Izu Ōshima (伊豆大島, Izu-ōshima?) is a volcanic island in the Izu Islands. The island is administered by the Tokyo Metropolitan government, Japan, lies about 100 km south of Tokyo, 22 km east of the Izu Peninsula and 36 km southwest of Bōsō Peninsula. Ōshima Town (大島町, Ōshima-machi?) serves as the local government of the island. The town (municipality) was formed in 1955 by the amalgamation of six separate villages (municipalities), which were:
Moto, which had been called Motomura (village) until then, became seat of the local government for the whole island as Motomachi (town).
Izu Ōshima, at 91.06 km² is the largest and closest of Tokyo's outlying islands, which also include the Ogasawara Islands. Izu Ōshima forms part of the Fuji-Hakone-Izu National Park. Izu Ōshima is a stratovolcano.
From a vantage point near the top of the cone it was possible to leap straight into the lava flow. As a result, the volcano became a popular venue for suicides. Beginning in the 1920s, several suicides occurred in the volcano every week; more than six hundred people jumped in 1936. Authorities eventually erected a fence around the base of the structure to curb the number of suicides.
Mount Mihara's major eruption in 1986 saw spectacular lava fountains up to 1.6 kilometers high. The eruption had a VEI of 3, and involved a: Central vent eruption, radial fissure eruption, explosive eruption, lava flows and a lava lake eruption. There was also a 16-km high subplinian plume. All of the island's 12,000 inhabitants were evacuated by dozens of vessels consisting of both the military and civilian volunteers.
The most recent eruption was in 1990.
In the realm of fiction, Mount Mihara was the place where the Japanese government imprisoned Godzilla in the movie The Return of Godzilla. Five years later, in the sequel Godzilla vs. Biollante, bombs placed on Mt. Mihara go off and release Godzilla from his fiery tomb. In the novel/motion picture Ring, by Suzuki Koji, it is the location where Shizuko Yamamura, mother of the infamous Sadako Yamamura, took her own life.