is a

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plat ...

Japanese island in the Philippine Sea. Nussbaum, Louis-Frédéric. (2005)
"''Izu Shotō'',"
''Japan Encyclopedia,'' p. 412. The island is administered by Tōkyō and is located approximately northwest of the Miyake-jima and southwest of the Nii-jima. It is one of the Izu Seven Islands group of the seven northern islands of the Izu archipelago. Kōzushima is administratively part of Kōzushima Village under Ōshima Subprefecture of Tokyo Metropolis. , the island's population was 1,952. Kōzushima is also within the boundaries of the Fuji-Hakone-Izu National Park.

Geology

Kōzu-shima is a compound volcanic island 6 km in length with a maximum width of 4 km. The island is formed from a cluster of eighteen lava domes, with rhyolite and pyroclastic ash deposits. The highest of these lava domes, , has a height of , and was last active in 838 AD per the ancient Japanese history

Shoku Nihon Kōki is an officially commissioned Japanese history text. Completed in 869, it is the fourth volume in the Six National Histories. It covers the years 833–850. Background Following the earlier national history ''Nihon Kōki'' (840), in 855 Emperor ...

. Compared with most of the other islands in the Izu archipelago, Kōzu-shima is relatively flat, with small eroded hills, and lacks the high coastal cliffs found on the other islands. Earthquake swarms have occurred at Kōzu-shima during the 20th century.

Climate

Important Bird Area

The island has been recognised as an Important Bird Area (IBA) by

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

because it supports populations of Japanese wood pigeons, Tristram's storm petrels, Japanese murrelets, Ijima's leaf-warblers, Pleske's grasshopper warblers and Izu thrushes.

History

Kōzu-shima has been inhabited since at least the Japanese Paleolithic era, and archaeologists have found

Jōmon period The is the time in Japanese history, traditionally dated between 6,000–300 BCE, during which Japan was inhabited by a diverse hunter-gatherer and early agriculturalist population united through a common Jōmon culture, which reached a c ...

stone tools made from obsidian in Shizuoka and

Yamanashi Prefecture is a prefecture of Japan located in the Chūbu region of Honshu. Yamanashi Prefecture has a population of 817,192 (1 January 2019) and has a geographic area of 4,465 km2 (1,724 sq mi). Yamanashi Prefecture borders Saitama Prefecture to the ...

s. Under the

Ritsuryō , , is the historical law system based on the philosophies of Confucianism and Chinese Legalism in Japan. The political system in accord to Ritsuryō is called "Ritsuryō-sei" (律令制). ''Kyaku'' (格) are amendments of Ritsuryō, ''Shiki' ...

system of the early

Nara period The of the history of Japan covers the years from CE 710 to 794. Empress Genmei established the capital of Heijō-kyō (present-day Nara). Except for a five-year period (740–745), when the capital was briefly moved again, it remained the c ...

, the island was part of

Suruga Province was an old province in the area that is today the central part of Shizuoka Prefecture. Suruga bordered on Izu, Kai, Sagami, Shinano, and Tōtōmi provinces; and was bordered by the Pacific Ocean through Suruga Bay to the south. Its abbrev ...

. It was transferred to Izu Province when Izu separated from Suruga in 680 AD. During the

Heian period The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kanmu, moved the capital of Japan to Heian-kyō (modern Kyoto). means "peace" in Japan ...

, obsidian was the primary export from the island.

Notes

References

* ''Teikoku's Complete Atlas of Japan'', Teikoku-Shoin., Ltd. Tokyo 1990,

External links

Kozushima Village Official Website

- Japan Meteorological Agency * - Japan Meteorological Agency

- Geological Survey of Japan * {{DEFAULTSORT:Kozushima Izu Islands Active volcanoes Islands of Tokyo Important Bird Areas of the Nanpo Islands Seabird colonies VEI-4 volcanoes