The Izu Islands (伊豆諸島, Izu Shotō; Japanese pronunciation: [i.(d)zɯ, i.(d)zɯ ɕoꜜ.toː]) are a group of volcanic islands stretching south and east from the Izu Peninsula of Honshū, Japan. Administratively, they form two towns and six villages; all part of Tokyo Prefecture. The largest is Izu Ōshima, usually called simply Ōshima.
Although usually called the "Seven Islands of Izu" (伊豆七島 in Japanese), there are in fact more than a dozen islands and islets. Nine among them are currently inhabited.
The Islands of Tokyo (東京諸島, Tokyo-shotō), also known as the Insular Area of Tokyo Metropolis (東京都島嶼部, Tōkyō-to-tōshobu) or Izu-Ogasawara islands (伊豆・小笠原諸島, Izu-Ogasawara-shotō), consist of the Izu and Ogasawara (also known as Bonin) island chains to the south of the Izu Peninsula.
The Tokyo Metropolitan Assembly (東京都議会, Tōkyō-to gikai) is the prefectural parliament of Tokyo Metropolis.
Its 127 members are elected every four years in 42 districts by single non-transferable vote. 23 electoral districts equal the special wards, another 18 districts are made up by the cities, towns and villages in the Western part of the prefecture, one district consists of the outlying islands (Ogasawara and Izu Islands).
The Izu–Bonin–Mariana (IBM) arc system is a tectonic plate convergent boundary in Micronesia. The IBM arc system extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, the Bonin Islands, and the Mariana Islands; much more of the IBM arc system is submerged below sealevel. The IBM arc system lies along the eastern margin of the Philippine Sea plate in the Western Pacific Ocean. It is the site of the deepest gash in Earth's solid surface, the Challenger Deep in the Mariana Trench.
The IBM arc system formed as a result of subduction of the western Pacific plate. The IBM arc system now subducts mid-Jurassic to Early Cretaceous lithosphere, with younger lithosphere in the north and older lithosphere in the south, including the oldest (~170 million years old, or Ma) oceanic crust. Subduction rates vary from ~2 cm (1 inch) per year in the south to 6 cm (~2.5 inches) in the north.
Japonic or Japanese–Ryukyuan (Japanese: 日琉語族, romanized: Nichiryū gozoku) is a language family comprising Japanese, spoken in the main islands of Japan, and the Ryukyuan languages, spoken in the Ryukyu Islands. The family is universally accepted by linguists, and significant progress has been made in reconstructing the proto-language, Proto-Japonic. The reconstruction implies a split between all dialects of Japanese and all Ryukyuan varieties, probably before the 7th century. The Hachijō language, spoken on the Izu Islands, is also included, but its position within the family is unclear.
Most scholars believe that Japonic was brought to the Japanese archipelago from the Korean peninsula with the Yayoi culture during the 1st millennium BC. There is some fragmentary evidence suggesting that Japonic languages may still have been spoken in central and southern parts of the Korean peninsula (see Peninsular Japonic) in the early centuries AD.
The small group of Hachijō dialects (八丈方言, Hachijō hōgen), natively called Shima Kotoba (島言葉; [ɕima kotoba], "island speech"), are, depending on classification, either the most divergent form of Japanese, or comprise a branch of Japonic languages (alongside mainland Japanese, Northern Ryukyuan, and Southern Ryukyuan). Hachijō is currently spoken on two of the Izu Islands south of Tokyo (Hachijō-jima and the smaller Aogashima) as well as on the Daitō Islands of Okinawa Prefecture, which were settled from Hachijō-jima in the Meiji period. It was also previously spoken on the island of Hachijō-kojima, which is now abandoned. Based on the criterion of mutual intelligibility, Hachijō may be considered a distinct Japonic language, rather than a dialect of Japanese.
Hachijō is a descendant of Eastern Old Japanese, retaining several unique grammatical and phonetic features recorded in the Azuma-dialect poems of the 8th-century Man'yōshū and the Fudoki of Hitachi Province. Hachijō also has lexical similarities with the dialects of Kyushu and even the Ryukyuan languages; it is not clear if these indicate that the southern Izu islands were settled from that region, if they are loans brought by sailors traveling among the southern islands, or if they might be independent retentions from Old Japanese.
Izu Ōshima (伊豆大島, Izu-ōshima) is an inhabited volcanic island in the Izu archipelago and borders Sagami Bay and the Pacific Ocean, off the coast of Honshu, Japan, 22 km (14 mi) east of the Izu Peninsula and 36 km (22 mi) southwest of Bōsō Peninsula. As with the other islands in the Izu Island group, Izu Ōshima forms part of the Fuji-Hakone-Izu National Park. Izu Ōshima, at 91.06 km (35.16 sq mi) is the largest and closest of Tokyo's outlying islands, which also include the Ogasawara Islands.
The Seven Islands of Izu (伊豆七島, Izu Shichitō; Japanese pronunciation: [i.(d)zɯ, i.(d)zɯ ɕi̥.tɕiꜜ.toː]) are the seven inhabited islands of the Izu Islands that belong to the Tokyo Islands of Tokyo Prefecture, Japan.
The name comes from the fact that there were the seven main inhabited islands in the Izu Islands during the Edo period: Izu Oshima, To-shima, Niijima, Kozushima, Miyakejima, Mikurajima, and Hachijojima.
Chichijima (父島) is the largest and most populous of the Bonin Islands. Chichijima is about 240 km (150 mi) north of Iwo Jima. 23.5 km (9.1 sq mi) in size, the island is home to about 2,120 people (2021). Connected to the mainland only by a day-long ferry that runs a few times a month, the island is nonetheless organized administratively as the seat of Ogasawara Village in the coterminous Ogasawara Subprefecture of the Tokyo Metropolitan Government. Together with the Volcano and Izu Islands, it makes up Japan's Nanpō Islands.
Some Micronesian tools and carvings have been found elsewhere in the Bonins, but Chichijima was long uninhabited when it was rediscovered. Ignored by the Spanish, Dutch, and Japanese Empires for centuries, it was finally claimed by a passing British captain in 1828 and settled by an international group from the Hawaiian Kingdom two years later, the original nucleus of the Bonin Islanders. Britain subsequently yielded to Japanese claims and colonization of the island, which established two villages at Ōmura (大村) and Ōgimura-Fukurosawa (扇村袋沢村). These were formally incorporated in 1940, just before the civilian population was forcibly evacuated to Honshu in 1944 during the end of World War II.
Iwo Jima (硫黄島, Iōtō, Iōjima; English: /ˌiː.woʊ.ˈdʒiː.mə/, Japanese: [i.oː.toː] or [i.oː.(d)ʑi.ma], lit. 'Sulfur Island') 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 1,200 km (750 mi) south of Tokyo on Honshu, Iwo Jima is administered as part of the Ogasawara Subprefecture of the Tokyo Metropolitan Government.
Only 29.86 square kilometers (11.53 sq mi) in size, the island is still volcanic and emits sulfurous gases. The highest point of Iwo Jima is Mount Suribachi at 169 m (554 ft) 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.