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Volcanoes Of Chile
Volcanism of Chile is a continuous volcanic process that has a strong influence on Chilean landscape, geology, economy and society. Volcanism constantly renews the Chilean landscape with lava flows, lava plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes, and maars. Volcanism in Chile as well as in other parts of the world is also associated with multiple natural hazards such as lahars, earthquakes, pyroclastic flows, toxic gases and ash. Continental Chile has a high concentration of active volcanoes due to its location along the Peru–Chile Trench, a subduction zone where the Nazca and Antarctic Plates are driven beneath the South American Plate. Chile has been subject to volcanism since at least late Paleozoic when subduction along the western margin of South America began. Easter Island, Juan Fernández Islands and other oceanic islands of Chile are extinct volcanoes created by hotspots. The ''Servicio N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaitén
Chaitén (, ) is a Chilean town, commune and former capital of the Palena Province in Los Lagos Region. The town is north of the mouth of Yelcho River, on the east coast of the Gulf of Corcovado. The town is strategically close to the northern end of the Carretera Austral, where the highway goes inland. The Desertores Islands are part of the commune. Evacuation The town was evacuated in May 2008 when the Chaitén volcano erupted for the first time in more than 9,000 years. The eruption, which commenced May 2, became more violent on May 5, throwing up a high plume of ash and sulfurous steam that rose to , from which ashfall drifted across Patagonia and over the Atlantic Ocean. During 2005 small earthquakes occurred below Chaitén and the nearby Liquiñe-Ofqui Fault Zone. The town was completely flooded on May 12, 2008, after a lahar caused the banks of the Blanco River to overflow about on each side. Over the subsequent weeks, the river excavated a new course through Chaitén ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lahar
A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extremely destructive: they can flow tens of metres per second, they have been known to be up to deep, and large flows tend to destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the latter of which killed thousands of people in the town of Armero. Etymology The word ''lahar'' is of Javanese origin. Berend George Escher introduced it as a geological term in 1922. Description The word ''lahar'' is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular rheology or sediment concentration. Lahars can occur as normal stream flows (sediment concentration of less than 30%), hyper-concentrated stream flows (sediment concentration between 30 and 60% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency of Norway), Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South American Plate
The South American Plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African Plate, with which it forms the southern part of the Mid-Atlantic Ridge. The easterly edge is a divergent boundary with the African Plate; the southerly edge is a complex boundary with the Antarctic Plate, the Scotia Plate, and the Sandwich Plate; the westerly edge is a convergent boundary with the subducting Nazca Plate; and the northerly edge is a boundary with the Caribbean Plate and the oceanic crust of the North American Plate. At the Chile Triple Junction, near the west coast of the Taitao–Tres Montes Peninsula, an oceanic ridge known as the Chile Rise is actively subducting under the South American Plate. Geological research suggests that the South American Plate is moving westward away from the Mid-Atlantic Ridge: "Parts of the plate boundaries consisting of alternations of relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Plate
The Antarctic Plate is a tectonic plate containing the continent of Antarctica, the Kerguelen Plateau, and some remote islands in the Southern Ocean and other surrounding oceans. After breakup from Gondwana (the southern part of the supercontinent Pangea), the Antarctic plate began moving the continent of Antarctica south to its present isolated location, causing the continent to develop a much colder climate. The Antarctic Plate is bounded almost entirely by extensional mid-ocean ridge systems. The adjoining plates are the Nazca Plate, the South American Plate, the African Plate, the Somali Plate, the Indo-Australian Plate, the Pacific Plate, and, across a transform boundary, the Scotia Plate. The Antarctic Plate has an area of about . It is Earth's fifth-largest tectonic plate. The Antarctic Plate's movement is estimated to be at least per year towards the Atlantic Ocean. Subduction beneath South America The Antarctic Plate started to subduct beneath South America 14 mil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nazca Plate
The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the Nazca Plate under the South American Plate is largely responsible for the Andean orogeny. The Nazca Plate is bounded on the west by the Pacific Plate and to the south by the Antarctic Plate through the East Pacific Rise and the Chile Rise respectively. The movement of the Nazca Plate over several hotspots has created some volcanic islands as well as east-west running seamount chains that subduct under South America. Nazca is a relatively young plate both in terms of the age of its rocks and its existence as an independent plate having been formed from the break-up of the Farallon Plate about 23 million years ago. The oldest rocks of the plate are about 50 million years old. Boundaries East Pacific and Chile Rise A triple junctio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peru–Chile Trench
The Peru–Chile Trench, also known as the Atacama Trench, is an oceanic trench in the eastern Pacific Ocean, about off the coast of Peru and Chile. It reaches a maximum depth of below sea level in Richards Deep () and is approximately long; its mean width is and it covers an expanse of some . The trench delineates the boundary between the subducting Nazca Plate and the overriding South American Plate. Geology The trench is a result of a convergent plate boundary, where the eastern edge of the oceanic Nazca Plate is being subducted beneath the continental South American Plate. The trench is also a part of the Chile Triple Junction, an unusual junction that consists of a mid-oceanic ridge and the Chile Rise being subducted under the South American plate at the Peru-Chile Trench. Two seamount ridges within the Nazca Plate enter the subduction zone along this trench: the Nazca Ridge and the Juan Fernández Ridge. From the Chile Triple Junction to Juan Fernández Ri ... [...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] |
Continental Chile
Continental Chile is the name given to the Chilean territory located on the continental shelf of South America. This term serves to distinguish the South American area from the insular territories, known as Insular Chile, as from the Antarctic Chile (Chilean Antarctic Territory). The existence of this three areas of effective or claimed Chilean sovereignty is what supports the existing tricontinental principle in this country. In addition, this term specifies the time zones of mainland Chile and the Juan Fernández Islands and the Desventuradas Islands, located in the UTC−4 time zone, as "continental Chile" however, the Magallanes and Chilean Antarctica Region are in the UTC–3 time zone. Easter Island and the Isla Salas y Gómez, both in Polynesia, are in the UTC−6 time zone. Continental Chile has a surface of 756,770 km2, representing 99.976% of the total surface of the country under effective administration. However, considering the claim in Antarctic, this perce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as ''tephra''), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away. Due to its wide dispersal, ash can have a number of impacts on society, including animal a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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