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Portal:Volcanoes

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The Volcanoes portal

Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station, May 2006

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.

Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature; the melted particles then adhere to the turbine blades and alter their shape, disrupting the operation of the turbine. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere (or troposphere); however, they also absorb heat radiated from the Earth, thereby warming the upper atmosphere (or stratosphere). Historically, volcanic winters have caused catastrophic famines.

Selected article

Nevado del Ruiz, two weeks after its deadly 1985 eruption
Nevado del Ruiz, also known as El Mesa de Herveo or Kumanday, is the northernmost volcano of the Andean Volcanic Belt, lying about 129 kilometers (80 mi) west of Bogotá in the Tolima Department of Colombia. It is a stratovolcano, composed of many layers of lava alternating with hardened volcanic ash and other pyroclastic rocks. Nevado del Ruiz has been active for about two million years, since the early Pleistocene or late Pliocene epoch, with three major eruptive periods. The current volcanic cone formed during the "present" eruptive period, which began 150 thousand years ago.

Nevado del Ruiz usually generates Plinian eruptions, which produce swift-moving currents of hot gas and rock called pyroclastic flows. These eruptions often cause massive lahars (mud and debris flows), which pose a threat to human life and the environment. On November 13, 1985, a small eruption produced an enormous lahar that buried and desolated the town of Armero in Tolima Department, causing an estimated 23,000 deaths. This event later became known as the Armero tragedy—the deadliest lahar in recorded history. Similar but less deadly incidents occurred in 1595 and 1845, consisting of a small explosive eruption followed by a large lahar.


Selected biography

Sir William Hamilton
Sir William Hamilton, KB, PC (13 December 1730 – 6 April 1803) was a Scottish diplomat, antiquarian, archaeologist and vulcanologist. Hamilton was the fourth son of Lord Archibald Hamilton, governor of Jamaica. He was commissioned into the 3rd Foot Guards in 1747 and was promoted Lieutenant in 1753.

Hamilton was Britain's ambassador to the court of Naples from 1764 - 1800. During this time he studied local volcanic activity and earthquakes, and wrote a book on the ancient Roman city of Pompeii. He collected Greek vases and other antiquities, selling part of his collection to the British Museum in 1772. A small part of his second collection went down with HMS Colossus while being transported to Britain in 1798. The surviving part of the second collection was catalogued for sale at auction at Christie's when at the eleventh hour Thomas Hope stepped in and purchased the remains of Hamilton's second collection of mostly South Italian vases.

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Bathymetry of the Galápados hotspot

Volcanoes topics

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Core topics: Volcano  • Volcanology  • Igneous petrology  • Lava  • Magma  • Decade Volcanoes  • List of volcanoes  • Plate tectonics  • Hotspot

Types of volcanoes: Fissure vent  • Shield volcano  • Lava dome  • Cinder cone  • Stratovolcano  • Supervolcano  • Submarine volcano  • Subglacial volcano  • Mud volcano

Types of eruptions: (Overview)  • Strombolian  • Vulcanian  • Peléan  • Hawaiian  • Surtseyan  • Plinian  • Submarine  • Subglacial  • Phreatic

Related portals

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Grand Prismatic Spring
Credit: Jim Peaco, National Park Service

Aerial view of Grand Prismatic Spring in Yellowstone National Park. The spring is approximately 250 ft (76 m) by 300 ft (91 m) in size. The deep azure blue water in the center is sterile, and surrounded by a huge mat of algae and bacteria. The orange color is from the carotenoids they produce.

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"We'll just look at you. If you looked scared then we'll panic."

— Discovery channel crew, talking to volcanologist John Seach during filming at Yasur Volcano, 2000.

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Project collaboration

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The current Project collaboration is Mount Shasta.

The project collaboration is a drive to improve our coverage of an important volcano-related topic. Once the article has been improved significantly, a new collaboration is chosen. Please improve the article any way you can.

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Things you can do
  • 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.


Featured work and other approved content

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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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