![]() Many Holocene volcanic events are known from Iceland, including 17 eruptions of Hekla from the Southern Volcanic zone. Detailed geophysical studies have shown that magma episodically rises from depth into magma chambers located a few miles (kilometers) below the surface, then dikes intrude the overlying crust and flow horizontally for tens of miles to accommodate crustal extension of several to several tens of feet over several hundred years. ![]() Hydrothermal activity is intense along the fracture zones, with diffuse faulting and volcanic activity merging into a narrow zone within a few kilometers depth beneath the surface. Active spreading occurs along a series of 5-60-mile (8-100 km) long zones of fissures, graben, and dike swarms, with basaltic and rhyolitic volcanoes rising from central parts of fissures. These ridge jumps have caused the active spreading to propagate into regions of older crust that have been remelted, forming alkalic and even silicic volcanic rocks deposited unconformably over older tholeiitic basalts. Spreading is offset from the oceanic Kolbeinsey ridge by the dextral Tjornes fracture zone off the island's northern coast.ĭuring the past 6 million years the Iceland hot spot has drifted toward the southeast relative to the north Atlantic, and the oceanic ridge system has made a succession of small jumps so that active spreading has remained coincident with the plume of hottest, weakest mantle material. Iceland Seismic zone, then continues north through the Eastern Rift zone. Active spreading is transferred to the Southern Volcanic zone across a transform fault called the South The oceanic Reykjanes ridge and sinistral transform south of the island rises to the surface and continues as the Western Rift zone. The mid-Atlantic ridge crosses the island from southwest to northeast and has a spreading rate 1.2 inches per year (3 cm/yr), with the mean extension oriented toward an azimuth (compass direction) of 103 degrees east of north. Iceland has an average elevation of more than 1,600 feet (500 m), and owes its elevation to a hot spot interacting with the midocean ridge system beneath the island. The resultant cloud of volcanic ash brought major disruption to air travel across Europe.The mid-Atlantic ridge rises above sea level on the North Atlantic island of Iceland, lying 178 miles (287 km) off the coast of Greenland and 495 miles (800 km) from the coast of Scotland. Further eruptions on 14 April forced hundreds of people to abandon their homes. On 21 March 2010, a volcano in Eyjafjallajökull in the south of Iceland erupted for the first time since 1821, forcing 600 people to flee their homes. Only scientists researching the growth of new life are allowed to visit the island. Named after Surtr, it rose above the ocean in a series of volcanic eruptions between 8 November 1963 and 5 June 1968. Surtsey, one of the youngest islands in the world, is part of Iceland. Iceland has hundreds of volcanoes within approx. Iceland, however, has a variety of volcanic types (composite and fissure), many producing more evolved lavas such as rhyolite and andesite. ![]() The island itself is composed primarily of basalt, a low-silica lava associated with effusive volcanism as has occurred also in Hawaii. 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. Geysir has since then grown quieter and does not erupt often. After a phase of inactivity, Geysir started erupting again after a series of earthquakes in 2000. Iceland has many geysers, including Geysir, from which the English word is derived, and the famous Strokkur, which erupts every 5–10 minutes.
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