|Elevation||1,259 m (4,131 ft)|
|Age of rock||Pleistocene|
|Last eruption||March 1477|
Torfajökull (Icelandic for "Torfi's glacier"; [ˈtʰɔrvaˌjœːkʏtl̥] ) is a rhyolitic stratovolcano, caldera (central volcano) and complex of subglacial volcanoes, located north of Mýrdalsjökull and south of Þórisvatn Lake, Iceland. Torfajökull last erupted in 1477 and consists of the largest area of silicic extrusive rocks in Iceland.
The volcano's eruption around 870, a combined bimodal eruption (rhyolite-basalt) with additional engagement of the Bárðarbunga-Veiðivötn volcanic system, has left a thin layer of easily recognized mixed tephra all over Iceland (Landnámslag).This layer makes it possible to determine the exact dates of many archeological finds by so called tephrochronology, like in the Reykjavík 871±2 museum.
According to legend, the glacier is named for Torfi Jónsson í Klofa, an Icelandic historical figure. When the plague arrived in Iceland in 1493, Torfi fled with his family and his belongings into the highlands and settled in a valley surrounded by the glacier.
According to another legend, the glacier is named for Torfi, a farm worker at a nearby farm. Torfi eloped with the farmer's daughter and fled to the glacier.
Iceland is an island country at the confluence of the North Atlantic and Arctic oceans, east of Greenland and immediately south of the Arctic Circle, atop the constructive boundary of the northern Mid-Atlantic Ridge about 860 km (530 mi) from Scotland and 4,200 km (2,600 mi) from New York City. One of the world's most sparsely populated countries, Iceland's boundaries are almost the same as the main island – the world's 18th largest in area and possessing almost all of the country's area and population and also it is world's 9th largest island country. It is the westernmost European country and has more land covered by glaciers than in all of continental Europe. The total size is 103,125 km2 (39,817 sq mi). It has an Exclusive Economic Zone of 751,345 km2 (290,096 sq mi).
Volcanology is the study of volcanoes, lava, magma and related geological, geophysical and geochemical phenomena (volcanism). The term volcanology is derived from the Latin word vulcan. Vulcan was the ancient Roman god of fire.
The volcanoes of Iceland include a high concentration of active ones due to Iceland's location on the Mid-Atlantic Ridge, a divergent tectonic plate boundary, and its location over a hot spot.
Mýrdalsjökull is an ice cap in the south of Iceland. It is to the north of Vík í Mýrdal and to the east of the smaller ice cap Eyjafjallajökull. Between these two glaciers is Fimmvörðuháls pass. Its peak reaches 1,493 m (4,898 ft) in height and in the year 1980 it covered an area of approximately 595 km2 (230 sq mi).
Eyjafjallajökull is one of the smaller ice caps of Iceland, north of Skógar and west of Mýrdalsjökull. The ice cap covers the caldera of a volcano with a summit elevation of 1,651 metres (5,417 ft). The volcano has erupted relatively frequently since the Last Glacial Period, most recently in 2010, when, although relatively small for a volcanic eruption, it caused enormous disruption to air travel across western and northern Europe for a week.
For the volcanic landforms around Krýsuvík, see also: Krýsuvík
Öræfajökull, is an ice-covered volcano in south-east Iceland. The largest active volcano and the highest peak in Iceland at 2,110 metres (6,920 ft), it lies within the Vatnajökull National Park and is covered by the glacier.
Frostastaðavatn is a lake in Iceland. It is situated in the Highlands of Iceland, not far from the famous mountains of Landmannalaugar and the volcano Hekla.
Grímsvötn is a volcano with a fissure system located in Vatnajökull National Park, Iceland. The volcano itself is completely subglacial and located under the northwestern side of the Vatnajökull ice cap. The subglacial caldera is at, at an elevation of 1,725 m (5,659 ft). Beneath the caldera is the magma chamber of the Grímsvötn volcano.
Mount Hudson is a stratovolcano in southern Chile, and the site of one of the largest eruptions in the twentieth century. The mountain itself is covered by a glacier. There is a caldera at the summit from an ancient eruption; modern volcanic activity comes from inside the caldera. Mount Hudson is named after Francisco Hudson, a 19th-century Chilean Navy hydrographer.
Villarrica is one of Chile's most active volcanoes, rising above the lake and town of the same name, 750 km (470 mi) south of Santiago. It is also known as Rucapillán, a Mapuche word meaning "great spirit's house". It is the westernmost of three large stratovolcanoes that trend northwest to southeast obliquely perpendicular to the Andean chain along the Mocha-Villarrica Fault Zone, along with Quetrupillán and the Chilean portion of Lanín, are protected within Villarrica National Park. Guided ascents are popular during summer months.
A tuya is a type of distinctive, flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet. They are rare worldwide, being confined to regions which were covered by glaciers and had active volcanism during the same period.
The geology of Iceland is unique and of particular interest to geologists. Iceland lies on the divergent boundary between the Eurasian plate and the North American plate. It also lies above a hotspot, the Iceland plume. The plume is believed to have caused the formation of Iceland itself, the island first appearing over the ocean surface about 16 to 18 million years ago. The result is an island characterized by repeated volcanism and geothermal phenomena such as geysers.
Subglacial eruptions, those of ice-covered volcanoes, result in the interaction of magma with ice and snow, leading to meltwater formation, jökulhlaups, and lahars. Flooding associated with meltwater is a significant hazard in some volcanic areas, including Iceland, Alaska, and parts of the Andes. Jökulhlaups, glacial outburst floods, have been identified as the most frequently occurring volcanic hazard in Iceland, with major events where peak discharges can reach 10 000 – 100 000 m3/s occurring when there are large eruptions beneath glaciers.
Mocho-Choshuenco is a glacier covered compound stratovolcano in the Andes of Los Ríos Region, Chile. It is made of the twin volcanoes Choshuenco in the northwest and the Mocho in the southeast. The highest parts of the volcano are part of the Mocho-Choshuenco National Reserve while the eastern slopes are partly inside the Huilo-Huilo Natural Reserve.
Bárðarbunga, is a stratovolcano located under Vatnajökull in Vatnajökull National Park which is Iceland's most extensive glacier. The second highest mountain in Iceland, 2,009 metres (6,591 ft) above sea level, Bárðarbunga is also part of a volcanic system that is approximately 200 kilometres (120 mi) long and 25 kilometres (16 mi) wide.
Tindfjallajökull is a stratovolcano in the south of Iceland. It has erupted rocks of basaltic to rhyolitic composition, and a 5-km-wide caldera was formed during the eruption of the 54,000-year-old Thórsmörk Ignimbrite. It is capped by a glacier of 19 km². Its highest peak is Ýmir (1462m), which takes its name from the giant Ýmir of Norse mythology. The most recent eruption was at an unknown time in the Holocene.
The 2010 eruptions of Eyjafjallajökull were a period of volcanic events at Eyjafjallajökull in Iceland which, although relatively small for volcanic eruptions, caused enormous disruption to air travel across western and northern Europe over an initial period of six days in April 2010. Additional localised disruption continued into May 2010, and eruptive activity persisted until June 2010. The eruption was declared officially over in October 2010, after 3 months of inactivity, when snow on the glacier did not melt. From 14–20 April, ash from the volcanic eruption covered large areas of Northern Europe. About 20 countries closed their airspace to commercial jet traffic and it affected approximately 10 million travellers.
The Reykjanes Peninsula in southwest Iceland is the continuation of the mostly submarine Reykjanes Ridge, a part of the Mid-Atlantic Ridge, on land and reaching from Esja in the north and Hengill in the east to Reykjanestá in the west. Suðurnes is an administrative unit covering part of Reykjanes Peninsula.
Gjálp is a hyaloclastite ridge (tindar) in Iceland under the Vatnajökull glacier shield. It originated in an eruption series in 1996 and is probably part of the Grímsvötn volcanic system, though not all the scientists involved are of this opinion.