Ōnoharajima
Encyclopedia
is a group of volcanic
deserted islands located in the Philippine Sea
approximately 180 kilometres (111.8 mi) south of Tokyo
and 10 kilometres (6.2 mi) west of Miyakejima
, in the northern portion of the Izu archipelago
, Japan
. The group is also known as from its profile.
. The island is the remnant of an andesite
lava dome
with sheer sides, the only visible portion of a submarine volcanic caldera. The above sea-level portion has a surface area of approximately 0.2 square kilometers, with a summit height of 114 metres (374 ft) on the main islet of .
Located in the Kuroshio Current
, the area has abundant sea life, and is popular with sports fishermen and scuba divers.
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
deserted islands located in the Philippine Sea
Philippine Sea
The Philippine Sea is a marginal sea east and north of the Philippines occupying an estimated surface area of 2 million mi² on the western part of the North Pacific Ocean...
approximately 180 kilometres (111.8 mi) south of Tokyo
Tokyo
, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...
and 10 kilometres (6.2 mi) west of Miyakejima
Miyakejima
is an island in the Izu group, southeast of Honshū, Japan, administered by the Tokyo Metropolitan government, with an area of 55.50 km². The island, 180 km south of Tokyo, is located at 34.5N and 139.34E. As of January 1, 2006, the population of the island is 2884...
, in the northern portion of the Izu archipelago
Izu Islands
The 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. The largest is Izu Ōshima, usually called simply Ōshima....
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The group is also known as from its profile.
Geography
Ōnoharajima consists of nine main islets and several smaller rocks and stacksStack (geology)
A stack is a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, isolated by erosion. Stacks are formed through processes of coastal geomorphology, which are entirely natural. Time, wind and water are the only factors involved in the...
. The island is the remnant of an andesite
Andesite
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...
lava dome
Lava dome
|250px|thumb|right|Image of the [[rhyolitic]] lava dome of [[Chaitén Volcano]] during its 2008–2009 eruption.In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano...
with sheer sides, the only visible portion of a submarine volcanic caldera. The above sea-level portion has a surface area of approximately 0.2 square kilometers, with a summit height of 114 metres (374 ft) on the main islet of .
Located in the Kuroshio Current
Kuroshio Current
The Kuroshio is a north-flowing ocean current on the west side of the North Pacific Ocean. It is similar to the Gulf Stream in the North Atlantic and is part of the North Pacific ocean gyre...
, the area has abundant sea life, and is popular with sports fishermen and scuba divers.