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Mentolat
Mentolat is an ice-filled, wide caldera in the central portion of Magdalena Island, Aisén Province, Chilean Patagonia. This caldera sits on top of a stratovolcano which has generated lava flows and pyroclastic flows. The caldera is filled with a glacier. Little is known of the eruptive history of Mentolat, but it is thought to be young, with a possible eruption in the early 18th century that may have formed lava flows on the western slope. The earliest activity occurred during the Pleistocene, and Mentolat has had some major explosive eruptions during the Holocene. Etymology and alternative spellings The etymology of Mentolat has been tentatively linked to ''Men (o) lat'', which in the Chono language means "to decipher". Mentolat was referred to as ''Montalat'' on a map of the early 20th century, and other spellings such as ''Menlolat'', ''Montalat'', ''Montolot'' and ''Matalot'' have been identified. Geomorphology and geography Mentolat lies on the central part o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magdalena Island, Aysén Region
Magdalena Island is an island in Aysén Region of southern Chile. The island is located between the Moraleda Channel and the Puyuhuapi Channel, and belongs partially to the Isla Magdalena National Park. The United States Hydrographic Office assigns four different names for this island: ''Isla de Cay'', ''Isla Desierto'', ''Isla Magdalena'', and ''Isla de Motalat''. This large island extends into the continental coast, from which it is divided by the channels just mentioned. In its central part the extinct volcano Montalat rises to a height of 5,446 feet. The crater is at all times full of snow. In. the west coast of the island is Pangal Inlet, which is of no use to navigation. Five miles farther north of this is Senec Island, low and sloping, forming a good day mark, which should be left to the eastward in passing. The fishing community and hamlet of Puerto Gaviota is located in the southwestern part of the island at the meeting point of Puyuhuapi Channel with Moraleda Channel. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra Prominent Peak
An ultra-prominent peak, or Ultra for short, is a mountain summit with a topographic prominence of or more; it is also called a P1500. The prominence of a peak is the minimum height of climb to the summit on any route from a higher peak, or from sea level if there is no higher peak. There are approximately 1,524 such peaks on Earth. Some well-known peaks, such as the Matterhorn and Eiger, are not Ultras because they are connected to higher mountains by high cols and therefore do not achieve enough topographic prominence. The term "Ultra" originated with earth scientist Steve Fry, from his studies of the prominence of peaks in Washington (state), Washington in the 1980s. His original term was "ultra major mountain", referring to peaks with at least of prominence. Distribution Currently, 1,518 Ultras have been identified above sea level: 639 in Asia, 356 in North America, 209 in South America, 120 in Europe (including 12 in the Caucasus), 84 in Africa, 69 in Oceania, and 41 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basaltic Andesite
Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central America and the Andes of South America. Description Basaltic andesite is a fine-grained (aphanitic) igneous rock that is moderately low in silica and low in alkali metal oxides. It is not separately defined in the QAPF classification, which is based on the relative percentages of quartz, alkali feldspar, plagioclase feldspar, and feldspathoids, but would fall in the basalt-andesite field. This corresponds to rock in which feldspathoid makes up less than 10% and quartz less than 20% of the total QAPF fraction, and in which at least 65% of the feldspar is plagioclase. Basaltic andesite would be further distinguished from basalt and andesite by a silica content between 52% and 57%. Although classification by mineral content is preferred by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Dome
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 structures on the Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Flow
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] |
Cerro Hudson
Mount Hudson ( es, Volcán Hudson, es, Monte Hudson, label=none) is a stratovolcano in southern Chile, and the site of one of the largest eruptions in the twentieth century. The mountain itself is covered by a glacier. There is a caldera at the summit from an ancient eruption; modern volcanic activity comes from inside the caldera. Mount Hudson is named after Francisco Hudson, a 19th-century Chilean Navy hydrographer. Eruptive history The first large explosive eruption of the volcano dates, the "H0" eruption, to around 15,450 BCE. Subsequent large eruptions around 4750 BCE and 1890 BCE are believed to have been of Volcanic explosivity index (VEI) 6; these are probably responsible for the large caldera. The 4750 BCE eruption, also known as "H1", may have wiped out many or all of the groups living in central Patagonia at that time, based on evidence from the Los Toldos archaeological site, and the sudden ceasing of rock art production in the area around that time, includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerro Azul (Chile Volcano)
Cerro Azul (, ''blue hill'' in Spanish), sometimes referred to as Quizapu, is an active stratovolcano in the Maule Region of central Chile, immediately south of Descabezado Grande. Part of the South Volcanic Zone of the Andes, its summit is above sea level, and is capped by a summit crater that is wide and opens to the north. Beneath the summit, the volcano features numerous scoria cones and flank vents. Cerro Azul is responsible for several of South America's largest recorded eruptions, in 1846 and 1932. In 1846, an effusive eruption formed the vent at the site of present-day Quizapu crater on the northern flank of Cerro Azul and sent lava flowing down the sides of the volcano, creating a lava field 8–9 square kilometres (3–3.5 square miles) in area. Phreatic and Strombolian volcanism between 1907 and 1932 excavated this crater. In 1932, one of the largest explosive eruptions of the 20th century occurred at Quizapu Crater and sent of ash into the atmosphere. The vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maipo (volcano)
Maipo is a stratovolcano in the Andes, lying on the border between Argentina and Chile. It is located south of Tupungato and about southeast of Santiago. It has a symmetrical, conical volcanic shape, and is among the southernmost 5,000 metre peaks in the Andes. Maipo is located within the Diamante caldera, a feature measuring 15 km by 20 km that is about half a million years old. It rises about 1,900 m (6,230 ft) above the floor of the caldera. Immediately to the east of the peak, on the eastern side of the caldera floor, is Laguna del Diamante, a lake that formed when lava flows blocked drainage channels from the caldera in 1826. The Diamante Caldera erupted of tephra, 450 ka. The region's climate is transitional between the drier Mediterranean climate of the peaks to the north and the cold, moist climate of Chilean Patagonia. Hence, while less glaciated than Patagonia, it has more permanent snow on the wet, Chilean side than peaks of similar el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today, although a third epoch, the Anthropocene, has been proposed but is not yet officially recognised by the ICS). The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders" ( it, quattro ordini). The term "quaternary" was introduced by Jules Desnoye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Arc
A volcanic arc (also known as a magmatic arc) is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc located further from the subducting plate than the trench. The oceanic plate is saturated with water, mostly in the form of hydrous minerals such as micas, amphiboles, and serpentine minerals. As the oceanic plate is subducted, it is subjected to increasing pressure and temperature with increasing depth. The heat and pressure break down the hydrous minerals in the plate, releasing water into the overlying mantle. Volatiles such as water drastically lower the melting point of the mantle, causing some of the mantle to melt and form magma at depth under the overriding plate. The magma ascends to form an arc of volcanoes parallel to the subduction zone. Volcanic arcs are distinct from volcanic chains formed over hotspots in the middle of a te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puyuhuapi
Puyuhuapi (Puyuguapi) is a village in southern Chile in the Aysén Region. It is located on Route 7, the Carretera Austral, where the Rio Pascal enters the head of the Puyuhuapi fjord, a small fjord off the Ventisquero Sound. Its harbor on the fjord is called Puerto Puyuhuapi. Puyuhuapi is administratively in the Chilean commune of Cisnes. In the 2002 census it had a population of 535, but by 2007 it had grown to 826. Just southwest of the village are the Puyuhuapi hot springs. The government invited German settlement in the village, which was founded by Sudeten German settlers from Hranice (former German name Rossbach) in present-day Czech Republic and Mapuches from Chiloé Archipelago. German settlers gave temporary work to the Mapuches in the area, and then they settled with their families, which gave rise to a mestizo population. It is served by Puyuhuapi Airport. Among the local handicrafts are hand-made jerseys. In popular culture Puyuhuapi was featured in the 2014 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
