Raikoke (, ), also spelled Raykoke, is, as of 2019, a Russian uninhabited

volcanic island Geologically, a volcanic island is an island of volcanic origin. The term high island can be used to distinguish such islands from low islands, which are formed from sedimentation or the uplifting of coral reefs (which have often formed ...

near the centre of the

Kuril Islands The Kuril Islands or Kurile Islands are a volcanic archipelago administered as part of Sakhalin Oblast in the Russian Far East. The islands stretch approximately northeast from Hokkaido in Japan to Kamchatka Peninsula in Russia, separating the ...

chain in the

Sea of Okhotsk The Sea of Okhotsk; Historically also known as , or as ; ) is a marginal sea of the western Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands on the southeast, Japan's island of Hokkaido on the sou ...

in the northwest

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

, distant from the island of Matua. Its name is derived from the

Ainu language Ainu (, ), or more precisely Hokkaido Ainu (), is a language spoken by a few elderly members of the Ainu people on the northern Japanese island of Hokkaido. It is a member of the Ainu language family, itself considered a language family isola ...

, from the Hokkaido Ainu word "hellmouth".

Geology

Raikoke is roughly circular, with a length of with a width of , and an area of . The island is a

stratovolcano A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...

, its lava composed primarily of basalt. The cone rises above a submarine terrace with a depth of to a maximum height of above sea level. The steep-walled crater is wide and deep with

lava flow Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

s extending along the eastern half of the island. The volcano has most recently erupted in 1765, 1778, 1924 and 2019. The 1778 and 1924 Raikoke eruptions were classified on the

Volcanic Explosivity Index The volcanic explosivity index (VEI) is a scale used to measure the size of explosive volcanic eruptions. It was devised by Christopher G. Newhall of the United States Geological Survey and Stephen Self in 1982. Volume of products, eruption c ...

scale (that ranges from zero to eight) as VEI-4 or greater. For comparison the volcano Anak Krakatoa eruption in 2018 was also rated as a VEI-4 event. The 1778 eruption of Raikoke was the largest of the recent volcanic events destroying the upper third of the island. The only known fatalities from the eruptions was during the 1778 eruption when fifteen were killed from falling lava bombs.

2019 eruption

At approximately 4:03 am, 22 June 2019 it erupted, with a plume of ash and gas reaching between and , passing the

tropopause The tropopause is the atmospheric boundary that demarcates the lowest two layers of the atmosphere of Earth – the troposphere and stratosphere – which occurs approximately above the equatorial regions, and approximately above the polar regi ...

and allowing

stratospheric The stratosphere () is the second-lowest layer of the atmosphere of Earth, located above the troposphere and below the mesosphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher (c ...

injection of

ash Ash is the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash is the ...

and

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is r ...

. A study with the

ESA The European Space Agency (ESA) is a 23-member international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 in the context of European ...

satellite Sentinel-5P revealed volcano's sulphur dioxide plume had clustered into distinct structures in the 72 hours following the eruption. One of these plumes was a swirling stratospheric mass of sulphur dioxide that circled the globe three times and ascended to an altitude of some through the radiative heating of ash. Sentinel-5P and

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

CALIPSO CALIPSO was a joint NASA (US) and CNES (France) environmental satellite, built in the Cannes Mandelieu Space Center, which was launched atop a Delta II rocket on April 28, 2006. Its name stands for Cloud-Aerosol Lidar and Infrared Pathfinder Sa ...

mission showed signs of

anticyclonic A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...

motion for this plume. The ESA satellite

Aeolus In Greek mythology, Aiolos, transcribed as Aeolus (; ; ) refers to three characters. These three are often difficult to tell apart, and even the ancient mythographers appear to have been perplexed about which Aeolus was which. Diodorus Siculus m ...

confirmed that the structure was anticyclonic. Such self-containing and long-lived anticyclonic structures have long been associated with large

wildfire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

s, but stable volcanic plumes are seldom reported and only form in certain conditions.

Fauna

Raikoke is one of five major

Steller sea lion The Steller sea lion (''Eumetopias jubatus''), also known as Steller's sea lion or the northern sea lion, is a large, near-threatened species of sea lion, predominantly found in the coastal marine habitats of the northeast Pacific Ocean and th ...

rookeries on the Kuril Islands and in the spring and summer it is home to one of the largest

northern fulmar The northern fulmar (''Fulmarus glacialis''), fulmar, or Arctic fulmar is an abundant seabird found primarily in subarctic regions of the North Atlantic and North Pacific oceans. There has been one confirmed sighting in the Southern Hemisphere, ...

aggregations on the Kurils; crested and

parakeet auklet The parakeet auklet (''Aethia psittacula'') is a small seabird of the North Pacific. Parakeet Auklets used to be placed on its own in the genus ''Cyclorrhynchus'' ( Kaup, 1829) but recent morphological and genetic evidence suggest it should be pl ...

pigeon guillemot The pigeon guillemot (''Cepphus columba'') () is a species of bird in the auk family, Alcidae. One of three species in the genus ''Cepphus'', it is most closely related to the spectacled guillemot. There are five subspecies of the pigeon guille ...

, and black-legged kittiwake also nest on the island.Kondratyev, A. Y., Litvinenko, N. M., Shibaev, Y. V., Vyatkin, P. S., & Kondratyeva, L. F. (2000)
The breeding seabirds of the Russian Far East
''Seabirds of the Russian Far East'', 37–81. Captain Henry James Snow reported that in 1883 some 15,000

northern fur seal The northern fur seal (''Callorhinus ursinus'') is an eared seal found along the north Pacific Ocean, the Bering Sea, and the Sea of Okhotsk. It is the largest member of the fur seal subfamily (Arctocephalinae) and the only living species in the ...

s inhabited the island. However, by the 1890s only "a few scores" were recorded captured there, almost certainly due to

overexploitation Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to ...

by fur hunters. Currently no fur seals reproduce on Raikoke. Raikoke

History

Raikoke was visited by hunting and fishing parties of the Ainu, but there was no permanent habitation at the time of European contact. The island appears on an official map showing the territories of

Matsumae Domain file:Matsumae Nagahiro.jpg, 270px, Matsumae Nagahiro, final daimyo of Matsumae Domain The Matsumae Domain (松前藩), a prominent domain during the Edo period, was situated in Matsumae, Matsumae Island (Ishijima), which is currently known as M ...

, a

feudal domain A demesne ( ) or domain was all the land retained and managed by a lord of the manor under the feudal system for his own use, occupation, or support. This distinguished it from land sub-enfeoffed by him to others as sub-tenants. In contrast, th ...

Edo Japan The , also known as the , is the period between 1600 or 1603 and 1868 in the history of Japan, when the country was under the rule of the Tokugawa shogunate and some 300 regional ''daimyo'', or feudal lords. Emerging from the chaos of the Sengok ...

dated 1644, and these holdings were officially confirmed by the

Tokugawa shogunate The Tokugawa shogunate, also known as the was the military government of Japan during the Edo period from 1603 to 1868. The Tokugawa shogunate was established by Tokugawa Ieyasu after victory at the Battle of Sekigahara, ending the civil wars ...

in 1715. It was subsequently claimed by the

Russian Empire The Russian Empire was an empire that spanned most of northern Eurasia from its establishment in November 1721 until the proclamation of the Russian Republic in September 1917. At its height in the late 19th century, it covered about , roughl ...

;

sovereignty Sovereignty can generally be defined as supreme authority. Sovereignty entails hierarchy within a state as well as external autonomy for states. In any state, sovereignty is assigned to the person, body or institution that has the ultimate au ...

initially passed to Russia under the terms of the

Treaty of Shimoda The Treaty of Shimoda (下田条約, ''Shimoda Jouyaku'') (formally Treaty of Commerce and Navigation between Japan and Russia 日露和親条約, ''Nichi-Ro Washin Jouyaku'') of February 7, 1855, was the first treaty between the Russian Empire, a ...

, but was returned to the

Empire of Japan The Empire of Japan, also known as the Japanese Empire or Imperial Japan, was the Japanese nation state that existed from the Meiji Restoration on January 3, 1868, until the Constitution of Japan took effect on May 3, 1947. From Japan–Kor ...

per the Treaty of Saint Petersburg along with the rest of the Kuril islands. The island was formerly administered as part of Shimushu District of

Nemuro Subprefecture is a Subprefectures of Hokkaido, subprefecture of Hokkaido, Hokkaido Prefecture, Japan. Japan claims the southern parts of the Kuril Islands dispute, disputed Kuril Islands (known as the Northern Territories in Japan) as part of this subprefectur ...

Hokkaidō is the second-largest island of Japan and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by railway via the Seikan Tunnel. The ...

. After

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, it came under the control of the

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

, and is now administered as part of the

Sakhalin Oblast Sakhalin Oblast ( rus, Сахали́нская о́бласть, r=Sakhalinskaya oblastʹ, p=səxɐˈlʲinskəjə ˈobləsʲtʲ) is a federal subject of Russia (an oblast) comprising the island of Sakhalin and the Kuril Islands in the Russian ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

Notes

References

Global Volcanism Program

External links

* {{Authority control Active volcanoes Islands of the Sea of Okhotsk Islands of the Russian Far East Stratovolcanoes of Russia Islands of the Kuril Islands Uninhabited islands of Russia Volcanoes of the Kuril Islands Mountains of the Kuril Islands Holocene stratovolcanoes