Smith Island (Japan)
Encyclopedia
is a volcanic
, deserted island located in the Philippine Sea
approximately 110 kilometres (68.4 mi) off the coast of Aogashima
, near the southern end of the Izu archipelago
, Japan
.
and olivine
pillar
with sheer sides, the only visible portion of an active submarine volcanic caldera extending south of the island with a circumference of approximately 10 kilometres (6.2 mi). The above sea-level portion has a height of 134 metres (439.6 ft). The island is estimated to have been created by a volcanic eruption around 20,000 years ago. In the immediate vicinity are numerous exposed and awash rocks. Due to its shape and heavy seas it is difficult to disembark on the island, although at times fishermen are known to have landed. The abundance of fish in the surrounding waters have made it attractive for both sport and commercial fishing.
Sumisu-tō is administratively part of Tokyo Metropolis.
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 island 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 110 kilometres (68.4 mi) off the coast of Aogashima
Aogashima
is a village located in Hachijō Subprefecture, Tokyo, Japan.-Geography:Aogashima Village covers the island of Aogashima, the southernmost and most isolated populated island in the Izu archipelago in the Philippine Sea, south of central Tokyo, and south of Hachijōjima, its nearest populated...
, near the southern end 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...
.
Geography
The island a basaltBasalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
and olivine
Olivine
The mineral olivine is a magnesium iron silicate with the formula 2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface....
pillar
Stack (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...
with sheer sides, the only visible portion of an active submarine volcanic caldera extending south of the island with a circumference of approximately 10 kilometres (6.2 mi). The above sea-level portion has a height of 134 metres (439.6 ft). The island is estimated to have been created by a volcanic eruption around 20,000 years ago. In the immediate vicinity are numerous exposed and awash rocks. Due to its shape and heavy seas it is difficult to disembark on the island, although at times fishermen are known to have landed. The abundance of fish in the surrounding waters have made it attractive for both sport and commercial fishing.
History
The island has been known by Japanese fishermen and mariners from an early time. In 1870, a submarine eruption was recorded NNE of the island, resulting in the formation of a new islet, named , with a height of 13 metres (42.7 ft). The islet has subsequently sunk beneath sea level due to erosion. From 1974-1977, a series of underwater eruptions have been recorded, discoloring water in the area. In November 1991, a fishing vessel reported that a large section of the island’s northern face had collapsed, resulting in a significant change in its profile. Further changes to the island’s profile were recorded after 1992 earthquakes.Sumisu-tō is administratively part of Tokyo Metropolis.