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58-731: The Lesser Antilles Volcanic Arc is a volcanic arc that forms the eastern boundary of the Caribbean Plate . It is part of a subduction zone , also known as the Lesser Antilles subduction zone , where the oceanic crust of the North American Plate is being subducted under the Caribbean Plate. This subduction process formed a number of volcanic islands, from the Virgin Islands in the north to

116-451: A tectonic plate composed of relatively thin, dense oceanic lithosphere sinks into the Earth's mantle beneath a less dense overriding plate. The overriding plate may be either another oceanic plate or a continental plate. The subducting plate, or slab , sinks into the mantle at an angle, so that there is a wedge of mantle between the slab and the overriding plate. The boundary between

174-737: A feudal lord of Japan, became independent from the Ando clan (the family of Goro Ando). The Japanese administration first took nominal control of the islands during the Edo period (1603-1868) in the form of claims by the Matsumae clan . The Shōhō Era Map of Japan ( Shōhō kuni ezu ( 正保国絵図 ) ), a map of Japan made by the Tokugawa shogunate in 1644, shows 39 large and small islands northeast of Hokkaido's Shiretoko Peninsula and Cape Nosappu . A Dutch expedition under Maarten Gerritsz Vries explored

232-531: A landscape. Only the southernmost island has large areas covered by trees, while more northerly islands have no trees, or spotty tree cover. The northernmost, Atlasov Island (Oyakoba in Japanese), is an almost-perfect volcanic cone rising sheer out of the sea; it has been praised by the Japanese in haiku , wood-block prints , and other forms, in much the same way as the better-known Mount Fuji . Its summit

290-440: A narrow arc some distance from the trench. The distance from the trench to the volcanic arc is greater for slabs subducting at a shallower angle, and this suggests that magma generation takes place when the slab reached a critical depth for the breakdown of an abundant hydrous mineral. This would produce an ascending "hydrous curtain" that accounts for focused volcanism along the volcanic arc. However, some models suggest that water

348-684: A popular domestic cat. Among terrestrial birds, ravens , peregrine falcons , some wrens and wagtails are common. The Ainu people inhabited the Kuril Islands from early times, although few records predate the 17th century. From the Kamakura period to the Muromachi period , there were Ezo (Ainu) people called Hinomoto from the Pacific coast of Hokkaido to the Kuril region, and Mr. Ando,

406-407: A principal component of the diet of many of the smaller marine mammals and birds along the chain. Fish : Further offshore, walleye pollock , Pacific cod , several species of flatfish are of the greatest commercial importance. During the 1980s, migratory Japanese sardine was one of the most abundant fish in the summer. Pinniped : The main pinnipeds were a significant object of harvest for

464-438: A rise in the demand of electricity, the local government is also upgrading a state-run geothermal power plant at Mount Baransky , an active volcano, where steam and hot water can be found. In 2022, a special economic zone was established on the Kuril islands with special tax regimes, exemption from corporate income tax, VAT with reduced customs duties for 20 years. It is an important part of Russian government's plan to develop

522-621: A shell be bent downwards by an angle of θ, without tearing or wrinkling, only on a circle whose radius is θ/2. This means that arcs where the subducting slab descends at a shallower angle will be more tightly curved. Prominent arcs whose slabs subduct at about 45 degrees, such as the Kuril Islands , the Aleutian Islands , and the Sunda Arc , have a radius of about 20 to 22 degrees. Volcanic arcs are divided into those in which

580-452: A subduction zone. The active front of a volcanic arc is the belt where volcanism develops at a given time. Active fronts may move over time (millions of years), changing their distance from the oceanic trench as well as their width. A volcanic arc is part of an arc-trench complex , which is the part of a subduction zone that is visible at the Earth's surface. A subduction zone is where

638-741: A volcanic archipelago administered as part of Sakhalin Oblast in the Russian Far East . The islands stretch approximately 1,300 km (810 mi) northeast from Hokkaido in Japan to Kamchatka Peninsula in Russia, separating the Sea of Okhotsk from the north Pacific Ocean . There are 56 islands and many minor islets. The Kuril Islands consist of the Greater Kuril Chain and, at

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696-416: Is a stub . You can help Misplaced Pages by expanding it . Volcanic arc Volcanic arcs are distinct from volcanic chains formed over hotspots in the middle of a tectonic plate. Volcanoes often form one after another as the plate moves over the hotspot, and so the volcanoes progress in age from one end of the chain to the other. The Hawaiian Islands form a typical hotspot chain, with the older islands to

754-408: Is continuously released from the slab from shallow depths down to 70 to 300 kilometers (43 to 186 mi), and much of the water released at shallow depths produces serpentinization of the overlying mantle wedge. According to one model, only about 18 to 37 percent of the water content is released at sufficient depth to produce arc magmatism. The volcanic arc is then interpreted as the depth at which

812-431: Is formed. Arc volcanism takes place where the slab descends out from under the cool shallow corner, allowing magma to be generated and rise through warmer, less stiff mantle rock. Magma may be generated over a broad area but become focused into a narrow volcanic arc by a permeability barrier at the base of the overriding plate. Numerical simulations suggest that crystallization of rising magma creates this barrier, causing

870-415: Is lost from the subducted plate when the temperature and pressure become sufficient to break down these minerals and release their water content. The water rises into the wedge of mantle overlying the slab and lowers the melting point of mantle rock to the point where magma is generated. While there is wide agreement on the general mechanism, research continues on the explanation for focused volcanism along

928-553: Is low in volcanic arc rocks. Because volcanic rock is easily weathered and eroded , older volcanic arcs are seen as plutonic rocks , the rocks that formed underneath the arc (e.g. the Sierra Nevada batholith ), or in the sedimentary record as lithic sandstones . Paired metamorphic belts , in which a belt of high-temperature, low-pressure metamorphism is located parallel to a belt of low-temperature, high-pressure metamorphism, preserve an ancient arc-trench complex in which

986-552: Is occupied by a nesting bird. Several of the islands, including Kunashir and the Lesser Kuril Chain in the South Kurils, and the northern Kurils from Urup to Paramushir, have been recognised as Important Bird Areas (IBAs) by BirdLife International because they support populations of various threatened bird species, including many waterbirds , seabirds and waders . The composition of terrestrial species on

1044-615: Is particularly characteristic of volcanic arcs, though it sometimes also occurs in regions of crustal extension. In the rock record, volcanic arcs can be recognized from their thick sequences of volcaniclastic rock (formed by explosive volcanism) interbedded with greywackes and mudstones and by their calc-alkaline composition. In more ancient rocks that have experienced metamorphism and alteration of their composition ( metasomatism ), calc-alkaline rocks can be distinguished by their content of trace elements that are little affected by alteration, such as chromium or titanium , whose content

1102-564: Is taken up by rodents , many introduced in historical times. The largest southernmost and northernmost islands are inhabited by brown bear , foxes, and martens . Leopards once inhabited the islands. Some species of deer are found on the more southerly islands. It is claimed that a wild cat, the Kurilian Bobtail , originates from the Kuril Islands. The bobtail is due to the mutation of a dominant gene. The cat has been domesticated and exported to nearby Russia and bred there, becoming

1160-694: Is the highest point in Sakhalin Oblast . Owing to their location along the Pacific shelf edge and the confluence of Okhotsk Sea gyre and the southward Oyashio Current , the Kuril islands are surrounded by waters that are among the most productive in the North Pacific, supporting a wide range and high abundance of marine life. Invertebrates : Extensive kelp beds surrounding almost every island provide crucial habitat for sea urchins , various mollusks and countless other invertebrates and their associated predators. Many species of squid provide

1218-477: Is the primary occupation. The islands have strategic and economic value, in terms of fisheries and also mineral deposits of pyrite , sulfur , and various polymetallic ores . There are hopes that oil exploration will provide an economic boost to the islands. In 2014, construction workers built a pier and a breakwater in Kitovy Bay, central Iturup, where barges are a major means of transport, sailing between

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1276-1701: The Habomai rocks, together called the Northern Territories . In addition, the Japanese government claims that the Kuril Islands, other than the Northern Territories and South Karafuto, are undetermined areas under international law because the San Francisco Peace Treaty does not specify where they belong and the Soviet Union has not signed it. On 8 February 2017 the Russian government gave names to five previously unnamed Kuril islands in Sakhalin Oblast : Derevyanko Island (after Kuzma Derevyanko , 43°22′8″N 146°1′3″E  /  43.36889°N 146.01750°E  / 43.36889; 146.01750 ), Gnechko Island (after Alexey Gnechko , 43°48′5″N 146°52′1″E  /  43.80139°N 146.86694°E  / 43.80139; 146.86694 ), Gromyko Island (after Andrei Gromyko , 46°14′1″N 150°36′1″E  /  46.23361°N 150.60028°E  / 46.23361; 150.60028 ), Farkhutdinov Island (after Igor Farkhutdinov , 43°48′5″N 146°53′2″E  /  43.80139°N 146.88389°E  / 43.80139; 146.88389 ) and Shchetinina Island (after Anna Shchetinina , 46°13′7″N 150°34′6″E  /  46.21861°N 150.56833°E  / 46.21861; 150.56833 ). As of 2013 , 19,400 people inhabited

1334-541: The Kamchatka-Kurile meadows and sparse forests , a larger ecoregion that extends onto the Kamchatka Peninsula and Commander Islands . Because of the generally smaller size and isolation of the central islands, few major terrestrial mammals have colonized these, though red and Arctic foxes were introduced for the sake of the fur trade in the 1880s. The bulk of the terrestrial mammal biomass

1392-548: The Kuril islands in return for entering the Pacific War against the Japanese during World War II. In August 1945 the Soviet Union mounted an armed invasion of South Sakhalin at the cost of over 5,000 Soviet and Japanese lives. The Kuril Islands are split into three administrative districts ( raions ), each a part of Sakhalin Oblast : Japan maintains a claim to the three islands of Kunashir , Iturup , and Shikotan , and

1450-812: The Russian far east . The main Russian force stationed on the islands is the 18th Machine Gun Artillery Division , which has its headquarters in Goryachiye Klyuchi on the Iturup Island. There are also Border Guard Service troops stationed on the islands. In February 2011, Russian President Dmitry Medvedev called for substantial reinforcements of the Kuril Islands defences. Subsequently, in 2015, additional anti-aircraft missile systems Tor and Buk , coastal defence missile system Bastion , Kamov Ka-52 combat helicopters and one Varshavyanka project submarine came on defence of Kuril Islands. During

1508-476: The subpolar oceanic climate of southwest Alaska much more than the hypercontinental climate of Manchuria and interior Siberia, as precipitation is heavy and permafrost completely absent. It is characterized by mild summers with only 1 to 3 months above 10 °C or 50 °F and cold, snowy, extremely windy winters below −3 °C or 26.6 °F, although usually above −10 °C or 14 °F. The chain ranges from temperate to sub-Arctic climate types, and

1566-478: The true seals and Steller sea lions has been relatively insignificant on the Kuril islands proper. Since the 1960s there has been essentially no additional harvest and the pinniped populations in the Kuril islands appear to be fairly healthy and in some cases expanding. The notable exception is the now extinct Japanese sea lion , which was known to occasionally haul out on the Kuril islands. Sea otters : Sea otters were exploited very heavily for their pelts in

1624-449: The 19th century, as shown by 19th- and 20th-century whaling catch and sighting records. Seabirds : The Kuril islands are home to many millions of seabirds, including northern fulmars , tufted puffins , murres , kittiwakes , guillemots , auklets , petrels , gulls and cormorants . On many of the smaller islands in summer, where terrestrial predators are absent, virtually every possibly hummock, cliff niche or underneath of boulder

1682-661: The 2022 Russian Invasion of Ukraine it was reported that parts of the 18th Machine Gun Artillery Division were redeployed to Eastern Ukraine. While in Russian sources the islands are mentioned for the first time in 1646, the earliest detailed information about them was provided by the explorer Vladimir Atlasov in 1697. In the 18th and early 19th centuries, the Kuril Islands were explored by Danila Antsiferov , I. Kozyrevsky, Ivan Yevreinov , Fyodor Luzhin , Martin Spanberg , Adam Johann von Krusenstern , Vasily Golovnin , and Henry James Snow. The following table lists information on

1740-769: The Ezo Sateshiku and Ezo Kanrei, was in charge of this ("Suwa Daimyojin Ekotoba"). It is said that when turmoil broke out on Ezogashima, he dispatched troops from Tsugaru. Its activities include the Kanto Gomensen, which calls itself the Ando Suigun, and is based in Jusanminato ("Kaisen Shikimoku"), supplying Japanese products to Ezo society and purchasing large quantities of northern products and shipping them nationwide. ("Thirteen Streets").The Matsumae clan,

1798-640: The Kuril Islands are known as the Chishima Islands ( Kanji : 千島列島 Chishima Rettō pronounced [tɕiɕima ɾeꜜttoː] , literally, 'Thousand Islands Archipelago'), also known as the Kuriru Islands ( Katakana : クリル列島 Kuriru Rettō [kɯɾiɾɯ ɾeꜜttoː] , literally, Kuril Archipelago ). Once the Russians reached the islands in the 18th century they found a pseudo-etymology from Russian kurit′ , курить 'to smoke' due to

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1856-410: The Kuril Islands, of which 16,700 lived on the four disputed southern islands and 2,600 lived on Paramushir , the northernmost large island; the islands in between are uninhabited. These include ethnic Russians , Ukrainians , Belarusians , Tatars , Nivkhs , Oroch , Japanese and Ainus . Iturup Island is over 60% ethnically Ukrainian. Russian Orthodox Christianity is the main religion. Some of

1914-620: The Kuril islands is dominated by Asian mainland taxa via migration from Hokkaido and Sakhalin Islands and by Kamchatkan taxa from the North. While highly diverse, there is a relatively low level of endemism on a species level. The WWF divides the Kuril Islands into two ecoregions . The southern Kurils, along with southwestern Sakhalin, comprise the South Sakhalin-Kurile mixed forests ecoregion. The northern islands are part of

1972-559: The Kuril islands. The Ainu were required to adopt Japanese names, and ordered to cease religious practices such as animal sacrifice and the custom of tattooing. Although not compulsory, education was conducted in Japanese. Prior to Japanese colonization (in 1868) about 100 Ainu reportedly lived on the Kuril islands. In February 1945 the Yalta Agreement promised to the Soviet Union South Sakhalin and

2030-867: The North Pacific, with the Aleutian Arc consisting of the Aleutian Islands and their extension the Aleutian Range on the Alaska Peninsula , and the Kuril–Kamchatka Arc comprising the Kuril Islands and southern Kamchatka Peninsula . Kuril Islands The Kuril Islands or Kurile Islands ( / ˈ k ( j ) ʊər ɪ l , k j ʊ ˈ r iː l / ; Russian : Кури́льские острова́ , romanized : Kuril'skiye ostrova , IPA: [kʊˈrʲilʲskʲɪjə ɐstrɐˈva] ; Japanese : Kuriru rettō ( クリル列島 , "Kuril Islands") or Chishima rettō ( 千島列島 , "Thousand Islands") ) are

2088-491: The bark Cape Horn Pigeon , of New Bedford and escorted it to Vladivostok , where it was detained for nearly two weeks. At the very end of the 19th century, the Japanese administration started the forced assimilation of the native Ainu people. Also at this time the Ainu were granted automatic Japanese citizenship, effectively denying them the status of an indigenous group. Many Japanese moved onto former Ainu lands, including

2146-714: The continual fumes and steam above the islands from volcanoes. The Kuril Islands form part of the ring of tectonic instability encircling the Pacific Ocean referred to as the Ring of Fire . The islands themselves are summits of stratovolcanoes that are a direct result of the subduction of the Pacific Plate under the Okhotsk Plate , which forms the Kuril Trench some 200 kilometres (124 mi) east of

2204-475: The cove and ships anchored offshore. A new road has been carved through the woods near Kurilsk, the island's biggest village, going to the site of Yuzhno-Kurilsk Mendeleyevo Airport . Gidrostroy, the Kurils' biggest business group with interests in fishing, construction and real estate, built its second fish processing factory on Iturup island in 2006, introducing a state-of-the-art conveyor system. To deal with

2262-695: The crust and magmatic underplating contribute to thickening of the crust. Volcanic arcs are characterized by explosive eruption of calc-alkaline magma, though young arcs sometimes erupt tholeiitic magma and a few arcs erupt alkaline magma. Calc-alkaline magma can be distinguished from tholeiitic magma, typical of mid-ocean ridges , by its higher aluminium and lower iron content and by its high content of large-ion lithophile elements, such as potassium , rubidium , caesium , strontium , or barium , relative to high-field-strength elements, such as zirconium , niobium , hafnium , rare-earth elements (REE), thorium , uranium , or tantalum . Andesite

2320-402: The degree of melting becomes great enough to allow the magma to separate from its source rock. It is now known that the subducting slab may be located anywhere from 60 to 173 kilometers (37 to 107 mi) below the volcanic arc, rather than a single characteristic depth of around 120 kilometers (75 mi), which requires more elaborate models of arc magmatism. For example, water released from

2378-497: The high-temperature, low-pressure belt corresponds to the volcanic arc. In a subduction zone , loss of water from the subducted slab induces partial melting of the overriding mantle and generates low-density, calc-alkaline magma that buoyantly rises to intrude and be extruded through the lithosphere of the overriding plate. Most of the water carried downwards by the slab is contained in hydrous (water-bearing) minerals, such as mica , amphibole , or serpentinite minerals. Water

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2436-472: The indigenous populations of the Kuril islands, both for food and materials such as skin and bone. The long-term fluctuations in the range and distribution of human settlements along the Kuril island presumably tracked the pinniped ranges. In historical times, fur seals were heavily exploited for their fur in the 19th and early 20th centuries and several of the largest reproductive rookeries, as on Raykoke island, were extirpated. In contrast, commercial harvest of

2494-410: The islands in 1643. Fedot Alekseyevich Popov sailing into the area c.  1649 . Russian Cossacks landed on Shumshu in 1711. American whaleships caught right whales off the islands between 1847 and 1892. Three of the ships were wrecked on the islands: two on Urup in 1855 and one on Makanrushi in 1856. In September 1892, north of Kunashir Island , a Russian schooner seized

2552-466: The islands include many kinds of beach and rocky shores, cliffs, wide rivers and fast gravelly streams, forests, grasslands, alpine tundra , crater lakes and peat bogs . The soils are generally productive, owing to the periodic influxes of volcanic ash and, in certain places, owing to significant enrichment by seabird guano . However, many of the steep, unconsolidated slopes are susceptible to landslides and newer volcanic activity can entirely denude

2610-403: The islands is generally severe, with long, cold, stormy winters and short and notoriously foggy summers. The average annual precipitation is 40 to 50 inches (1,020 to 1,270 mm), a large portion of which falls as snow. The Köppen climate classification of most of the Kurils is subarctic ( Dfc ), although Kunashir is humid continental ( Dfb ). However, the Kuril Islands' climate resembles

2668-447: The islands off the coast of Venezuela in the south. The Lesser Antilles Volcanic Arc includes 21 'active' volcanoes, notably Soufriere Hills on Montserrat ; Mount Pelée on Martinique ; La Grande Soufrière on Guadeloupe ; Soufrière Saint Vincent on Saint Vincent ; Mount Scenery on Saba ; and the submarine volcano Kick 'em Jenny which lies about 10 kilometres (5.4 nmi) north of Grenada . This volcanology article

2726-649: The islands. The chain has around 100 volcanoes, some 40 of which are active, and many hot springs and fumaroles . There is frequent seismic activity , including a magnitude 8.5 earthquake in 1963 and one of magnitude 8.3 recorded on November 15, 2006 , which resulted in tsunami waves up to 1.5 metres (5 ft) reaching the California coast. Raikoke Island, near the centre of the archipelago, has an active volcano which erupted again in June 2019, with emissions reaching 13,000 m (42,651 ft). The climate on

2784-486: The northwest and Hawaii Island itself, which is just 400,000 years old, at the southeast end of the chain over the hotspot. Volcanic arcs do not generally exhibit such a simple age-pattern. There are two types of volcanic arcs: In some situations, a single subduction zone may show both aspects along its length, as part of a plate subducts beneath a continent and part beneath adjacent oceanic crust. The Aleutian Islands and adjoining Alaskan Peninsula are an example of such

2842-415: The overriding plate is continental (Andean-type arcs) and those in which the overriding plate is oceanic (intraoceanic or primitive arcs). The crust beneath the arc is up to twice as thick as average continental or oceanic crust: The crust under Andean-type arcs is up to 80 kilometers (50 mi) thick, while the crust under intraoceanic arcs is 20 to 35 kilometers (12 to 22 mi) thick. Both shortening of

2900-433: The overriding plate over the point where the subducting plate reaches a depth of roughly 120 kilometres (75 mi) and is a zone of volcanic activity between 50 and 200 kilometers (31 and 124 mi) in width. The shape of a volcanic arc is typically convex towards the subducting plate. This is a consequence of the spherical geometry of the Earth. The subducting plate behaves like a flexible thin spherical shell, and such

2958-410: The released water lowers the melting point of the overlying mantle wedge enough for melting. The location of the volcanic arc may be determined by the presence of a cool shallow corner at the tip of the mantle wedge, where the mantle rock is cooled by both the overlying plate and the slab. Not only does the cool shallow corner suppress melting, but its high stiffness hinders the ascent of any magma that

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3016-634: The remaining magma to pool in a narrow band at the apex of the barrier. This narrow band corresponds to the overlying volcanic arc. Two classic examples of oceanic island arcs are the Mariana Islands in the western Pacific Ocean and the Lesser Antilles in the western Atlantic Ocean. The Cascade Volcanic Arc in western North America and the Andes along the western edge of South America are examples of continental volcanic arcs. The best examples of volcanic arcs with both sets of characteristics are in

3074-412: The slab at moderate depths might react with amphibole minerals in the lower part of the mantle wedge to produce water-rich chlorite . This chlorite-rich mantle rock is then dragged downwards by the subducting slab, and eventually breaks down to become the source of arc magmatism. The location of the arc depends on the angle and rate of subduction, which determine where hydrous minerals break down and where

3132-529: The southwest end, the parallel Lesser Kuril Chain . They cover an area of around 10,503.2 square kilometres (4,055.3 sq mi), with a population of roughly 20,000. The islands have been under Russian administration since their 1945 invasion by the Soviet Union near the end of World War II . Japan claims the four southernmost islands, including two of the three largest ( Iturup and Kunashir ), as part of its territory, as well as Shikotan and

3190-507: The subducting plate and the overriding plate coincides with a deep and narrow oceanic trench . This trench is created by the gravitational pull of the relatively dense subducting plate pulling the leading edge of the plate downward. Multiple earthquakes occur within the subducting slab with the seismic hypocenters located at increasing depth under the island arc: these quakes define the Wadati–Benioff zones . The volcanic arc forms on

3248-598: The unpopulated Habomai islets, which has led to the ongoing Kuril Islands dispute . The disputed islands are known in Japan as the country's "Northern Territories". The name Kuril originates from the autonym of the aboriginal Ainu , the islands' original inhabitants : kur , meaning 'man'. It may also be related to names for other islands that have traditionally been inhabited by the Ainu people , such as Kuyi or Kuye for Sakhalin and Kai for Hokkaidō . In Japanese ,

3306-418: The vegetative cover consequently ranges from tundra in the north to dense spruce and larch forests on the larger southern islands. The highest elevations on the islands are Alaid volcano (highest point: 2,339 m or 7,674 ft) on Atlasov Island at the northern end of the chain and Tyatya volcano (1,819 m or 5,968 ft) on Kunashir Island at the southern end. Landscape types and habitats on

3364-416: The villages are permanently occupied by Russian soldiers. Others are inhabited by civilians, who are mostly fishers, workers in fish factories, dockers, and social sphere workers (police, medics, teachers, etc.). Construction works on the islands have attracted migrant workers from the rest of Russia and other post-Soviet states . As of 2014 , there were only 8 inhabited islands out of a total of 56. Fishing

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