Iōjima (Kagoshima)

Iōjima (硫黄島), also known as Satsuma Iōjima (薩摩硫黄島) or Tokara Iōjima (吐噶喇硫黄島), is one of the Satsunan Islands, usually classed with the Ōsumi Islands, belonging to Kagoshima Prefecture, Japan. Along with Takeshima and Kuroshima, it makes up the three-island village of Mishima, Kagoshima Prefecture, Japan. The island, 11.65 km² in area, has a population of 142 persons.

Native name:
硫黄島, Iō-jima
Iojima Kagoshima Japan
Aerial view of the island. (February 2008)
LocationEast China Sea
Coordinates30°47′27″N 130°17′46″E / 30.79083°N 130.29611°ECoordinates: 30°47′27″N 130°17′46″E / 30.79083°N 130.29611°E
ArchipelagoŌsumi Islands
Area11.65 km2 (4.50 sq mi)
Length5.5 km (3.42 mi)
Width4.0 km (2.49 mi)
Coastline14.5 km (9.01 mi)
Highest elevation703.7 m (2,308.7 ft)
Highest pointIōdake
PrefecturesKagoshima Prefecture
DistrictKagoshima District
Population121 (December 1, 2006)
Pop. density10.38 /km2 (26.88 /sq mi)


Iōjima is one of the Ōsumi islands, and is located 110 kilometres (59 nmi) south of Kagoshima. The island has an area of approximately 11.65 square kilometres (4.50 sq mi) with a length of 5.5 kilometres (3.4 mi) in length from east to west and 4.0 kilometres (2.5 mi) from north to south.

2015 Satsuma-Iojima Iodake
Mount Iōdake. May, 2015. Taken from the east.

Iōjima is of volcanic origin, and is the northern edge of the Kikai Caldera, a stratovolcano rising from the ocean floor to 703.7 metres (2,309 ft) above sea level at its highest peak (Mount Iōdake). Kikai Caldera is ranked class A for volcanic activity. It is constantly erupting, emitting massive amounts of sulfur dioxide which causes damage to agricultural products. Hot springs high in iron concentration from the port bottom gush and due to contact with oxygen, the port waters change to a reddish-brown color. Due to the sulfur, the sea area around the island is yellow in color. This gave rise to the name "Sulfur Island" (Iōjima).

The climate of Iōjima is classified as subtropical, with a rainy season from May through September.

Shōwa Iōjima, a small uninhabited island, is located just offshore to the north.


Historically Iōjima is one of the islands identified as Kikai Island, an island of exile mentioned in the Heike Monogatari, where the conspirator Shunkan was exiled. However, there are other islands in the Ryukyu Islands which also make the same claim.

During the Edo period, Iōjima was part of Satsuma Domain and was administered as part of Kawabe District. In 1896, the island was transferred to the administrative control of Ōshima District, Kagoshima, and from 1911 was part of the village of Toshima, Kagoshima. From 1946-1952, the southern seven islands in the Toshima group belonging to the Tokara archipelago came under the administration of the United States as part of the Provisional Government of Northern Ryukyu Islands; however, since Iōjima is located north of 30 degrees North, it remained Japanese territory during this time, and came under the administration of the village of Mishima in Kagoshima Prefecture.


The island can be reached by bi-weekly ferry service to the city of Kagoshima on the mainland. Travel time is about 3 hours. Satsuma Iojima Airport was opened in 1973 in conjunction with a resort development by the Yamaha Corporation. Ownership of the airport was transferred to Mishima Village after the resort closed in 1994, but there is no scheduled service.


From the Meiji period, mining of sulfur and silica were important to the local economy. However, the mine closed in 1964 due to increased volcanic activity and a large drop in prices due to cheaper imports. The population of the island, which reached 604 people in 1960, dropped to 186 by 1970 due to the mine closure. In October 1973, the Yamaha Corporation established a resort complex on the island, but the venture went bankrupt in April 1983. Peacocks brought in as decoration for the hotel have become feral, and can be found throughout the island. The present economic basis of the island is now mainly fishing, agriculture (beef cattle, bamboo shoots, camellia oil products) and seasonal tourism.

External links

  • Satsuma-Iojima - Japan Meteorological Agency (in Japanese)
  • "Satsuma-Iojima: National catalogue of the active volcanoes in Japan" (PDF). - Japan Meteorological Agency
  • Satsuma-iojima - Geological Survey of Japan
  • Kikai - Geological Survey of Japan
  • Kikai: Global Volcanism Program - Smithsonian Institution

Iōjima may refer to:

An island known as Iwo Jima in English. In Japanese, it is officially known as Iōtō, although at one point it was officially also Iōjima

Iōjima, Tokyo, a former village in Tokyo on the same island

Iōjima, Kagoshima, one of the three islands that forms the village of Mishima, Kagoshima, Japan; one of the Ōsumi Islands

Iōjima, Nagasaki, a former town in Nagasaki Prefecture, Japan

List of mines in Japan

This list of mines in Japan is subsidiary to the list of mines article and lists working, defunct and future mines in the country. For practical purposes stone, marble and other quarries may be included in this list. This list is inherently incomplete and shows only a selection of the most notable mines.


Iron (triangle mark)




other metals

Coal, oil or oil slate


other non-metal

stone, crystals and complex compounds

Mount Iō (Iōjima)

Mount Iō (硫黄岳, Iō-dake) also Mount Iwo is an active rhyolitic lava dome on Iōjima in Kagoshima Prefecture, Japan. It sits within the borders of the town of Mishima.

The mountain is made up of non-alkali felsic rock and pyroclasitic flows.


Shunkan (俊寛) (c. 1143 – 1179) was a Japanese monk who, after taking part in the Shishigatani plot to overthrow Taira no Kiyomori, was exiled along with two others to Kikai-ga-shima. His story is featured in the Heike monogatari, and in a number of traditional derivative works, including the Noh play Shunkan and jōruri play Heike Nyogo-ga-shima. Twentieth century authors Kan Kikuchi and Ryūnosuke Akutagawa also produced works entitled Shunkan.

Shōwa Iōjima

Shōwa Iōjima (昭和硫黄島), also known as Shōwa Shintō (昭和新島), is one of the Satsunan Islands, usually classed with the Ōsumi Islands, belonging to Kagoshima Prefecture, Japan. A deserted volcanic island, it is located just off the northern shore of Iōjima, Kagoshima.

Surtseyan eruption

A Surtseyan eruption is a type of volcanic eruption that takes place in shallow seas or lakes. It is named after the island of Surtsey off the southern coast of Iceland.These eruptions are commonly phreatomagmatic eruptions, representing violent explosions caused by rising basaltic or andesitic magma coming into contact with abundant, shallow groundwater or surface water. Tuff rings, pyroclastic cones of primarily ash, are built by explosive disruption of rapidly cooled magma.

Ōsumi Islands


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