is a volcanic Japanese island in the Philippine Sea. 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. 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 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 stone tools made from obsidian in Shizuoka and Yamanashi Prefectures. Under the Ritsuryō system of the early Nara period, the island was part of Suruga Province. It was transferred to Izu Province when Izu separated from Suruga in 680 AD. During the Heian period, obsidian was the primary export from the island. See also List of islands of Japan List of volcanoes in Japan Notes References Teikoku's Complete Atlas of Japan, Teikoku-Shoin., Ltd. Tokyo 1990, External links Kozushima Village Official Website Kozushima - Japan Meteorological Agency - Japan Meteorological Agency Kozu Shima Volcano Group - Geological Survey of Japan Izu Islands Active volcanoes Islands of Tokyo Important Bird Areas of the Nanpo Islands Seabird colonies VEI-4 volcanoes