, officially named , is one of the Japanese Volcano Islands, which lie south of the Bonin Islands and together with them make up the Ogasawara Archipelago. Together with the Izu Islands, they make up Japan's Nanpō Islands. Although south of Tokyo on Honshu, Iwo Jima is administered as part of the Ogasawara Subprefecture of the Tokyo Metropolitan Government.
Only in size, the island is still volcanic and emits sulfurous gases. The highest point of Iwo Jima is Mount Suribachi at high. Although likely passed by Micronesians who made their way to the Bonins to the north, Iwo Jima was largely ignored by the Spanish, Dutch, British, and Japanese until a relatively late date after its 1543 rediscovery. The Japanese eventually colonized the island, administering it as the Ioto or Iojima Village under Tokyo's jurisdiction until all civilians were forcibly evacuated to Honshu in July 1944 near the end of World War II.
Because it was able to provide secure airfields within easy range of the Japanese Home Islands, Iwo Jima was not passed by like other Pacific fortresses; instead, the Battle of Iwo Jima between February and March 1945 was some of the fiercest fighting of the Pacific War, with Imperial Japan and the United States both suffering over 20,000 casualties. Joe Rosenthal's photograph of the second flagraising on Mount Suribachi has become one of the most famous examples of wartime photojournalism and an iconic American image. Following the Japanese surrender, the US military occupied Iwo Jima along with the other Nanpo Islands and the Ryukyus; Iwo Jima was returned to Japan with the Bonins in 1968.
Now technically part of the territory and municipal jurisdiction of Ogasawara Village, the island still has no permanent inhabitants except a Self-Defense Force base on its Central Field. Its soldiers, sailors, and airmen receive their own services from Ayase or Sayama but provide emergency assistance to communities on the Bonins who are still connected with the mainland only by an infrequent day-long ferry. As of 1991, the land of Iwo Jima was owned by six individuals, the Village of Ogasawara, and the Government of Japan. Additionally, at least eight individuals held leasehold interests in certain parts of the land owned by the village. The North Kanto Defense Bureau of the Ministry of Defense pays rent on the land lease to the individual owners and leaseholders.According to the proceeding record of the Special Committee for the Investigation of Iwo Jima, Ogasawara Village Council in 2018, private land owners and leaseholders exist.
The area of Iwo Jima continues to increase due to the uplift of the ground due to active volcanic activity; in 1911 it was , in 1945 it was , in 2014 it was and in 2023, it was .
Name
The original records of De la Torre's 1543 expedition have been lost, but he does not appear to have separately named Iwo Jima, despite later sources sometimes miscrediting him with the name Sulfur or Sulphur Island (orig. or ). Instead, he seems to have only named the Volcano Islands as a group (orig. ) after an eruptionprobably on South Iwo Jimaactive as his ship passed through the area.
Other Spanish explorers may have named or renamed the island in the years afterward.Cf., e.g., , which credits Ruy López de Villalobos with naming the island or in 1544. Certainly, John Gore was aware of Spanish accounts of the area with him when he visited in 1779 and recorded its English name as Sulphur Island.
The name was subsequently calqued into Late Middle Japanese with the Sino-Japanese form and pronunciation Iwau-tau (, , "Sulfur Island"), still romanized as Iwōtō on the control tower for the remaining airport..
The native Japanese reading of the same character is shima, which typically shifts to jima when preceded by another character. This reading was reinforced during the Second World War, when it was mistakenly used by Japanese naval officers who arrived to fortify the island ahead of US invasion, and is the source of the English name "Iwojima" (also rendered "Iwo-jima" and "Iwo Jima"), which is pronounced or ."Iwo Jima" (US) and
In modern Japanese, the /au/ has assimilated to /ō/ and the /w/ has dropped out, with the phonetic spelling Iōtō formally adopted following Japan's 1946 orthography reform. This newer form is sometimes borrowed into English as and . The high-profile Clint Eastwood films Flags of Our Fathers and Letters from Iwo Jima revived complaints from prewar residents about continued misreading of in the island's name as jima, particularly within Japanese. After formal debate, the Japanese Ministry of Land, Infrastructure, Transport, and Tourism's Geographical Survey Institute formally announced on 18 June 2007 that the official pronunciation would return to Iōtō. 硫黄島, pronounced Iōjima, is the name of a different island in Kagoshima.
Geography
Iwo Jima has an approximate area of . The most prominent feature is Mount Suribachi on the southern tip, a vent that is thought to be dormant and is high. Named after a Japanese grinding bowl, the summit of Mount Suribachi is the highest point on the island. Iwo Jima is unusually flat and featureless for a volcanic island. Suribachi is the only obvious volcanic feature, as the island is only the resurgent dome (raised centre) of a larger submerged volcanic caldera surrounding the island. The island forms part of the Kazan-retto islands Important Bird Area (IBA), designated by BirdLife International.
80 km (43 nautical miles, 50 mi) north of the island is and south is ; these three islands make up the Volcano Islands group of the Ogasawara Islands. Just south of Minami-Iō-jima are the Mariana Islands.
The visible island stands on a plateau (probably made by wave erosion) at depth about 15 m, which is the top of an underwater mountain 1.5 km to 2 km tall and 40 km diameter at base.
Eruption history Iwo Jima has a history of minor volcanic activity a few times per year (fumaroles, and their resultant discolored patches of seawater nearby). In November 2015, Iwo Jima was placed first in a list of ten dangerous volcanoes, with volcanologists saying there was a one in three chance of a large eruption from one of the ten this century.
Prehistoric Earlier: An undersea volcano started, and built up into a volcanic island. It was truncated, either by caldera-forming eruption or by sea erosion. About 760±20 BC: a large eruption with pyroclastic flows and lava destroyed a previous forested island 131±20BC and 31±20 BC: carbon-14 date of seashells found buried in lava at Motoyama (see map) Micronesian tools and carvings found in the Bonin Islands to the north suggest Iwo Jima may have been visited or inhabited as well. With limited archaeological access, however, no such remains have been found to date.
Witnessed 1543: Commanding the , the Spanish explorer Bernardo de la Torre almost certainly sighted Iwo Jima and the other Volcano Islands at some point between September 25 and October 2 while making another failed attempt to sail east across the Pacific from the Philippines to New Spain. (No attempt would be successful until 1565.) Attempting to secure reinforcements for Ruy López de Villalobos when Filipino resistance proved unexpectedly strong, De la Torre apparently passed the islands during an eruption on South Iwo Jima, realized his supply of water would be insufficient for completing his mission, and returned south to rendezvous with López de Villalobos in the Moluccas.. Over the next century, other Spanish sailors passed the islandsparticularly once Alonso de Arellano found a safe northeastern route back to Mexico from the Philippineswithout settling or formally claiming them. The Volcano Islands did, however, form part of the notional boundaries between the Spanish and Portuguese Empires in the Eastern Hemisphere following the treaties of Tordesillas and Zaragoza, such that the Spanish considered them within their sphere of influence. 15 November 1779: Following British captain James Cook's death on Hawaii, ships previously under his command landed on Iwo Jima during the return voyage from his 3rd expedition.Patrick, John M. Iwo Jima – Sulphur Island. United States Naval Institute Proceedings 76, no. 9 (September 1950): 1028-1029. Under James King and John Gore, the expedition's surveying crew mapped the island, recording a beach at sea level which was above sea level by 2015 due to volcanic uplifting. Such uplifting occurs on the island at a varying rate of between per year, with an average rate of per year.US Geophysics Research Forum, Geophysic Study Committee. Active Tectonics, p. 104. National Academies Press, 1986. Gore's visit was sometimes misunderstood or misrepresented as a new discovery, as in the report in the December 1786 supplement to The New London Magazine: Early 1945: United States armed forces landed on a beach which by 2015 was above sea level due to volcanic uplift. 28 March 1957: A phreatic eruption occurred without warning northeast of Suribachi, lasting 65 minutes and ejecting material high from one crater. Another crater, wide and deep, formed by collapse 50 minutes after the eruption ended. 9–10 March 1982: Five phreatic eruptions occurred from vents on the northwest shore of the island. 21 September 2001: A submarine eruption began from three vents southeast of Iwo-jima. It built a diameter pyroclastic cone. October 2001: A small phreatic eruption at Idogahama (a beach on the northwest coast of the island) made a crater wide and deep. May 2012: Fumaroles, and discolored patches of seawater were seen northeast of the island, indicating further submarine activity. May to June 2013: Series of smaller volcanic earthquakes. April 2018: A number of volcanic earthquakes, high white plumes up to . 30 October to 5 November 2019: Volcanic quakes and subaerial eruption. 29 April to 5 May 2020: Subaerial eruption and volcanic plume rising up to in height. 8 September to 6 October 2020: Volcanic plume up to in height and a minor eruption. 24 November 2021: Small phreatic eruption occurred with the ash plume height yet to be known.
On 11 July 2022, the first magmatic eruption in over 1000 years began just offshore. The article was cited as saying "Officials of the National Research Institute for Earth Science and Disaster Resilience (NIED) visited the site between July 12 and July 15 and observed volcanic eruptions every five minutes, which created water columns tens of meters high and spewed black smoke. The officials also observed many rocks that had washed ashore on the coast of Iwoto island. There were small cavities inside the rocks. The officials believe they are cooled lava, formed after magma has erupted, quickly cooled and solidified. The temperature on the inside of some of the rocks was as high as 120 degrees, according to the officials."
At the beginning of November 2023, a series of continuous eruptions of material resulted in a new islet breaking the surface and beginning to grow. Following continuous volcanic activity since the initial eruption the island now dubbed Niijima, Japanese for 'new island', has continued to grow and is now visible from space.
Volcanological external links 6 cross sections of stages in the c. 760±20 BC eruption SW-NE geological cross section through Suribachiyama
Climate
Iwo Jima has a tropical savanna climate (Aw) with long, hot summers and warm winters with mild nights.
History
Pre-1945 The island was first visited by a Westerner in October 1543, by Spanish sailor Bernardo de la Torre on board the carrack San Juan de Letrán when trying to return from Sarangani to New Spain.Brand, Donald D. (1967). The Pacific Basin: A History of its Geographical Explorations. New York: The American Geographical Society. p. 123.
In the late 16th century, the island was discovered by the Japanese.