The Volcanoes portal
On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean 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, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, 3,000 kilometers (1,900 mi) deep within Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide past one another.
Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool Earth's troposphere. Historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines.
Other planets besides Earth have volcanoes. For example, volcanoes are very numerous on Venus. In 2009, a paper was published suggesting a new definition for the word ‘volcano’ that includes processes such as cryovolcanism. It suggested that a volcano be defined as ‘an opening on a planet or moon’s surface from which magma, as defined for that body, and/or magmatic gas is erupted.’
This article mainly covers volcanoes on Earth. See § Volcanoes on other celestial bodies and Cryovolcano for more information. (Full article...)
Selected article -
Volcanism on Io, a moon of Jupiter, is represented by the presence of volcanoes, volcanic pits and lava flows on the surface. Io's volcanic activity was discovered in 1979 by Linda Morabito, an imaging scientist working on Voyager 1. Observations of Io by passing spacecraft and Earth-based astronomers have revealed more than 150 active volcanoes. , up to 400 such volcanoes are predicted to exist based on these observations.[outdated statistic] Io's volcanism makes the satellite one of only four known currently volcanically or cryovolcanically active worlds in the Solar System (the others being Earth, Saturn's moon Enceladus, and Neptune's moon Triton.)
First predicted shortly before the Voyager 1 flyby, the heat source for Io's volcanism comes from tidal heating produced by its forced orbital eccentricity. This differs from Earth's internal heating, which is derived primarily from radioactive isotope decay and primordial heat of accretion. Io's eccentric orbit leads to a slight difference in Jupiter's gravitational pull on the satellite between its closest and farthest points on its orbit, causing a varying tidal bulge. This variation in the shape of Io causes frictional heating in its interior. Without this tidal heating, Io might have been similar to the Moon, a world of similar size and mass, geologically dead and covered with numerous impact craters. (Full article...)Did you know
- ... that the Galápagos hotspot (pictured), located in the east Pacific Ocean, is responsible for the creation of the Galápagos Islands?
- ... that although the summit of submarine volcano Lōʻihi is 969 metres (3,180 ft) below sea level, it is still twice as tall, measured from the base of its southern flank, as Mount St. Helens ever was?
- ... that a sub-marine eruption near the Hunga Tonga-Hunga Haʻapai volcano in Tonga began spewing steam, smoke, pumice, and ash thousands of feet into the sky on March 16, 2009?
- ... that Cross Seamount, a landform arising from the ocean floor southwest of Hawaii, is used by the NOAA to study tuna migratory patterns?
- ... that Detroit Seamount, a submarine volcano in the North Pacific, is as big as the island of Hawaii?
- ... that Koko Guyot, a submarine volcano in the Hawaiian volcanic chain, was named for the 58th emperor of Japan, Emperor Kōkō?
- ... that the discovery of a population of Aleutian cackling geese on Buldir Volcano in the Aleutian Islands prevented their extinction?
- ... that the 1929 eruption of the Gareloi Volcano created a fissure running down the mountain's southern summit?
General images
Selected biography -
Harry Glicken (March 7, 1958 – June 3, 1991) was an American volcanologist. He researched Mount St. Helens in the United States before and after its 1980 eruption, and was very distraught about the death of volcanologist David A. Johnston, who was Glicken's mentor and supervisor in Spring 1980 at Mount St. Helens. Glicken was initially assigned to the USGS observation post in the weeks leading up to the eruption but was called away the night before the eruption.
In 1991, while conducting avalanche research on Mount Unzen in Japan, Glicken and fellow volcanologists Katia and Maurice Krafft were killed by a pyroclastic flow. His remains were found four days later and were cremated in accordance with his parents' request. Glicken and Johnston remain the only American volcanologists known to have died in volcanic eruptions.
Despite a long-term interest in working for the United States Geological Survey, Glicken never received a permanent post there because there was a hiring freeze for federal agencies when he graduated with his PhD. While conducting research from sponsorships granted by the National Science Foundation and other organizations, Glicken accrued expertise in the field of volcanic debris avalanches. He also wrote several major publications on the topic, including his doctoral dissertation based on his research at Mount St. Helens titled "Rockslide-debris Avalanche of May 18, 1980, Mount St. Helens Volcano, Washington" that initiated widespread interest in the phenomenon. (Full article...)Selected picture
An October 2002 eruption of Mount Etna, a volcano on the Italian island of Sicily, as seen from the International Space Station. Etna is the largest of Italy's three active volcanoes and one of the most active in the world. This eruption, one of Etna's most vigorous in years, was triggered by a series of earthquakes. Ashfall was reported as far away as Libya, 600 km (373 mi) to the south.
Selected quote
"No one told us we needed a gas mask."
— Tourist visiting the highly active Ambrym volcano, South West Pacific.
Related portals
WikiProjects
Volcanoes topics
Subcategories
Featured work and other approved content
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) • Kamaʻehuakanaloa 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.
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.
What 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.
Associated Wikimedia
The following Wikimedia Foundation sister projects provide more on this subject:
-
Commons
Free media repository -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikinews
Free-content news -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikiversity
Free learning tools -
Wiktionary
Dictionary and thesaurus