Portal:Volcanoes

The Volcanoes portal

Sabancaya volcano erupting, Peru in 2017

A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.

Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle. Therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, e.g., in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Volcanoes are usually not created where two tectonic plates slide past one another.

Large eruptions can affect ambient temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's troposphere; historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines.

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Calabozos is a Holocene caldera in central Chile's Maule Region (7th Region). Part of the Chilean Andes' volcanic segment, it is considered a member of the Southern Volcanic Zone (SVZ), one of the three distinct volcanic belts of South America. This most active section of the Andes runs along central Chile's western edge, and includes more than 70 of Chile's stratovolcanoes and volcanic fields. Calabozos lies in an extremely remote area of poorly glaciated mountains.

Calabozos and the majority of the Andean volcanoes formed from the subduction of the oceanic Nazca Plate under the continental South American continental lithosphere. The caldera is in a transitional region between thick and thin lithosphere, and is probably supplied by a pool of andesitic and rhyolitic magma. It sits on a historic bed of volcanic and plutonic sedimentary rock (rock formed within the Earth) that in turn sits on top of a layer of merged sedimentary and metamorphic rock. Read more...

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Carmelo Formation at Point Lobos

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"El enemigo sigue ahí. (The enemy is still there)"

— Sergio Galilea, intendant of the Los Lagos Region, Chile, speaking of the Chaitén Volcano on the first anniversary of its eruption, 2 May 2009


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George Julius Poulett Scrope

George Julius Poulett Scrope FRS (10 March 1797 – 19 January 1876) was an English geologist and political economist as well as a magistrate for Stroud in Gloucestershire.

He was the second son of J. Poulett Thompson of Waverley Abbey, Surrey. He was educated at Harrow, and for a short time at Pembroke College, Oxford, but in 1816 he entered St John's College, Cambridge, graduating BA in 1821. Through the influence of Edward Clarke and Adam Sedgwick he became interested in mineralogy and geology.

During the winter of 1816–1817 he was at Naples, and was so keenly interested in Vesuvius that he renewed his studies of the volcano in 1818; and in the following year visited Etna and the Lipari Islands. In 1821 he married the daughter and heiress of William Scrope of Castle Combe, Wiltshire, and assumed her name; and he entered the House of Commons of the United Kingdom in 1833 as MP for Stroud, retaining his seat until 1868. Read more...

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Moais on Easter Island
Credit: Artemio Urbina

Volcanic tuff (consolidated ash) is a common building material. Most of the Moais on Easter Island were built with tholeiitic basalt tuff.

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Featured articles: 1980 eruption of Mount St. Helens  • 2007–2008 Nazko earthquakes  • Amchitka  • Armero tragedy  • Craters of the Moon National Monument and Preserve  • Cerro Azul (Chile volcano)  • David A. Johnston  • Enceladus (moon)  • Geology of the Lassen volcanic area  • Io (moon)  • Loihi Seamount  • Mauna Kea  • Mauna Loa  • Metacomet Ridge  • Mono-Inyo Craters  • Mount Cayley volcanic field  • Mount St. Helens  • Mount Tambora  • Nevado del Ruiz  • Surtsey  • The Volcano (British Columbia)  • Triton (moon)  • Upper and Lower Table Rock  • Volcanism on Io  • Volcano (South Park)  • Yellowstone National Park

Featured lists: List of volcanoes in Indonesia  • List of volcanoes in the Hawaiian – Emperor seamount chain  • List of largest volcanic eruptions

Featured pictures: There are currently 43 volcano-related Featured pictures. A full gallery can be seen here.

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Good articles: Abyssal plain  • Amak Volcano  • Anahim hotspot  • Axial Seamount  • Ben Nevis  • Bowie Seamount  • Crater Lake  • Davidson Seamount  • Ferdinandea  • Gareloi Volcano  • Geyser  • Glacier Peak  • Hawaii hotspot  • Hualālai  • Kohala (mountain)  • Lake Toba  • Minoan eruption  • Mount Adams (Washington)  • Mount Bailey  • Mount Baker  • Mount Cleveland (Alaska)  • Mount Edziza volcanic complex  • Mount Garibaldi  • Mount Hood  • Mount Kenya  • Mount Rainier  • Mount Redoubt  • Mount Tehama  • Mount Thielsen  • Mount Vesuvius  • Peter I Island  • Roxy Ann Peak  • Rùm  • Sakurajima  • Sangay  • Silverthrone Caldera  • Staffa  • Types of volcanic eruptions  • Volcanic ash  • Weh Island  • Wells Gray-Clearwater volcanic field  • Yamsay Mountain

Valued pictures: A gallery of volcano-related valued pictures can be seen here.

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  • Add the {{WikiProject Volcanoes}} message box to talk pages of articles within the scope of this project, including appropriate assessments, if needed.
  • Add appropriate volcano type categories to articles, and verify the accuracy of any existing categories. See the section "Categorization" below.
  • Add {{infobox mountain}} to articles if needed and missing, and add volcano-related fields to existing infoboxes if these are missing.
  • Expand volcano articles which are stubs, especially by adding photos and (most importantly) proper references.
  • Help improve articles related to Hawaiian and Canadian volcanism by joining the Hawaiian and Canadian workgroups.
  • Improve some of the project's most visible articles.


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