A windows (pop-into) of information (full-content of Sensagent) triggered by double-clicking any word on your webpage. Volcanic plume may refer to: Eruption column, or volcanic plume, a column of hot volcanic ash and gas emitted into the atmosphere during an explosive volcanic eruption. The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. In the late 1980s and early 1990s, experiments with thermal models showed that as the bulbous head expands it may entrain some of the adjacent mantle into the head. Pillow lava: a smooth, rounded type of lava flow that erupts underwater. A volcano is an opening in Earth ’s crust. the mantle plume, driven by heat exchange across the core-mantle boundary carrying heat upward in a narrow, rising column, and postulated to be independent of plate motions. Very little is produced, and little has been added to the Earth by other processes since then. [7] Thermal or compositional fluid-dynamical plumes produced in that way were presented as models for the much larger postulated mantle plumes. Most material © 2005, 1997, 1991 by Penguin Random House LLC. Another word for plume. They tend to be pitted and full of holes, which gives them a low density.Along with water vapor and other hot gases, volcanic ash is part of the dark ash column that rises above a volcano when it erupts. If your word has any anagrams, they'll be listed too along with a definition for the word if we have one. The mantle plume hypothesis predicts that domal topographic uplifts will develop when plume heads impinge on the base of the lithosphere. a plume of smoke; A radioactive plume could reach the city within hours. osmium, have been suggested to be tracers of material arising from near to the Earth's core, in basalts at oceanic islands. The volcano could spew ash again with little warning. The most remarkable example of this is the Emperor chain, the older part of the Hawaii system, which was formed by migration of volcanic activity across a geo-stationary plate.[13]. It is thus not clear how strongly this observation supports the mantle plume hypothesis. By using our services, you agree to our use of cookies. Volcanic activity at Banaga is frequent but non-explosive, usually producing lava that fills a lake at the volcano’s summit. Give contextual explanation and translation from your sites ! ○ Boggle. Définitions de volcanique. Here are key things to know about the latest volcanic threat: WHAT IS LAVA HAZE? The chemical and isotopic composition of basalts found at hotspots differs subtly from mid-ocean-ridge basalts. On July 12, 2008, Okmok Volcano, in Alaska’s Aleutian Islands erupted, releasing a plume of ash and steam. Explosive activity continues. Modified entries © 2019 by Penguin Random House LLC and HarperCollins Publishers Ltd. Active volcano: a volcano that has erupted in the past 10,000 years, may be currently erupting, ... Mantle plume: a column of hot rock that rises up to the surface from Earth’s interior. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. [13], The eruption of continental flood basalts is often associated with continental rifting and breakup. Volcanic plume may refer to: Eruption column, or volcanic plume, a column of hot volcanic ash and gas emitted into the atmosphere during an explosive volcanic eruption. Du gibier à plume, sans s. remarque Plume signifie ici « plumage » comme poil signifie « pelage » dans gibier à poil. 1) What is a hotspot?A volcanic "hotspot" is an area in the upper mantle from which heat rises in a plume from deep in the Earth. Some common and basic lines of evidence cited in support of the theory are linear volcanic chains, noble gases, geophysical anomalies, and geochemistry. The interdisciplinary Plume-Lithosphere Undersea Mantle Experiment studies the shape and the origin of the mantle plume beneath the Hawaiian hotspot that is responsible for spectacular volcanism on the surface.The centerpiece of this 5-year project is an unprecedented long-term deployment of broad-band OBS (ocean bottom seismometers) to record teleseismic earthquakes. [4] In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, would provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain. In the context of the alternative "Plate model", continental breakup is a process integral to plate tectonics, and massive volcanism occurs as a natural consequence when it starts. a vertically or longitudinally moving, rising, or expanding fluid body, as of smoke or water. Qui est plein de fougue, de violence, d'ardeur : Une passion volcanique. Active volcano: a volcano that has erupted in the past 10,000 years, may be currently erupting, ... Mantle plume: a column of hot rock that rises up to the surface from Earth’s interior. Another hypothesis for unusual volcanic regions is the "Plate model". Eco, Cookies help us deliver our services. The bulbous head of thermal plumes forms because hot material moves upward through the conduit faster than the plume itself rises through its surroundings. These plumes are thought to be stationary relative to the lithospheric plates that move over them. Helium-3 is a primordial isotope that formed in the Big Bang. It is made of dense white clouds of steam, toxic gas and tiny shards of volcanic glass. [26][27], Various lines of evidence have been cited in support of mantle plumes. [2]:277, Under the umbrella of the plate hypothesis, the following sub-processes, all of which can contribute to permitting surface volcanism, are recognised:[2]. In the context of the Plate hypothesis, subducted material is mostly re-circulated in the shallow mantle and tapped from there by volcanoes. Seismic waves that have traveled a thousand or more kilometers (also called teleseismic waves) can be used to image large regions of Earth's mantle. [2], Mantle plumes were first proposed by J. Tuzo Wilson in 1963[3][non-primary source needed] and further developed by W. Jason Morgan in 1971. Another word for plume. An intrinsic aspect of the plume hypothesis is that the "hot spots" and their volcanic trails have been fixed relative to one another throughout geological time. "Ocean island basalt" is also similar to basalts found throughout the oceans on both small and large seamounts (thought to be formed by eruptions on the sea floor that did not rise above the surface of the ocean). These plumes are thought to be stationary relative to the lithospheric plates that move over them. As a result, scientific interaction is often hampered because individuals use the word “plume” to mean different physical models without each other realising. n. a plume of smoke une colonne de fumée. Beginning in the early 2000s, dissatisfaction with the state of the evidence for mantle plumes and the proliferation of ad hoc hypotheses drove a number of geologists, led by Don L. Anderson, Gillian Foulger, and Warren B. Hamilton, to propose a broad alternative based on shallow processes in the upper mantle and above, with an emphasis on plate tectonics as the driving force of magmatism.[45]. The English word games are: In addition to these processes, impact events such as ones that created the Addams crater on Venus and the Sudbury Igneous Complex in Canada are known to have caused melting and volcanism. [14], The current mantle plume theory is that material and energy from Earth's interior are exchanged with the surface crust in two distinct modes: the predominant, steady state plate tectonic regime driven by upper mantle convection, and a punctuated, intermittently dominant, mantle overturn regime driven by plume convection. [43], Many continental flood basalt events coincide with continental rifting. Guatemala A dream destination for volcano enthusiasts and photographers! Enhanced volcanism at plate boundary junctions; Abrupt lateral changes in stress at structural discontinuities; Sublithospheric melt ponding and draining. This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension. A mantle plume is a proposed mechanism of convection of abnormally hot rock within the Earth's mantle. Image of the Day Atmosphere Land Volcanoes A … When a plume head encounters the base of the lithosphere, it is expected to flatten out against this barrier and to undergo widespread decompression melting to form large volumes of basalt magma. Jump to: navigation, search. However, it is almost unique on Earth, as nothing as extreme exists anywhere else. The narrow vertical pipe, or conduit, postulated to connect the plume head to the core-mantle boundary, is viewed as providing a continuous supply of magma to a fixed location, often referred to as a "hotspot". There are two competing interpretations for this. Se dit d'un relief, d'une roche, d'un gaz ou d'un phénomène lié à la dynamique des volcans. Letters must be adjacent and longer words score better. See if you can get into the grid Hall of Fame ! Term: Basalt. This is consistent with a system that tends toward equilibrium: as matter rises in a mantle plume, other material is drawn down into the mantle, causing rifting.[44]. Volcanic Ash Advisory Center (VAAC) Darwin warned about a volcanic ash plume that rose up to estimated 16000 ft (4900 m) altitude or flight level 160 . In the plate hypothesis, the slabs are postulated to have been recycled at shallower depths – in the upper few hundred kilometers that make up the upper mantle. [4] This second regime, while often discontinuous, is periodically significant in mountain building[15] and continental breakup.[16]. Glossary Terms. Regards, The Crossword Solver Team. Glossary Terms. C. Caldera CE Cinder cone Cirque Composite volcano Coulee Crust Cryptodome Cumulo-volcano. The volcanic plume is faint in this true-color image, and the volcano’s summit is obscured by clouds, but the plume clearly blows away from Bougainville and over the Pacific Ocean. The Moderate Resolution Imaging Spectroradiometer on NASA’s Aqua satellite took this picture on August 9, 2009. Two very broad, large low-shear-velocity provinces, exist in the lower mantle under Africa and under the central Pacific.
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