Ushishir
Encyclopedia
Ushishir is an uninhabited volcanic island located in the centre of the Kuril Islands
chain in the Sea of Okhotsk
in the northwest Pacific Ocean
. Its name is derived from the Ainu language
for "hot spring
".
These islets are the tops of a partially submerged volcano. The southern island (Yankicha ) consists of the summit caldera and has a maximum width of 2.5 kilometers. The caldera has a diameter of 1.6 kilometers, and is breached on the south, forming a sea-water crater bay
. The bay has an estimated depth of 30 meters, and there is strong evidence of ongoing underwater volcanic activity
, as evidenced by frequent bubbles, altered water chemistry and the presence of bacteria mats. Two small lava dome
s for small islands in the central lagoon, and numerous fumarole
s and hot springs are along the southeast caldera shoreline. The island’s highest point is 401 meters high, and is on the eastern shore.
The northern islet (Ryponkicha ) is the larger of the two, and consists of a portion of the volcano’s flank, with sheer cliffs rising 131 meters from the sea.
Ushishir is still active volcano with a major eruption with the last known eruption in 1884.
tribes from Rasshua
, who regarded the island as a sacred land, which they identified as the home of the thunder god. Remains of Ainu huts have been found on the northern slopes of Yankicha’s crater bay. Claimed by the Empire of Russia, sovereignty
over Ushishir was passed to the Empire of Japan
per the Treaty of Saint Petersburg (1875) along with the rest of the Kurile Islands. Approaches to the island are difficult due to frequent fogs, rapid ocean current
s and the presence of numerous small offshore rocks. The island was formerly administered as part of Shimushiro District of Nemuro Subprefecture
of Hokkaidō
. After World War II
, the island came under the control of the Soviet Union
, and is now administered as part of the Sakhalin Oblast
of the Russian Federation.
Kuril Islands
The Kuril Islands , in Russia's Sakhalin Oblast region, form a volcanic archipelago that stretches approximately northeast from Hokkaidō, Japan, to Kamchatka, Russia, separating the Sea of Okhotsk from the North Pacific Ocean. There are 56 islands and many more minor rocks. It consists of Greater...
chain in the Sea of Okhotsk
Sea of Okhotsk
The Sea of Okhotsk is a marginal sea of the western Pacific Ocean, lying between the Kamchatka Peninsula on the east, the Kuril Islands on the southeast, the island of Hokkaidō to the far south, the island of Sakhalin along the west, and a long stretch of eastern Siberian coast along the west and...
in the northwest Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. Its name is derived from the Ainu language
Ainu language
Ainu is one of the Ainu languages, spoken by members of the Ainu ethnic group on the northern Japanese island of Hokkaidō....
for "hot spring
Hot spring
A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...
".
Geology
Ushishir consists of two islets connected by a narrow spit of land with an area of 5 km²These islets are the tops of a partially submerged volcano. The southern island (Yankicha ) consists of the summit caldera and has a maximum width of 2.5 kilometers. The caldera has a diameter of 1.6 kilometers, and is breached on the south, forming a sea-water crater bay
Crater Bay
Crater Bay is a bay located in the Ushishir Islands, which are part of the Kuril Islands, in the Russian Far East. This bay was formed by volcano which is now extinct....
. The bay has an estimated depth of 30 meters, and there is strong evidence of ongoing underwater volcanic activity
Submarine volcano
Submarine volcanoes are underwater fissures in the Earth's surface from which magma can erupt. They are estimated to account for 75% of annual magma output. The vast majority are located near areas of tectonic plate movement, known as ocean ridges...
, as evidenced by frequent bubbles, altered water chemistry and the presence of bacteria mats. Two small 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...
s for small islands in the central lagoon, and numerous fumarole
Fumarole
A fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...
s and hot springs are along the southeast caldera shoreline. The island’s highest point is 401 meters high, and is on the eastern shore.
The northern islet (Ryponkicha ) is the larger of the two, and consists of a portion of the volcano’s flank, with sheer cliffs rising 131 meters from the sea.
Ushishir is still active volcano with a major eruption with the last known eruption in 1884.
History
Ushishir had no permanent habitation prior to European contact, but was visited in summer by the AinuAinu people
The , also called Aynu, Aino , and in historical texts Ezo , are indigenous people or groups in Japan and Russia. Historically they spoke the Ainu language and related varieties and lived in Hokkaidō, the Kuril Islands, and much of Sakhalin...
tribes from Rasshua
Rasshua
Rasshua , is an uninhabited volcanic island near the center of the Kuril Islands chain in the Sea of Okhotsk in the northwest Pacific Ocean, from Ushishir and southwest of Matua. Its name is derived from the Ainu language for “fur coat”.-Geology:...
, who regarded the island as a sacred land, which they identified as the home of the thunder god. Remains of Ainu huts have been found on the northern slopes of Yankicha’s crater bay. Claimed by the Empire of Russia, sovereignty
Sovereignty
Sovereignty is the quality of having supreme, independent authority over a geographic area, such as a territory. It can be found in a power to rule and make law that rests on a political fact for which no purely legal explanation can be provided...
over Ushishir was passed to the Empire of Japan
Empire of Japan
The Empire of Japan is the name of the state of Japan that existed from the Meiji Restoration on 3 January 1868 to the enactment of the post-World War II Constitution of...
per the Treaty of Saint Petersburg (1875) along with the rest of the Kurile Islands. Approaches to the island are difficult due to frequent fogs, rapid ocean current
Ocean current
An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...
s and the presence of numerous small offshore rocks. The island was formerly administered as part of Shimushiro District of Nemuro Subprefecture
Nemuro Subprefecture
is a subprefecture of Hokkaidō, Japan. The Japanese claim the disputed Southern Kurile Islands as part of this subprefecture....
of Hokkaidō
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...
. After World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, the island came under the control of the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
, and is now administered as part of the Sakhalin Oblast
Sakhalin Oblast
Sakhalin Oblast is a federal subject of Russia comprising the island of Sakhalin and the Kuril Islands.The oblast has an area of 87,100 km² and a population of 546,695...
of the Russian Federation.
External links
Further reading
- Gorshkov, G. S. Volcanism and the Upper Mantle Investigations in the Kurile Island Arc. Monographs in geoscience. New York: Plenum Press, 1970. ISBN 0-306-30407-4
- Krasheninnikov, Stepan Petrovich, and James Greive. The History of Kamtschatka and the Kurilski Islands, with the Countries Adjacent. Chicago: Quadrangle Books, 1963.
- Rees, David. The Soviet Seizure of the Kuriles. New York: Praeger, 1985. ISBN 0-03-002552-4
- Takahashi, Hideki, and Masahiro Ōhara. Biodiversity and Biogeography of the Kuril Islands and Sakhalin. Bulletin of the Hokkaido University Museum, no. 2-. Sapporo, Japan: Hokkaido University Museum, 2004.