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Supervolcanoes
A supervolcano is a volcano that has had an eruption with a Volcanic Explosivity Index (VEI) of 8, the largest recorded value on the index. This means the volume of deposits for such an eruption is greater than 1,000 cubic kilometers (240 cubic miles). Supervolcanoes occur when magma in the mantle rises into the crust but is unable to break through it. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure and ruptures. This can occur at hotspots (for example, Yellowstone Caldera) or at subduction zones (for example, Toba). Large-volume supervolcanic eruptions are also often associated with large igneous provinces, which can cover huge areas with lava and volcanic ash. These can cause long-lasting climate change (such as the triggering of a small ice age) and threaten species with extinction. The Oruanui eruption of New Zealand's Taupō Volcano (about 26,500 years ago) was the world's most recent VEI-8 eruption. Terminology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supervolcano World Map
A supervolcano is a volcano that has had an eruption with a Volcanic Explosivity Index (VEI) of 8, the largest recorded value on the index. This means the volume of deposits for such an eruption is greater than 1,000 cubic kilometers (240 cubic miles). Supervolcanoes occur when magma in the mantle rises into the crust but is unable to break through it. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure and ruptures. This can occur at hotspots (for example, Yellowstone Caldera) or at subduction zones (for example, Toba). Large-volume supervolcanic eruptions are also often associated with large igneous provinces, which can cover huge areas with lava and volcanic ash. These can cause long-lasting climate change (such as the triggering of a small ice age) and threaten species with extinction. The Oruanui eruption of New Zealand's Taupō Volcano (about 26,500 years ago) was the world's most recent VEI-8 eruption. Terminology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a Volcanic crater, crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish language, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
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. 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, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellowstone Caldera
The Yellowstone Caldera, sometimes referred to as the Yellowstone Supervolcano, is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States. The caldera and most of the park are located in the northwest corner of Wyoming. The caldera measures , and postcaldera lavas spill out a significant distance beyond the caldera proper. The caldera formed during the last of three supereruptions over the past 2.1 million years: the Huckleberry Ridge eruption 2.1 million years ago (which created the Island Park Caldera and the Huckleberry Ridge Tuff), the Mesa Falls eruption 1.3 million years ago (which created the Henry's Fork Caldera and the Mesa Falls Tuff), and the Lava Creek eruption approximately 640,000 years ago (which created the Yellowstone Caldera and the Lava Creek Tuff). Volcanoes at Yellowstone Volcanism at Yellowstone is relatively recent, with calderas created by large eruptions that took place 2.1 million, 1.3 million, and 640,000 y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oruanui Eruption
The Oruanui eruption of New Zealand's Taupō Volcano (also known as the Kawakawa eruption or Kawakawa/Oruanui event) was the world's most recent Supervolcano#Known supereruptions, supereruption.} Eruption With a Volcanic Explosivity Index of 8, it is one of the largest eruptions ever to occur in New Zealand. It occurred about 26,500 years ago in the Late Pleistocene and generated approximately of pyroclastic fall deposits, of pyroclastic density current (PDC) deposits (mostly ignimbrite) and of primary intracaldera material, equivalent to of magma, totaling of total deposits. The eruption is divided into 10 different phases on the basis of nine geological map, mappable fall strata, units and a tenth, poorly preserved but volumetrically dominant fall unit. Modern-day Lake Taupō, in area and deep, partly fills the caldera generated during this eruption. A structural collapse is concealed beneath Lake Taupō, while the lake outline at least partly reflects volcano-tectonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ejecta
Ejecta (from the Latin: "things thrown out", singular ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials (tephra) that came out of a volcanic explosion and magma eruption volcanic vent, or crater, has traveled through the air or under water, and fell back on the ground surface or on the ocean floor. Volcanology Typically in volcanology, ejecta is a result of explosive eruptions. In an explosive eruption, large amounts of gas are dissolved in extremely viscous lava; this lava froths to the surface until the material is expelled rapidly due to the trapped pressure. Sometimes in such an event a lava plug or volcanic neck forms from lava that solidifies inside a volcano's vent, causing heat and pressure to build up to an extreme with no way to escape. When the blockage breaks and cannot sustain itself any longer, a more violent eruption occurs, which allows materials to be ejected out of the volc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Mazama
Mount Mazama (''Giiwas'' in the Native American language Klamath language, Klamath) is a complex volcano in the state of Oregon, United States, in a segment of the Cascade Volcanoes, Cascade Volcanic Arc and Cascade Range. Most of the mountain collapsed following a major eruption approximately 7,700 years ago. The volcano is in Klamath County, Oregon, Klamath County, in the southern Cascades, north of the Oregon–California border. Its collapse formed a caldera that holds Crater Lake. The mountain is in Crater Lake National Park. Mount Mazama originally had an elevation of , but following its climactic eruption this was reduced to . Crater Lake is deep, the deepest freshwater body in the US and the second deepest in North America after Great Slave Lake in Canada. Mount Mazama formed as a group of overlapping volcanic edifices such as shield volcanoes and small stratovolcano, composite cones, becoming active intermittently until its climactic eruption 7,700 years ago. This e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Toba
Lake Toba ( id, Danau Toba) ( Toba Batak: ᯖᯀᯬ ᯖᯬᯅ; romanized: ''Tao Toba'') is a large natural lake in North Sumatra, Indonesia, occupying the caldera of a supervolcano. The lake is located in the middle of the northern part of the island of Sumatra, with a surface elevation of about , the lake stretches from to . The lake is about long, wide, and up to deep. It is the largest lake in Indonesia and the largest volcanic lake in the world. Toba Caldera is one of twenty Geoparks in Indonesia, and was recognised in July 2020 as one of the UNESCO Global Geoparks. Lake Toba is the site of a supervolcanic eruption estimated at VEI 8 that occurred 69,000 to 77,000 years ago, representing a climate-changing event. Recent advances in dating methods suggest a more accurate identification of 74,000 years ago as the date. It is the largest-known explosive eruption on Earth in the last 25 million years. According to the Toba catastrophe theory, it had global consequences f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Igneous Province
A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive (sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The formation of LIPs is variously attributed to mantle plumes or to processes associated with divergent plate tectonics. The formation of some of the LIPs in the past 500 million years coincide in time with mass extinctions and rapid climatic changes, which has led to numerous hypotheses about causal relationships. LIPs are fundamentally different from any other currently active volcanoes or volcanic systems. Definition In 1992 researchers first used the term ''large igneous province'' to describe very large accumulations—areas greater than 100,000 square kilometers (approximately the area of Iceland)—of mafic igneous rocks that were erupted or emplaced at depth within an extremely short geological time interval: a few million years or less. Maf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taupō Volcano
Lake Taupō, in the centre of New Zealand's North Island, is the caldera of the Taupō Volcano, a large rhyolitic supervolcano. This huge volcano has produced two of the world's most violent eruptions in geologically recent times. ImageSize = width:320 height:800 PlotArea = right:50 top:10 left:50 bottom:10 DateFormat = yyyy TimeAxis = orientation:vertical order:reverse Period = from:-10000 till:2050 AlignBars = early ScaleMajor = unit:year increment:1000 start:-10000 Colors = id:canvas value:rgb(1,1,0.85) BackgroundColors = canvas:canvas PlotData = width:15 color:white bar:test from:-10000 till:1200 # Pre Maori PlotData = width:15 color:yellow bar:test from:1200 till:1840 # Pre accurate PlotData = width:15 color:orange bar:test from:1840 till:2050 # Accurate PlotData = at:-9999 shift:(30,0) text: Recent eruptions of Taupō caldera at:-9999 shift:(200,0) textcolor:red text: Eruptive at:-9850 shift:(80,-1) textcolor:red fontsize:S text:(Er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Eruption
Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three different types of eruptions: * Magmatic eruptions are the most well-observed type of eruption. They involve the decompression of gas within magma that propels it forward. * Phreatic eruptions are driven by the superheating of steam due to the close proximity of magma. This type exhibits no magmatic release, instead causing the granulation of existing rock. * Phreatomagmatic eruptions are driven by the direct interaction of magma and water, as opposed to phreatic erup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizon (BBC TV Series)
''Horizon'' is an ongoing and long-running British documentary television series on BBC Two that covers science and philosophy. History The programme was first broadcast on 2 May 1964 with "The World of Buckminster Fuller" which explored the theories and structures of inventor Richard Buckminster Fuller and included the ''Horizon'' mission statement: "The aim of ''Horizon'' is to provide a platform from which some of the world's greatest scientists and philosophers can communicate their curiosity, observations and reflections, and infuse into our common knowledge their changing views of the universe". ''Horizon'' continues to be broadcast on BBC Two, and in 2009 added a series of films based on the rich ''Horizon'' archive called ''Horizon Guides'' on BBC Four. In December 2016, it was announced that ''Horizon'' will no longer be made exclusively by the BBC's in-house production division, BBC Studios, and the BBC invited independent production companies to pitch to make episodes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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