Portal:Volcanoes
The Volcanoes portal
On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most 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 in the 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 the 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, Mercury has pyroclastic deposits formed by explosive volcanic activity. (Full article...)
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.png) The volcano-caldera complex in the north of Lombok |
In 1257, a catastrophic eruption occurred at the Samalas volcano on the Indonesian island of Lombok. The event had a probable Volcanic Explosivity Index of 7, making it one of the largest volcanic eruptions during the current Holocene epoch. It left behind a large caldera that contains Lake Segara Anak. Later volcanic activity created more volcanic centres in the caldera, including the Barujari cone, which remains active.
The event created eruption columns reaching tens of kilometres into the atmosphere and pyroclastic flows that buried much of Lombok and crossed the sea to reach the neighbouring island of Sumbawa. The flows destroyed human habitations, including the city of Pamatan, which was the capital of a kingdom on Lombok. Ash from the eruption fell as far as 340 kilometres (210 mi) away in Java; the volcano deposited more than 10 cubic kilometres (2.4 cu mi) of rocks and ash. (Full article...)Did you know
- ...that the 1980 Mount St. Helens eruption (pictured) in Washington was the first major volcanic eruption to occur in the U.S. since the 1915 eruption of Lassen Peak in California?
- ...that the evolution of Hawaiian volcanoes ends with the Guyot Stage, and that most, if not all, the volcanoes west of Kure Atoll are guyots?
- ...that the Irazú Volcano in Costa Rica erupted violently in 1963, on the day U.S. President John F. Kennedy arrived in the country for a state visit?
- ...that Ferdinandea was a volcanic island near Sicily which was claimed by four countries when it appeared in 1831, but was destroyed by erosion less than a year later?
- ...that the Iceland hotspot is partly responsible for the frequent volcanic eruptions and geothermal activity experienced in Iceland?
- ...that the only active volcano in South Asia is on Barren Island, one of India's Andaman Islands?
- ...that Imbabura is an inactive stratovolcano in northern Ecuador which is revered in local folklore as a protective parent?
- ..that one submarine volcano located in Banda Sea of Indonesia is called the Emperor of China?
General images
Cross-section through a stratovolcano (vertical scale is exaggerated):(from Volcanism)- Large magma chamber
- Bedrock
- Conduit (pipe)
- Base
- Sill
- Dike
- Layers of ash emitted by the volcano
- Flank
- Layers of lava emitted by the volcano
- Throat
- Parasitic cone
- Lava flow
- Vent
- Crater
- Ash cloud
Diagram of a Vulcanian eruption. (key: 1. Ash plume 2. Lapilli 3. Lava fountain 4. Volcanic ash rain 5. Volcanic bomb 6. Lava flow 7. Layers of lava and ash 8. Stratum 9. Sill 10. Magma conduit 11. Magma chamber 12. Dike) Click for larger version. (from Types of volcanic eruptions)
Galeras, Nariño, (Colombia). (from Decade Volcanoes)
Mount Lamington following the devastating 1951 eruption (from Types of volcanic eruptions)
Tavurvur in Papua New Guinea erupting (from Types of volcanic eruptions)
Distribution of selected hotspots. The numbers in the figure are related to the listed hotspots on Hotspot (geology). (from Timeline of volcanism on Earth)
Diagram of a Surtseyan eruption. (key: 1. Water vapor cloud 2. Compressed ash 3. Crater 4. Water 5. Layers of lava and ash 6. Stratum 7. Magma conduit 8. Magma chamber 9. Dike) Click for larger version. (from Types of volcanic eruptions)
Plate tectonics map with volcano locations indicated with red circles (from Volcanism)
2016 eruption of Mount Sinabung (from Types of volcanic eruptions)
Satellite measurements of ash and aerosol emissions from Mount Pinatubo. (from Timeline of volcanism on Earth)
Diagram of a Hawaiian eruption. (key: 1. Ash plume 2. Lava fountain 3. Crater 4. Lava lake 5. Fumaroles 6. Lava flow 7. Layers of lava and ash 8. Stratum 9. Sill 10. Magma conduit 11. Magma chamber 12. Dike) Click for larger version. (from Types of volcanic eruptions)
Teide, Tenerife (Spain). (from Decade Volcanoes)
Sulfur dioxide emissions by volcanoes. Mount Pinatubo: 20 million tons of sulfur dioxide. (from Timeline of volcanism on Earth)
TOMS sulfur dioxide from the June 15, 1991 eruption of Mount Pinatubo. (from Timeline of volcanism on Earth)
VEI and ejecta volume correlation (from Timeline of volcanism on Earth)
The final eruptions in the creation of Banks Peninsula in New Zealand occurred about 9 million years ago. (from Timeline of volcanism on Earth)
NASA, Global Dimming - El Chichon, VEI 5; Pinatubo, VEI 6. (from Timeline of volcanism on Earth)
Diagram of a Strombolian eruption. (key: 1. Ash plume 2. Lapilli 3. Volcanic ash rain 4. Lava fountain 5. Volcanic bomb 6. Lava flow 7. Layers of lava and ash 8. Stratum 9. Dike 10. Magma conduit 11. Magma chamber 12. Sill) Click for larger version. (from Types of volcanic eruptions)
Location of Mount Pinatubo, showing area over which ash from the 1991 eruption fell. (from Timeline of volcanism on Earth)
Diagram showing the scale of VEI correlation with total ejecta volume (from Types of volcanic eruptions)
Colima Volcano eruption column, December 2016 (from Decade Volcanoes)
Pyroclastic flows at Mayon Volcano, Philippines, 1984 (from Types of volcanic eruptions)
Lava-flooded craters and large expanses of smooth volcanic plains on Mercury (from List of extraterrestrial volcanoes)
Herðubreið, a tuya in Iceland (from Types of volcanic eruptions)
The lava spine that developed after the 1902 eruption of Mount Pelée (from Types of volcanic eruptions)
Phreatic explosion captured at the Main Crater of Taal Volcano. Photo taken from the installed IP camera of the Philippine Institute of Volcanology and Seismology (PHIVOLCS) monitoring the volcano. (from Decade Volcanoes)
A major eruption of Gran Canaria took place around 14 million years ago. (from Timeline of volcanism on Earth)
Some of the eruptive structures formed during volcanic activity (counterclockwise): a Plinian eruption column, Hawaiian pahoehoe flows, and a lava arc from a Strombolian eruption (from Types of volcanic eruptions)
A diagram of a Subglacial eruption. (key: 1. Water vapor cloud 2. Crater lake 3. Ice 4. Layers of lava and ash 5. Stratum 6. Pillow lava 7. Magma conduit 8. Magma chamber 9. Dike) Click for larger version. (from Types of volcanic eruptions)
Diagram of a phreatic eruption. (key: 1. Water vapor cloud 2. Magma conduit 3. Layers of lava and ash 4. Stratum 5. Water table 6. Explosion 7. Magma chamber) (from Types of volcanic eruptions)
Diagram of a Submarine eruption. (key: 1. Water vapor cloud 2. Water 3. Stratum 4. Lava flow 5. Magma conduit 6. Magma chamber 7. Dike 8. Pillow lava) Click to enlarge. (from Types of volcanic eruptions)
An example of the lava arcs formed during Strombolian activity. This image is of Stromboli itself. (from Types of volcanic eruptions)
Ropey pahoehoe lava from Kilauea, Hawaiʻi (from Types of volcanic eruptions)
Sarychev Peak: the sulphur dioxide cloud generated by the eruption on June 12, 2009 (in Dobson units). (from Timeline of volcanism on Earth)
Building destroyed by eruptions at Mount Unzen, Japan (from Decade Volcanoes)
Diagram of Peléan eruption. (key: 1. Ash plume 2. Volcanic ash rain 3. Lava dome 4. Volcanic bomb 5. Pyroclastic flow 6. Layers of lava and ash 7. Stratum 8. Magma conduit 9. Magma chamber 10. Dike) Click for larger version. (from Types of volcanic eruptions)
Diagram of a Plinian eruption. (key: 1. Ash plume 2. Magma conduit 3. Volcanic ash rain 4. Layers of lava and ash 5. Stratum 6. Magma chamber) Click for larger version. (from Types of volcanic eruptions)
Lahar flows from the 1985 eruption of Nevado del Ruiz, which totally destroyed Armero in Colombia (from Types of volcanic eruptions)
MLO transmission ratio - Solar radiation reduction due to volcanic eruptions (from Timeline of volcanism on Earth)
21 April 1990 eruptive column from Redoubt Volcano, as viewed to the west from the Kenai Peninsula (from Types of volcanic eruptions)
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Selected picture
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An arching fountain of pāhoehoe lava, approximately 10 m (33 ft) high, issuing from a spatter cone of Pu‘u Kahaualea, Hawaii. Pāhoehoe is basaltic lava that has a smooth, billowy, undulating, or ropy surface. These surface features are due to the movement of very fluid lava under a congealing surface crust. Pāhoehoe lavas typically have a temperature of 1100°C–1200°C.
Selected quote
"This ground is hot enough to cook the Sunday roast!"
— John Seach, remarking on his boots melting whilst on the slope of Lopevi Volcano, 2000
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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.
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- 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.
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