Portal:Volcanoes

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edit   The Volcanoes Portal A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Violent explosive eruptions from such vents often produce craters or calderas and coat extensive areas in volcanic ash, while the lava from comparatively gentle effusive eruptions may eventually form large plains, cones or mountains. Volcanoes are generally found where tectonic plates are pulled apart or come together. A mid-oceanic ridge, such as the Mid-Atlantic Ridge, hosts volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire contains many volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are not commonly created at transform boundaries, where two tectonic plates slide past one another. Volcanoes can be caused by mantle plumes. The resulting hotspots, for example at Hawaii, can occur far from plate boundaries. Hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons. Intraplate volcanoes can also form where there is stretching and thinning of the Earth's crust, as in the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes. More about volcanoes... Show new selections edit   Selected article The 1980 eruption of Mount St. Helens, a volcano located in Washington state, in the United States, was a major volcanic eruption. The eruption was the most significant to occur in the contiguous 48 U.S. states (VEI = 5, 0.3 cu mi, 1.2 km3 of material erupted), in terms of power and volume of material released, since the 1915 eruption of California's Lassen Peak. The eruption was preceded by a two-month series of earthquakes and steam-venting episodes, caused by an injection of magma at shallow depth below the mountain that created a huge bulge and a fracture system on Mount St. Helens' north slope. An earthquake at 8:32 a.m. on May 18, 1980, caused the entire weakened north face to slide away, suddenly exposing the partly molten, gas- and steam-rich rock in the volcano to lower pressure. The rock responded by exploding into a very hot mix of pulverized lava and older rock that sped toward Spirit Lake so fast that it quickly passed the avalanching north face. A volcanic ash column rose high into the atmosphere and deposited ash in 11 U.S. states. At the same time, snow, ice, and several entire glaciers on the mountain melted, forming a series of large lahars (volcanic mudslides) that reached as far as the Columbia River, nearly fifty miles (eighty kilometers) to the south. Less severe outbursts continued into the next day only to be followed by other large but not as destructive eruptions later in 1980. ...Archive/Nominations Read more... edit   Selected biography Howel Williams (1898-1980) was a noted American geologist and volcanologist. He was born of Welsh parents in Liverpool, England, on October 12, 1898. He received a BA in geography in 1923 and an MA in archaeology in 1924 from Liverpool University. He studied geology at the Imperial College of Science and Technology in London. In 1926 he moved to the University of California at Berkeley in 1926. In 1928 he was awarded the degree of D.Sc. from the University of Liverpool and published his first papers on the geology of various California volcanic regions. He published many studies on the volcanoes of California, but is most noted for his "The Geology of Crater Lake National Park" in which he recognized the nature of the collapse of the crater and extended the work to develop the principles of volcanic caldera formation. He did extensive early work on the geology of Central America (often sketch-mapping from the windows of second-class buses), and of the Galapagos Islands. In Latin America, Williams put to good use his early background in archeology. For instance, he used petrographic techniques to trace the origin of stone used in the giant Olmec sculptures of La Venta, Tabasco Mexico. ...Archive/Nominations Read more... edit   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? ...Archive/Nominations More... edit   Volcanoes news News 4 June 2011: An eruption occurs on Puyehue, Chile. 21 May 2011: Grímsvötn, in Iceland, erupts, disrupting European air travel. 19 February 2011: Mount Etna in Italy erupts for the second time this year. The event is of Stromobolian-type activity. 17 February 2011: Earthquake activity occurs at Mount St. Helens, USA. The earthquake swarms occurred in the same area as those preceding St. Helen's famous 1980 eruption. No actions have yet taken place. 26 January 2011: An eruption has occurred at Kirishima, Japan, causing some residents of the area to evacuate. ...Archive More... edit   Volcanoes topics 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 edit   Related portals Earth sciences Seamounts Geography Atmospheric sciences edit   Selected picture Credit: J.D. Griggs, USGS 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. ...Archive/Nominations Read more... edit   Selected quote "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 anniversery of its eruption, 2 May 2009 ...Archive More... edit   Project collaboration 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. edit   WikiProjects WikiProject Volcanoes WikiProject Seamounts WikiProject Mountains edit   Categories [−] Volcanoes [×] Lists of volcanoes [+] Volcanoes by continent [+] Volcanoes by country [+] Volcanoes by highest known Volcanic Explosivity Index of eruption [+] Volcanoes by status [+] Atolls [+] Complex volcanoes [+] Decade Volcanoes [+] Diatremes [+] Extraterrestrial volcanoes [×] Fissure vents [+] Hotspot volcanoes [+] Volcanic islands [+] Lava domes [×] Mud volcanoes [×] Parasitic cones [+] Polygenetic volcanoes [×] Pyroclastic shields [+] Ridge volcanoes [×] Rift volcanoes [+] Shield volcanoes [+] Stratovolcanoes [+] Subduction volcanoes [×] Subglacial mounds [+] Subglacial volcanoes [+] Submarine volcanoes [+] Supervolcanoes [+] Volcanic belts [+] Volcanic calderas [+] Volcanic cones [+] Volcanic craters [+] Volcanic fields [+] Volcanic groups [×] Volcanic Seven Summits [+] Volcanoes by geochronology [−] Volcanology [×] Volcanologists [+] Basalt [+] Hotspots [+] Hydrothermal vents [×] Monogenetic volcanoes [×] Parasitic cones [+] Polygenetic volcanoes [×] Tephra [+] Volcanic belts [×] Volcanic eruption types [+] Volcanic events [+] Volcanic groups [+] Volcanic landforms [+] Volcanic rocks [+] Volcanism [×] Volcano observatories [+] Volcanoes [×] Volcanology stubs edit   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. edit   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)  • 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 42 volcano-related Featured pictures. A full gallery can be seen here. Good articles: Abyssal plain  • Amak Volcano  • Anahim hotspot  • 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  • Roxy Ann Peak  • Rùm  • Sakurajima  • 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. edit   Associated Wikimedia Volcanoes on Wikibooks  Volcanoes on Wikimedia Commons Volcanoes on Wikinews  Volcanoes on Wikiquote  Volcanoes on Wikisource  Volcanoes on Wikiversity  Volcanoes on Wiktionary  Manuals and books Images and media News Quotations Texts Learning resources Definitions What are portals? · List of portals · Featured portals