In geology , a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics . Typical rift features are a central linear downfaulted depression, called a graben , or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley , which may be filled by water forming a rift lake . The axis of the rift area may contain volcanic rocks , and active volcanism is a part of many, but not all, active rift systems.
81-703: Fjölnir ( Icelandic pronunciation: [ˈfjœlnɪr̥] ) was an Icelandic -language journal published annually in Copenhagen from 1835 to 1847. The journal was founded by the Fjölnismenn (literally, "men of Fjölnir"), four young Icelandic intellectuals who sought to revive national consciousness in Iceland in the hopes of raising support for Icelandic independence . They were Jónas Hallgrímsson , Konráð Gíslason , Brynjólfur Pétursson and Tómas Sæmundsson . All four were Icelanders who had studied at Bessastaðir and
162-449: A lacustrine environment or in a restricted marine environment, although not all rifts contain such sequences. Reservoir rocks may be developed in pre-rift, syn-rift and post-rift sequences. Effective regional seals may be present within the post-rift sequence if mudstones or evaporites are deposited. Just over half of estimated oil reserves are found associated with rifts containing marine syn-rift and post-rift sequences, just under
243-557: A longhouse in Stöðvarfjörður that may date to as early as 800. Swedish Viking explorer Garðar Svavarsson was the first to circumnavigate Iceland in 870 and establish that it was an island. He stayed during the winter and built a house in Húsavík . Garðar departed the following summer, but one of his men, Náttfari , decided to stay behind with two slaves. Náttfari settled in what is now known as Náttfaravík, and he and his slaves became
324-414: A shield volcano with a magma chamber underneath). Several classifications of the systems exist, for example there is one of 30 systems, and one of 34 systems, with the later currently being used in Iceland itself. The climate of Iceland's coast is subarctic . The warm North Atlantic Current ensures generally higher annual temperatures than in most places of similar latitude in the world. Regions in
405-528: A summit in Reykjavík in 1986 between United States President Ronald Reagan and Soviet Premier Mikhail Gorbachev , during which they took significant steps towards nuclear disarmament . A few years later, Iceland became the first country to recognise the independence of Estonia , Latvia , and Lithuania as they broke away from the USSR. Throughout the 1990s, the country expanded its international role and developed
486-444: A 32 percent increase in Iceland's gross national income between 2002 and 2007. In 2003–2007, following the privatisation of the banking sector under the government of Davíð Oddsson , Iceland moved towards having an economy based on international investment banking and financial services. It was quickly becoming one of the most prosperous countries in the world, but was hit hard by a major financial crisis . The crisis resulted in
567-634: A convicted child sex offender. Snap elections in October 2017 brought to power a new coalition consisting of the Independence Party, the Progressive Party, and the Left-Green Movement , headed by Katrín Jakobsdóttir . After the 2021 parliamentary election , the new government was, just like the previous government, a tri-party coalition of the Independence Party, the Progressive Party, and
648-636: A defence agreement was signed with the United States. American troops returned to Iceland as the Iceland Defence Force and remained throughout the Cold War . The US withdrew the last of its forces on 30 September 2006. Iceland prospered during the Second World War. The immediate post-war period was followed by substantial economic growth , driven by the industrialisation of the fishing industry and
729-480: A dominantly half-graben geometry, controlled by a single basin-bounding fault. Segment lengths vary between rifts, depending on the elastic thickness of the lithosphere. Areas of thick colder lithosphere, such as the Baikal Rift have segment lengths in excess of 80 km, while in areas of warmer thin lithosphere, segment lengths may be less than 30 km. Along the axis of the rift the position, and in some cases
810-460: A famine that killed nearly a quarter of the island's population. In addition, the eruption caused dust clouds and haze to appear over most of Europe and parts of Asia and Africa for several months afterwards, and affected climates in other areas. Iceland has many geysers , including Geysir , from which the English word is derived, and the famous Strokkur , which erupts every 8–10 minutes. After
891-589: A foreign policy orientated towards humanitarian and peacekeeping causes. To that end, Iceland provided aid and expertise to various NATO-led interventions in Bosnia , Kosovo , and Iraq . Iceland joined the European Economic Area in 1994, after which the economy was greatly diversified and liberalised. International economic relations increased further after 2001 when Iceland's newly deregulated banks began to raise great amounts of external debt , contributing to
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#1732851260757972-704: A fully sovereign and independent state in a personal union with Denmark. The Government of Iceland established an embassy in Copenhagen and requested that Denmark carry out on its behalf certain defence and foreign affairs matters, subject to consultation with the Althing. Danish embassies around the world displayed two coats of arms and two flags: those of the Kingdom of Denmark and those of the Kingdom of Iceland . Iceland's legal position became comparable to those of countries belonging to
1053-403: A kind of orogeneses in extensional settings, which is referred as to rifting orogeny. Once rifting ceases, the mantle beneath the rift cools and this is accompanied by a broad area of post-rift subsidence. The amount of subsidence is directly related to the amount of thinning during the rifting phase calculated as the beta factor (initial crustal thickness divided by final crustal thickness), but
1134-710: A latitude just south of the Arctic Circle . Its latitude and marine influence keep summers chilly, and most of its islands have a polar climate . According to the ancient manuscript Landnámabók , the settlement of Iceland began in 874 AD, when the Norwegian chieftain Ingólfr Arnarson became the island's first permanent settler. In the following centuries, Norwegians , and to a lesser extent other Scandinavians , immigrated to Iceland, bringing with them thralls (i.e., slaves or serfs) of Gaelic origin. The island
1215-466: A low- silica lava associated with effusive volcanism as has occurred also in Hawaii . Iceland, however, has a variety of volcanic types (composite and fissure), many producing more evolved lavas such as rhyolite and andesite . Iceland has hundreds of volcanoes with about 30 active volcanic systems. Surtsey , one of the youngest islands in the world, is part of Iceland. Named after Surtr , it rose above
1296-438: A mid-oceanic ridge and a set of conjugate margins separated by an oceanic basin. Rifting may be active, and controlled by mantle convection . It may also be passive, and driven by far-field tectonic forces that stretch the lithosphere. Margin architecture develops due to spatial and temporal relationships between extensional deformation phases. Margin segmentation eventually leads to the formation of rift domains with variations of
1377-406: A phase of inactivity, Geysir started erupting again after a series of earthquakes in 2000 . Geysir has since grown quieter and does not erupt often. With the widespread availability of geothermal power and the harnessing of many rivers and waterfalls for hydroelectricity , most residents have access to inexpensive hot water, heating, and electricity. The island is composed primarily of basalt ,
1458-620: A popular holiday destination. In 2016, Prime Minister Sigmundur Davíð Gunnlaugsson resigned after being implicated in the Panama Papers scandal. Early elections in 2016 resulted in a right-wing coalition government of the Independence Party , the Reform Party and Bright Future . This government fell when Bright Future quit the coalition due to a scandal involving then-Prime Minister Bjarni Benediktsson 's father's letter of support for
1539-429: A republic in 1944, ending the remaining formal ties to Denmark. Although the Althing was suspended from 1799 to 1845, Iceland nevertheless has a claim to sustaining one of the world's longest-running parliaments. Until the 20th century, Iceland relied largely on subsistence fishing and agriculture. Industrialization of the fisheries and Marshall Plan aid after World War II brought prosperity, and Iceland became one of
1620-699: A simple relay ramp at the overlap between two major faults of the same polarity, to zones of high structural complexity, particularly where the segments have opposite polarity. Accommodation zones may be located where older crustal structures intersect the rift axis. In the Gulf of Suez rift, the Zaafarana accommodation zone is located where a shear zone in the Arabian-Nubian Shield meets the rift. Rift flanks or shoulders are elevated areas around rifts. Rift shoulders are typically about 70 km wide. Contrary to what
1701-479: A society where subsistence depended almost entirely on agriculture. The Black Death swept Iceland twice, first in 1402–1404 and again in 1494–1495. The former outbreak killed 50% to 60% of the population, and the latter 30% to 50%. Around the middle of the 16th century, as part of the Protestant Reformation , King Christian III of Denmark began to impose Lutheranism on all his subjects. Jón Arason ,
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#17328512607571782-596: Is a Nordic island country between the North Atlantic and Arctic Oceans , on the Mid-Atlantic Ridge between North America and Europe . It is culturally and politically linked with Europe and is the region's westernmost and most sparsely populated country . Its capital and largest city is Reykjavík , which is home to about 36% of the country's roughly 380,000 residents (excluding nearby towns/suburbs which are separate municipalities). The official language of
1863-553: Is a sitka spruce planted in 1949 in Kirkjubæjarklaustur ; it was measured at 25.2 m (83 ft) in 2013. Algae such as Chondrus crispus , Phyllphora truncata and Phyllophora crispa and others have been recorded from Iceland. The only native land mammal when humans arrived was the Arctic fox , which came to the island at the end of the ice age, walking over the frozen sea. On rare occasions, bats have been carried to
1944-402: Is also affected by the degree to which the rift basin is filled at each stage, due to the greater density of sediments in contrast to water. The simple 'McKenzie model' of rifting, which considers the rifting stage to be instantaneous, provides a good first order estimate of the amount of crustal thinning from observations of the amount of post-rift subsidence. This has generally been replaced by
2025-496: Is also where most settlements are situated. The island's interior, the Highlands of Iceland , is a cold and uninhabitable combination of sand, mountains, and lava fields . The major towns are the capital city of Reykjavík , along with its outlying towns of Kópavogur , Hafnarfjörður , and Garðabær , nearby Reykjanesbær where the international airport is located, and the town of Akureyri in northern Iceland. The island of Grímsey on
2106-456: Is closer to continental Europe than to mainland North America, although it is closest to Greenland (290 kilometres; 155 nautical miles), an island of North America. Iceland is generally included in Europe for geographical, historical, political, cultural, linguistic and practical reasons. Geologically, the island includes parts of both continental plates. The closest bodies of land in Europe are
2187-505: Is difficult to determine the political influence of the volumes but that there can be little doubt that the volumes made a clear contribution to Icelandic poetry. This article about a literary magazine published in Europe is a stub . You can help Misplaced Pages by expanding it . See tips for writing articles about magazines . Further suggestions might be found on the article's talk page . Iceland Iceland ( Icelandic : Ísland , pronounced [ˈistlant] )
2268-420: Is low compared with other countries (over one million species have been described worldwide). Iceland is essentially free of mosquitoes . Rift Major rifts occur along the central axis of most mid-ocean ridges , where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates . Failed rifts are the result of continental rifting that failed to continue to
2349-513: Is the surface expression of the Iceland Plateau , a large igneous province forming as a result of volcanism from the Iceland hotspot and along the Mid-Atlantic Ridge , the latter of which runs right through it. This means that the island is highly geologically active with many volcanoes including Hekla , Eldgjá , Herðubreið , and Eldfell . The volcanic eruption of Laki in 1783–1784 caused
2430-456: The Boreal Kingdom . Plantlife consists mainly of grassland, which is regularly grazed by livestock. The most common tree native to Iceland is the northern birch ( Betula pubescens ), which formerly formed forests over much of Iceland, along with aspens ( Populus tremula ), rowans ( Sorbus aucuparia ), common junipers ( Juniperus communis ), and other smaller trees, mainly willows. When
2511-583: The Faroe Islands (420 km; 225 nmi); Jan Mayen Island (570 km; 310 nmi); Shetland and the Outer Hebrides , both about 740 km (400 nmi); and the Scottish mainland and Orkney , both about 750 km (405 nmi). The nearest part of Continental Europe is mainland Norway, about 970 km (525 nmi) away, while mainland North America is 2,070 km (1,120 nmi) away, at
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2592-582: The Little Ice Age , and overgrazing by sheep imported by settlers caused a loss of critical topsoil due to erosion . Today, many farms have been abandoned. Three-quarters of Iceland's 100,000 square kilometres (39,000 sq mi) is affected by soil erosion; 18,000 km (6,900 sq mi) is affected to a degree serious enough to make the land useless. Only a few small birch stands now exist in isolated reserves. The Icelandic Forest Service and other forestry groups promote large-scale reforestation in
2673-524: The Mid-Atlantic Ridge , a ridge along which the oceanic crust spreads and forms new crust. This part of the mid-ocean ridge is located above a mantle plume, causing Iceland to be subaerial (above the surface of the sea). The ridge marks the boundary between the Eurasian and North American Plates , and Iceland was created by rifting and accretion through volcanism along the ridge. Many fjords punctuate Iceland's 4,970-km-long (3,088-mi) coastline, which
2754-469: The Moho topography, including proximal domain with fault-rotated crustal blocks, necking zone with thinning of crustal basement , distal domain with deep sag basins, ocean-continent transition and oceanic domain. Deformation and magmatism interact during rift evolution. Magma-rich and magma-poor rifted margins may be formed. Magma-rich margins include major volcanic features. Globally, volcanic margins represent
2835-686: The Treaty of Kiel formally ceded Iceland to Denmark in 1814. Influenced by ideals of nationalism after the French Revolution , Iceland's struggle for independence took form and culminated in the Danish–Icelandic Act of Union in 1918, with the establishment of the Kingdom of Iceland , sharing through a personal union the incumbent monarch of Denmark . During the occupation of Denmark in World War II, Iceland voted overwhelmingly to become
2916-672: The University of Copenhagen . They all contributed to the publication of the journal until 1838. The fifth annual copy was published and paid for by Tómas Sæmundsson , who had moved back to Iceland, and had it printed in Viðey . Publication then ceased for a few years, as Jónas Hallgrímsson was occupied with his scientific research. A new issue was published in 1843, but at this point two societies, Fjölnisfélagið and Nokkrir Íslendingar , had taken over publication, led first by Gísli Magnússon and later by Halldór Kr. Friðriksson . The last issue of
2997-456: The Vestmannaeyjar archipelago. Lakes and glaciers cover 14.3% of its surface; only 23% is vegetated. The largest lakes are Þórisvatn reservoir: 83–88 km (32–34 sq mi) and Þingvallavatn : 82 km (32 sq mi); other important lakes include Lagarfljót and Mývatn . Jökulsárlón is the deepest lake, at 248 m (814 ft). Geologically, Iceland is part of
3078-645: The 'flexural cantilever model', which takes into account the geometry of the rift faults and the flexural isostasy of the upper part of the crust. Some rifts show a complex and prolonged history of rifting, with several distinct phases. The North Sea rift shows evidence of several separate rift phases from the Permian through to the Earliest Cretaceous , a period of over 100 million years. Rifting may lead to continental breakup and formation of oceanic basins. Successful rifting leads to seafloor spreading along
3159-609: The 1850s under the leadership of Jón Sigurðsson , based on the burgeoning Icelandic nationalism inspired by the Fjölnismenn and other Danish-educated Icelandic intellectuals. In 1874, Denmark granted Iceland a constitution and limited home rule. This was expanded in 1904, and Hannes Hafstein served as the first Minister for Iceland in the Danish cabinet. The Danish–Icelandic Act of Union , an agreement with Denmark signed on 1 December 1918 and valid for 25 years, recognised Iceland as
3240-607: The Arctic Circle contains the northernmost habitation of Iceland, whereas Kolbeinsey contains the northernmost point of Iceland. Iceland has three national parks : Vatnajökull National Park , Snæfellsjökull National Park , and Þingvellir National Park . The country is considered a "strong performer" in environmental protection, having been ranked 13th in Yale University 's Environmental Performance Index of 2012. A geologically young land at 16 to 18 million years old, Iceland
3321-625: The Commonwealth of Nations, such as Canada, whose sovereign is King Charles III . During World War II, Iceland joined Denmark in asserting neutrality. After the German occupation of Denmark on 9 April 1940, the Althing replaced the King with a regent and declared that the Icelandic government would take control of its own defence and foreign affairs. A month later, British armed forces conducted Operation Fork ,
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3402-677: The Left-Green Movement, headed by Prime Minister Katrín Jakobsdóttir. In April 2024, Bjarni Benediktsson of the Independence party succeeded Katrín Jakobsdóttir as prime minister. Iceland is at the juncture of the North Atlantic and Arctic Oceans. The main island is entirely south of the Arctic Circle , which passes through the small Icelandic island of Grímsey off the main island's northern coast. The country lies between latitudes 63 and 68°N , and longitudes 25 and 13°W . Iceland
3483-680: The US Marshall Plan programme, through which Icelanders received the most aid per capita of any European country (at US$ 209, with the war-ravaged Netherlands a distant second at US$ 109). Vigdís Finnbogadóttir assumed Iceland's presidency on 1 August 1980, making her the first elected female head of state in the world. The 1970s were marked by the Cod Wars —several disputes with the United Kingdom over Iceland's extension of its fishing limits to 200 nmi (370 km) offshore. Iceland hosted
3564-457: The country is Icelandic . Iceland is on a rift between tectonic plates , and its geologic activity includes geysers and frequent volcanic eruptions . The interior consists of a volcanic plateau with sand and lava fields , mountains and glaciers , and many glacial rivers flow to the sea through the lowlands . Iceland is warmed by the Gulf Stream and has a temperate climate , despite
3645-566: The country's climate continued to grow colder, resulting in mass emigration to the New World , particularly to the region of Gimli , Manitoba in Canada, which was sometimes referred to as New Iceland . About 15,000 people emigrated, out of a total population of 70,000. A national consciousness arose in the first half of the 19th century, inspired by romantic and nationalist ideas from mainland Europe. An Icelandic independence movement took shape in
3726-416: The country's total exports. Birds, especially seabirds, are an important part of Iceland's animal life. Atlantic puffins , skuas , and black-legged kittiwakes nest on its sea cliffs. Commercial whaling is practised intermittently along with scientific whale hunts. Whale watching has become an important part of Iceland's economy since 1997. Around 1,300 species of insects are known in Iceland. This
3807-417: The country. Due to the reforestation efforts, the forest cover of Iceland increased six-fold since the 1990s. This helps to offset carbon emissions, prevent sand storms and increase the productivity of farms. The planting of new forests has increased the number of trees, but the result does not compare to the original forests. Some of the planted forests include introduced species . The tallest tree in Iceland
3888-469: The development of isolated basins. In subaerial rifts, for example, drainage at the onset of rifting is generally internal, with no element of through drainage. As the rift evolves, some of the individual fault segments grow, eventually becoming linked together to form the larger bounding faults. Subsequent extension becomes concentrated on these faults. The longer faults and wider fault spacing leads to more continuous areas of fault-related subsidence along
3969-513: The eruption, known as the Mist Hardships ( Icelandic : Móðuharðindin ), over half of all livestock in the country died. Around a quarter of the population starved to death in the ensuing famine . In 1814, following the Napoleonic Wars , Denmark-Norway was broken up into two separate kingdoms via the Treaty of Kiel , but Iceland remained a Danish dependency. Throughout the 19th century,
4050-570: The events known locally as the Turkish Abductions , in which hundreds of residents were taken into slavery in North Africa and dozens killed; this was the only invasion in Icelandic history to have casualties. The 1707–08 Iceland smallpox epidemic is estimated to have killed a quarter to a third of the population. In 1783 the Laki volcano erupted, with devastating effects. In the years following
4131-464: The first permanent residents of Iceland to be documented. The Norwegian-Norse chieftain Ingólfr Arnarson built his homestead in present-day Reykjavík in 874. Ingólfr was followed by many other emigrant settlers, largely Scandinavians and their thralls , many of whom were Irish or Scottish . By 930, most arable land on the island had been claimed; the Althing , a legislative and judicial assembly
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#17328512607574212-463: The greatest migration from Iceland since 1887, with a net emigration of 5,000 people in 2009. Iceland's economy stabilised under the government of Jóhanna Sigurðardóttir and grew by 1.6% in 2012. The centre-right Independence Party was returned to power in coalition with the Progressive Party in the 2013 election. In the following years, Iceland saw a surge in tourism as the country became
4293-476: The invasion and occupation of the country, violating Icelandic neutrality . In 1941, the Government of Iceland, friendly to Britain, invited the then-neutral United States to take over its defence so that Britain could use its troops elsewhere. On 31 December 1943, the Danish–Icelandic Act of Union expired after 25 years. Beginning on 20 May 1944, Icelanders voted in a four-day plebiscite on whether to terminate
4374-523: The island was first settled, it was extensively forested, with around 30% of the land covered in trees. In the late 12th century, Ari the Wise described it in the Íslendingabók as "forested from mountain to sea shore". Permanent human settlement greatly disturbed the isolated ecosystem of thin, volcanic soils and limited species diversity . The forests were heavily exploited over the centuries for firewood and timber. Deforestation , climatic deterioration during
4455-440: The island was then called Garðarshólmur, which means "Garðar's Isle". Then came a Viking named Flóki Vilgerðarson ; his daughter drowned en route, then his livestock starved to death. The sagas say that the rather despondent Flóki climbed a mountain and saw a fjord ( Arnarfjörður ) full of icebergs, which led him to give the island its new and present name. The notion that Iceland's Viking settlers chose that name to discourage
4536-604: The island with the winds, but they are not able to breed there. No native or free-living reptiles or amphibians are on the island. The animals of Iceland include the Icelandic sheep , cattle , chickens , goats , the sturdy Icelandic horse , and the Icelandic Sheepdog , all descendants of animals imported by Europeans. Wild mammals include the Arctic fox, mink , mice, rats, rabbits, and reindeer . Polar bears occasionally visit
4617-415: The island, travelling from Greenland on icebergs, but no Icelandic populations exist. In June 2008, two polar bears arrived in the same month. Marine mammals include the grey seal ( Halichoerus grypus ) and harbour seal ( Phoca vitulina ). Many species of fish live in the ocean waters surrounding Iceland, and the fishing industry is a major part of Iceland's economy, accounting for roughly half of
4698-532: The journal was published in 1847. It was dedicated to the memory of Jónas Hallgrímsson , who had died in the spring of 1845. There is no evidence of the distribution numbers of the first few volumes but in the years 1843-1845, 300-400 copies of volumes 6-8 were sold in Iceland and Denmark. The volumes were most likely read aloud in large gatherings and loaned from farm to farm. Fjölnir introduced romanticism in Icelandic literature and poetry, and many of Jónas Hallgrímsson 's romantic poems were first published in
4779-479: The journal. It also spearheaded the revival of national and linguistic consciousness in Iceland. Fjölnir received a mixed reception among the Icelandic reading public, partly due to eccentric spelling conventions, and the perceived arrogance of the young Fjölnismenn . Nevertheless, it made important contributions to the revival of Icelandic as a written language, and greatly influenced the cultural and political milieu in Iceland. Historian Gunnar Karlsson finds that it
4860-437: The last Catholic bishop of Hólar , was beheaded in 1550 along with two of his sons. The country subsequently became officially Lutheran, and Lutheranism has since remained the dominant religion. In the 17th and 18th centuries, Denmark imposed harsh trade restrictions on Iceland. Natural disasters, including volcanic eruptions and disease, contributed to a decreasing population. In the summer of 1627, Barbary Pirates committed
4941-567: The majority of passive continental margins. Magma-starved rifted margins are affected by large-scale faulting and crustal hyperextension. As a consequence, upper mantle peridotites and gabbros are commonly exposed and serpentinized along extensional detachments at the seafloor. Many rifts are the sites of at least minor magmatic activity , particularly in the early stages of rifting. Alkali basalts and bimodal volcanism are common products of rift-related magmatism. Recent studies indicate that post-collisional granites in collisional orogens are
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#17328512607575022-472: The northeastern hinterland. The temperature records for Reykjavík are 26.2 °C (79.2 °F) on 30 July 2008, and −24.5 °C (−12.1 °F) on 21 January 1918. The entire country is in a single ecoregion , the Iceland boreal birch forests and alpine tundra . Some areas are covered by glaciers . Phytogeographically , Iceland belongs to the Arctic province of the Circumboreal Region within
5103-410: The northern tip of Labrador . Iceland is the world's 18th-largest island , and Europe's second-largest island after Great Britain and before Ireland. The main island covers 101,826 km (39,315 sq mi), but the entire country is 103,000 km (40,000 sq mi) in size, of which 62.7% is tundra . Iceland contains about 30 minor islands, including the lightly populated Grímsey and
5184-401: The ocean in a series of volcanic eruptions between 8 November 1963 and 5 June 1968. Only scientists researching the growth of new life are allowed to visit the island. The country has around 30 active volcanic systems. Within each are volcano-tectonic fissure systems and many, but not all of them, also have at least one central volcano (mostly in the form of a stratovolcano , sometimes of
5265-507: The personal union with Denmark, abolish the monarchy, and establish a republic. The vote was 97% to end the union, and 95% in favour of the new republican constitution. Iceland formally became a republic on 17 June 1944, with Sveinn Björnsson as its first president. In 1946, the US Defence Force Allied left Iceland. The nation formally became a member of NATO on 30 March 1949, amid domestic controversy and riots . On 5 May 1951,
5346-422: The point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot . Two of these evolve to the point of seafloor spreading, while the third ultimately fails, becoming an aulacogen . Most rifts consist of a series of separate segments that together form the linear zone characteristic of rifts. The individual rift segments have
5427-399: The polarity (the dip direction), of the main rift bounding fault changes from segment to segment. Segment boundaries often have a more complex structure and generally cross the rift axis at a high angle. These segment boundary zones accommodate the differences in fault displacement between the segments and are therefore known as accommodation zones. Accommodation zones take various forms, from
5508-404: The product of rifting magmatism at converged plate margins. The sedimentary rocks associated with continental rifts host important deposits of both minerals and hydrocarbons . SedEx mineral deposits are found mainly in continental rift settings. They form within post-rift sequences when hydrothermal fluids associated with magmatic activity are expelled at the seabed. Continental rifts are
5589-480: The rift axis. Significant uplift of the rift shoulders develops at this stage, strongly influencing drainage and sedimentation in the rift basins. During the climax of lithospheric rifting, as the crust is thinned, the Earth's surface subsides and the Moho becomes correspondingly raised. At the same time, the mantle lithosphere becomes thinned, causing a rise of the top of the asthenosphere. This brings high heat flow from
5670-621: The settlement of their verdant isle is most likely a myth. According to both Landnámabók and Íslendingabók , monks known as the Papar lived in Iceland before Scandinavian settlers arrived, possibly members of a Hiberno-Scottish mission . An archaeological excavation has revealed the ruins of a cabin in Hafnir on the Reykjanes peninsula . Carbon dating indicates that it was abandoned sometime between 770 and 880. In 2016, archaeologists uncovered
5751-651: The signing of the Old Covenant in 1262, which ended the Commonwealth and brought Iceland under the Norwegian crown. Possession of Iceland passed from the Kingdom of Norway (872–1397) to the Kalmar Union in 1415, when the kingdoms of Norway, Denmark, and Sweden were united. After the break-up of the union in 1523, it remained a Norwegian dependency, as a part of Denmark–Norway . Infertile soil, volcanic eruptions, deforestation, and an unforgiving climate made for harsh life in
5832-510: The sites of significant oil and gas accumulations, such as the Viking Graben and the Gulf of Suez Rift . Thirty percent of giant oil and gas fields are found within such a setting. In 1999 it was estimated that there were 200 billion barrels of recoverable oil reserves hosted in rifts. Source rocks are often developed within the sediments filling the active rift ( syn-rift ), forming either in
5913-470: The smallest population of any NATO member and is the only one with no standing army , possessing only a lightly armed coast guard . The Sagas of Icelanders say that a Norwegian named Naddodd (or Naddador) was the first Norseman to reach Iceland; in the ninth century, he named it Snæland or "Snowland" because it was snowing. Following Naddodd, the Swede Garðar Svavarsson arrived, and so
5994-463: The south coast is warmer, wetter, and windier than the north. The Central Highlands are the coldest part of the country. Low-lying inland areas in the north are the aridest. Snowfall in winter is more common in the north than in the south. The highest air temperature recorded was 30.5 °C (86.9 °F) on 22 June 1939 at Teigarhorn on the southeastern coast. The lowest was −38 °C (−36.4 °F) on 22 January 1918 at Grímsstaðir and Möðrudalur in
6075-491: The upwelling asthenosphere into the thinning lithosphere, heating the orogenic lithosphere for dehydration melting, typically causing extreme metamorphism at high thermal gradients of greater than 30 °C. The metamorphic products are high to ultrahigh temperature granulites and their associated migmatite and granites in collisional orogens, with possible emplacement of metamorphic core complexes in continental rift zones but oceanic core complexes in spreading ridges. This leads to
6156-534: The world with similar climates include the Aleutian Islands , the Alaska Peninsula , and Tierra del Fuego , although these regions are closer to the equator. Despite its proximity to the Arctic, the island's coasts remain ice-free through the winter. Ice incursions are rare, with the last having occurred on the north coast in 1969. The climate varies between different parts of the island. Generally speaking,
6237-680: The world's wealthiest and most developed nations. In 1994 it became a part of the European Economic Area , further diversifying its economy into sectors such as finance, biotechnology, and manufacturing . Iceland has a market economy with relatively low taxes , compared to other OECD countries, as well as the highest trade union membership in the world . It maintains a Nordic social welfare system that provides universal health care and tertiary education . Iceland ranks highly in international comparisons of national performance, such as quality of life, education, protection of civil liberties, government transparency, and economic freedom. It has
6318-507: Was adopted by consensus around 999–1000, although Norse paganism persisted among segments of the population for some years afterward. The Icelandic Commonwealth lasted until the 13th century when the political system devised by the original settlers proved unable to cope with the increasing power of Icelandic chieftains. The internal struggles and civil strife of the Age of the Sturlungs led to
6399-493: Was governed as an independent commonwealth under the native parliament, the Althing , one of the world's oldest functioning legislative assemblies. After a period of civil strife , Iceland acceded to Norwegian rule in the 13th century. In 1397, Iceland followed Norway's integration into the Kalmar Union along with the kingdoms of Denmark and Sweden, coming under de facto Danish rule upon its dissolution in 1523. The Danish kingdom introduced Lutheranism by force in 1550, and
6480-539: Was initiated to regulate the Icelandic Commonwealth . The lack of arable land also served as an impetus to the settlement of Greenland starting in 986. The period of these early settlements coincided with the Medieval Warm Period , when temperatures were similar to those of the early 20th century. At this time about 25% of Iceland was covered with forest, compared to 1% in the present day. Christianity
6561-530: Was previously thought, elevated passive continental margins (EPCM) such as the Brazilian Highlands , the Scandinavian Mountains and India's Western Ghats , are not rift shoulders. The formation of rift basins and strain localization reflects rift maturity. At the onset of rifting, the upper part of the lithosphere starts to extend on a series of initially unconnected normal faults , leading to
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