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Effusive Eruption
An effusive eruption is a type of volcanic eruption in which lava steadily flows out of a volcano onto the ground. Overview There are two major groupings of eruptions: effusive and explosive. Effusive eruption differs from explosive eruption, wherein magma is violently fragmented and rapidly expelled from a volcano. Effusive eruptions are most common in basaltic magmas, but they also occur in intermediate and felsic magmas. These eruptions form lava flows and lava domes, each of which vary in shape, length, and width. Deep in the crust, gasses are dissolved into the magma because of high pressures, but upon ascent and eruption, pressure drops rapidly, and these gasses begin to exsolve out of the melt. A volcanic eruption is effusive when the erupting magma is volatile poor (water, carbon dioxide, sulfur dioxide, hydrogen chloride, and hydrogen fluoride), which suppresses fragmentation, creating an oozing magma which spills out of the volcanic vent and out into the surroundin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Types Of Volcanic Eruptions
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] |
Aa Channel Flow From Mauna Loa
AA, Aa, Double A, or Double-A may refer to: Arts, entertainment and media * ''America's Army'', a 2002 computer game published by the U.S. Army * '' Ancient Anguish'', a computer game in existence since 1992 * Aa!, a J-Pop musical group * Double-A (band), stylised as AA, South Korean boy band * ''Aa'' (album), a 2016 album by Baauer * AA (song), a 2021 single by Walker Hayes * Ace Attorney, a series of video games developed by Capcom. *AA Films, an Indian film distribution company * AA Book (other) *AA, the production code for the 1966 ''Doctor Who'' serial '' The Savages'' Brands, organizations and enterprises * Alcoholics Anonymous, an international fellowship dedicated to helping alcoholics peer to peer in sobriety * A. A. Arms, a defunct firearms manufacturer * Aerolíneas Argentinas, an Argentine airline (logo used to consist of two A's) * Air Asia, an Asian multinational low cost carrier * Alcoa, an American aluminum-producing company (stock symbol AA) * Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Domes
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on Earth are lava dome forming. The geochemistry of lava domes can vary from basalt (e.g. Semeru, 1946) to rhyolite (e.g. Chaiten, 2010) although the majority are of intermediate composition (such as Santiaguito, dacite- andesite, present day) The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and easily break apart by further input of fluid lava, most of the preserved domes have high silica content and consist of rhyolite or dacite. Existence of lava domes has been suggested for some domed str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism
Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called a vent. It includes all phenomena resulting from and causing magma within the crust or mantle of the body, to rise through the crust and form volcanic rocks on the surface. Magmas, that reach the surface and solidify, form extrusive landforms. Volcanic processes Magma from the mantle or lower crust rises through the crust towards the surface. If magma reaches the surface, its behavior depends on the viscosity of the molten constituent rock. Viscous (thick) magma produces volcanoes characterised by explosive eruptions, while non-viscous (runny) magma produce volcanoes characterised by effusive eruptions pouring large amounts of lava onto the surface. In some cases, rising magma can cool and solidify without reaching the surface. Inste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Country Rock (geology)
In geology, country rock is the rock native to an area, in contrast to any intrusion of viscous geologic material, commonly magma, or perhaps rock salt (in salt domes) or unconsolidated sediments. Magma is typically less dense than the rock it intrudes, widening and filling existing cracks, sometimes melting the already-existing country rock. The term "country rock" is similar to, and in many cases interchangeable with, the terms basement (geology), basement and wall rocks. Country rock can denote the widespread lithology of a region in relation to the rock which is being discussed or observed. Geologic settings Settings in geology when the term ''country rock'' is used include: Igneous intrusions When describing a intrusion, pluton or dike (geology), dike, the igneous rock can be described as intruding the surrounding ''country rock'', the rock into which the pluton has intruded.Newfoundland and LabradorGlossary of Geological Terms Accessed June 2018. When coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected area a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shield Volcano
A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava erupted from a stratovolcano. Repeated eruptions result in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form. Shield volcanoes are found wherever fluid low-silica lava reaches the surface of a rocky planet. However, they are most characteristic of ocean island volcanism associated with hot spots or with continental rift volcanism. They include the largest volcanoes on earth, such as Tamu Massif and Mauna Loa. Giant shield volcanoes are found on other planets of the Solar System, including Olympus Mons on Mars and Sapas Mons on Venus. Etymology The term 'shield volcano' is taken from the German term ''Schildvulkan'', coined by the Austrian geologist Eduard Suess in 1888 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Diego State University
San Diego State University (SDSU) is a public research university in San Diego, California. Founded in 1897 as San Diego Normal School, it is the third-oldest university and southernmost in the 23-member California State University (CSU) system. In Fall 2022, SDSU hit an all time high enrollment record student body of nearly 37,000 and an alumni base of more than 300,000. It is classified among "R2: Doctoral Universities – High research activity". In the 2015–16 fiscal year, the university obtained $130 million in public and private funding—a total of 707 awards—up from $120.6 million the previous fiscal year. As reported by the Faculty Scholarly Productivity Index released by the Academic Analytics organization of Stony Brook, New York, SDSU had the highest research output of any small research university in the United States in 2006 and 2007. SDSU sponsors the second-highest number of Fulbright Scholars in the State of California, just behind UC Berkeley. Since 2005, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pāhoehoe
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ʻaʻā
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of Venus, which cover ~80% of the surface, are basaltic; the lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flows that can spread over great areas before cooling and solidifying. Flood basalts are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of Venus, which cover ~80% of the surface, are basaltic; the lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flows that can spread over great areas before cooling and solidifying. Flood basalts are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
