the
Japan Meteorological Agency
The , abbreviated JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. It is charged with gathering and providing results for the public in Japan that are obtained from data based on daily scientific observation an ...
(JMA) reported that a
submarine eruption
Submarine eruptions are those volcano eruptions which take place beneath the surface of water. These occur at constructive margins, subduction zones and within tectonic plates due to hotspots. This eruption style is far more prevalent than subae ...
occurred at Fukutoku-Okanoba volcano at 6:20 a.m. local time on August 13. On August 16, it was confirmed that a new island had formed as a result of the latest eruption.
In October 2021, large quantities of pumice pebbles from Fukutoku-Okanoba damaged fisheries, tourism, the environment, 11 ports in Okinawa and 19 ports in
Kagoshima prefecture.
Clean-up operations took 2-3 weeks.
Timeline
* 1904 - 1905 : height , is substantially circular island around about is formed by submarine eruption. In June 1905, it shrank to a height of less than and eventually became a reef .
* 1914 : An island with a height of and a circumference of is formed by a submarine eruption in January. At the end of the year, collapses will begin in various places.
* 1916 : The island is submerged.
* 1986 : An island was formed by a submarine eruption in January, but the island submerged in a short period of time until the end of March.
* 2005 : The submarine eruption on July 2 creates a huge water vapor column with a height of and a diameter of .
* 2007 : On December 1, the Japan Meteorological Agency began announcing eruption warnings . Since then, "warning of surrounding sea areas" has been continued.
* 2008 : Discolored water was confirmed for several months from around February.
* 2010 : Due to the submarine eruption on February 3, eruptions and discolored water are observed in the surrounding area.
* 2013 : On September 27, observations by the Maritime Self-Defense Force confirmed a green discoloration of the sea surface and the eruption of white bubbles on the sea surface within a radius of .
* 2020 : On February 4, yellow-green discolored water was confirmed by the Japan Coast Guard observation.
* 2021 : On August 13, the eruption of the seafloor was observed. The height is about . Volcanic lightning was also observed. Volcanic ash is Bashi Channel beyond the South China Sea has been reached in the northeastern part.
This eruption is considered to be one of the largest in Japan after the war.
Observations by the Japan Coast Guard on August 15 confirmed Niijima, which is about in diameter.
On August 17, Niijima was divided into two parts, east and west, and on October 20, it was confirmed that Niijima on the east side had disappeared.
In October, a large amount of pumice seen to have erupted in this eruption, or more distant Daito , Okinawa , Amami drifted to coast around.
Gallery
File:The eruption of Fukutoku-Oka-no-Ba 03.jpg, Eruption situation of Fukutoku Okanoba (Jan 20, 1986)
File:The eruption of Fukutoku-Oka-no-Ba 04.jpg, Fukutoku Okanoba and South Iwo Jima during eruption activity (Jan 20, 1986)
File:The eruption of Fukutoku-Oka-no-Ba 05.jpg, Pumice stones lifted by the eruption fill the surface of the sea. The distant island is South Iwo Jima (Jan 20, 1986)
file:Fukutoku-Okanoba Eruption 08-12-2022 2127Z to 08-13-2022 0335Z.gif, Himawari-8 satellite images of the August 12 to August 13, 2021 eruption of Fukutoku-Okanoba
See also
*
List of volcanoes in Japan
This is a list of active and extinct volcanoes in Japan. An Orange background indicates a volcano considered active by the Japan Meteorological Agency.
Hokkaido
Honshū
Izu Islands
Ogasawara Archipelago
The Ogasawara Archipelag ...
References
{{reflist, 2
, refs=
[{{cite web
, url=https://www.data.jma.go.jp/svd/vois/data/tokyo/331_Fukutoku-Oka-no-Ba/331_history.html
, title=福徳岡ノ場 有史以降の火山活動
, publisher=気象庁
, accessdate=2021-08-16
, archive-date=2021-08-13
, archive-url=https://web.archive.org/web/20210813063354/https://www.data.jma.go.jp/svd/vois/data/tokyo/331_Fukutoku-Oka-no-Ba/331_history.html
, url-status=live
]
[{{cite web
, publisher=気象庁地震火山部 火山監視情報センター
, url=https://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/monthly_v-act_doc/tokyo/2008y/331_08y.pdf
, title=平成20年(2008年)の福徳岡ノ場の火山活動
, accessdate=2021-08-16
, archive-date=2021-08-13
, archive-url=https://web.archive.org/web/20210813020224/https://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/monthly_v-act_doc/tokyo/2008y/331_08y.pdf
, url-status=live
]
External links
Article on 2005 eruption
Volcano Islands
Izu–Bonin–Mariana Arc
Submarine volcanoes
Active volcanoes
Ephemeral islands
Volcanoes of Tokyo
Former islands from the last glacial maximum