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Lonquimay (volcano)
Lonquimay Volcano is a stratovolcano of late-Pleistocene to dominantly Holocene age, with the shape of a truncated cone. The cone is largely andesitic, though basaltic and dacitic rocks are present. It is located in the La Araucanía Region of Chile, immediately SE of Tolhuaca volcano. Sierra Nevada and Llaima are their neighbors to the south. The snow-capped volcano lies within the protected area Malalcahuello-Nalcas. The volcano's last eruption began on December 25, 1988, earning it the nickname "Navidad". The eruption lasted for 13 months before ending in 1990. The Volcanic Explositivy Index was 3, indicating tropospheric injections and catastrophic damage. The eruption was from a flank vent and involved mostly andesite lava, and had been preceded by increased seismicity for three weeks. The volume of the lava flow decreased as time went on and the vent dimensions decreased, though by the end of the eruption the andesite had still built up to a length of 10.2 km. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Pacific Ocean. Chile had a population of 17.5 million as of the latest census in 2017 and has a territorial area of , sharing borders with Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage to the south. The country also controls several Pacific islands, including Juan Fernández Islands, Juan Fernández, Isla Salas y Gómez, Desventuradas Islands, Desventuradas, and Easter Island, and claims about of Antarctica as the Chilean Antarctic Territory. The capital and largest city of Chile is Santiago, and the national language is Spanish language, Spanish. Conquest of Chile, Spain conquered and colonized the region in the mid-16th century, replacing Incas in Central Chile, Inca rule; however, they Arauco War ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Explosivity Index
The volcanic explosivity index (VEI) is a scale used to measure the size of explosive volcanic eruptions. It was devised by Christopher G. Newhall of the United States Geological Survey and Stephen Self in 1982. Volume of products, eruption cloud height, and qualitative observations (using terms ranging from "gentle" to "mega-colossal") are used to determine the explosivity value. The scale is open-ended with the largest eruptions in history given a magnitude of 8. A value of 0 is given for non-explosive eruptions, defined as less than of tephra ejected; and 8 representing a supervolcanic eruption that can eject (240 cubic miles) of tephra and have a cloud column height of over . The scale is logarithmic, with each interval on the scale representing a tenfold increase in observed ejecta criteria, with the exception of between VEI-0, VEI-1 and VEI-2. Classification With indices running from 0 to 8, the VEI associated with an eruption is dependent on how much volcanic materia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene Stratovolcanoes
The Pleistocene ( ; referred to colloquially as the ''Ice Age'') is the geological epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold glacial periods and warmer interglacials, with the sea levels being up to lower th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Volcanoes
An active volcano is a volcano that is currently erupting, or has the potential to erupt in the future. Conventionally it is applied to any that have erupted during the Holocene (the current geologic epoch that began approximately 11,700 years ago). A volcano that is not currently erupting but could erupt in the future is known as a dormant volcano. Volcanoes that will not erupt again are known as extinct volcanoes. Overview There are 1,350 potentially active volcanoes around the world, 500 of which have erupted in historical time. Many active volcanoes are located along the Pacific Rim, also known as the Pacific Ring of Fire. An estimated 500 million people live near active volcanoes. ''Historical time'' (or recorded history) is another timeframe for ''active''. The span of recorded history differs from region to region. In China and the Mediterranean, it reaches back nearly 3,000 years, but in the Pacific Northwest of the United States and Canada, it reaches back less tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratovolcanoes Of Chile
A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and explosive eruptions. Some have collapsed summit craters called calderas. The lava flowing from stratovolcanoes typically cools and solidifies before spreading far, due to high viscosity. The magma forming this lava is often felsic, having high to intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less viscous mafic magma. Extensive felsic lava flows are uncommon, but can travel as far as 8 km (5 mi). The term ''composite volcano'' is used because strata are usually mixed and uneven instead of neat layers. They are among the most common types of volcanoes; more than 700 stratovolcanoes have erupted lava during the Holocene Epoch (the last 11,700 years), and many older, now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountains Of Chile
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Araucanía Region
A volcano is commonly defined as a vent or fissure in the Crust (geology), crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where list of tectonic plates, tectonic plates are divergent boundary, diverging or convergent boundary, converging, and because most of Earth's plate boundaries are underwater, most volcanoes 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 resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism Of Chile
Volcanism of Chile is a continuous volcanic process that has a strong influence on Chilean geography of Chile, landscape, geology of Chile, geology, economy of Chile, economy and society. Volcanism constantly renews the Chilean landscape with lava flows, volcanic plateau, 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 volcanic ash, ash. Continental Chile has a high concentration of active volcanoes due to its location along the Peru–Chile Trench, a subduction, subduction zone where the Nazca Plate, 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 Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanoes In Chile
The Smithsonian Institution's Global Volcanism Program lists 105 volcanoes in Chile that have been active during the Holocene. using Chile, Chile-Peru, Chile-Bolivia and Chile-Argentina options, retrieved on 10 November 2013 The country's National Geology and Mining Service lists 90 active volcanoes. The volcanoes of the originate from the of the |
Parasitic Cone
A parasitic cone (also adventive cone, satellite cone, satellitic cone or lateral cone) is the cone-shaped accumulation of volcanic material not part of the central vent of a volcano. It forms from eruptions from fractures on the flank of the volcano. These fractures occur because the flank of the volcano is unstable. Eventually, the fractures reach the magma chamber and generate eruptions called flank eruptions, which, in turn, produce a parasitic cone. A parasitic cone can also be formed from a dike or sill cutting up to the surface from the central magma chamber in an area different from the central vent. A peculiar example of multiple parasitic cones is Jeju Island in South Korea. Jeju Island features 368 " oreums" (Korean: ; "mount"), which lie in a roughly lateral line on either side of the island's central dormant shield volcano Hallasan. See also * Volcanic crater A volcanic crater is an approximately circular depression in the ground caused by volcanic activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fracture in the Crust (geology), crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is often also 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. Etymology The word ''lava'' comes from Ital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troposphere
The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the planetary surface of the Earth, the average height of the troposphere is in the tropics; in the middle latitudes; and in the high latitudes of the polar regions in winter; thus the average height of the troposphere is . The term ''troposphere'' derives from the Greek words ''tropos'' (rotating) and ''sphere, sphaira'' (sphere) indicating that rotational turbulence mixes the layers of air and so determines the structure and the phenomena of the troposphere. The rotational friction of the troposphere against the planetary surface affects the flow of the air, and so forms the planetary boundary layer (PBL) that varies in height from hundreds of meters up to . The measures of the PBL vary according to the latitude, the landform, and the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
