Iwo Jima

Lore & Background

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. Other Spanish explorers may have named or renamed the island in the years afterward. 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, still romanized as Iwōtō on the control tower for the remaining airport. The native Japanese reading of the same character 硫 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'). 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. 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.

Reader's Guide

Iwo Jima has an approximate area of 21 km². The most prominent feature is Mount Suribachi on the southern tip, a vent that is thought to be dormant and is 169 m 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 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 north of the island is North Iwo Jima and 50 km south is South Iwo Jima; 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 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. The area of Iwo Jima continues to increase due to the uplift of the ground due to active volcanic activity; in 1911 it was 19.3 km², in 1945 it was 20.3 km², in 2014 it was 23.16 km² and in 2023, it was 24 km².

Did You Know?

• 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.
• As of 1991, the land of Iwo Jima was owned by six individuals, the Village of Ogasawara, and the Government of Japan.
• Iwo Jima has a history of minor volcanic activity a few times per year (fumaroles, and their resultant discolored patches of seawater nearby).