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Hornito
Hornitos are conical, or pipe-like, structures built up by lava spattering or being ejected through an opening in the crust of a lava flow. Hornitos are similar to Volcanic cone#Spatter cone, spatter cones but are rootless, meaning they were once a source of lava but that source was not directly associated with a true vent or magma source. They are usually created by the slow upwelling of fluid lava through the roof of a lava tube, and are often associated with pahoehoe lavas of basaltic composition. High pressure causes lava to ooze and spatter out. The lava builds up on the surface and solidifies creating the initial structure. Hornitos can grow and exceed 10 meters in height. Some classic examples of hornitos have been described, or depicted, from volcanoes including El Jorullo, Mexico which was visited by Alexander von Humboldt in 1803; Kilauea Hawaii; and Oldoinyo Lengai, Tanzania. The term hornito comes from the Spanish, meaning 'little oven'; a reference to the way t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Tube
A lava tube, more rarely called a pyroduct, is a 'roofed conduit through which molten lava travels away from its vent'. If lava in the tube drains out, it will leave an empty cave. Lava tubes are common in low-viscosity volcanic systems. Lava tubes are important as they are able to transport molten lava much further away from the eruptive vent than lava channels. A tube-forming lava flow can emplace on longer distance due to the presence of a solid crust protecting the molten lava from atmospheric cooling. Lava tubes are often considered when preparing hazard maps or managing an eruptive crisis. Formation A lava tube is a type of lava cave formed when a low-viscosity lava flow develops a continuous and hard crust, which thickens and forms a roof above the still-flowing lava stream. Three main formation mechanisms have been described: (1) roofing over a lava channel, (2) pāhoehoe lobe extension or (3) lava flow inflation. # When it erupts from a vent, lava usually flow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Cone
Volcanic cones are among the simplest volcanic landforms. They are built by ejecta from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and size of the fragments ejected during the eruption. Types of volcanic cones include stratocones, spatter cones, tuff cones, and cinder cones. Stratocone Stratocones are large cone-shaped volcanoes made up of lava flows, explosively erupted pyroclastic rocks, and igneous intrusives that are typically centered around a cylindrical vent. Unlike shield volcanoes, they are characterized by a steep profile and periodic, often alternating, explosive eruptions and effusive eruptions. Some have collapsed craters called calderas. The central core of a stratocone is commonly dominated by a central core of intrusive rocks that range from around to over several kilometers in diameter. This central core is surrounded by multiple generations of lav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oldoinyo Lengai
Ol Doinyo Lengai is an active volcano in northern Tanzania. It consists of a volcanic cone with two craters, the northern of which has erupted during historical time. Uniquely for volcanoes on Earth, it has erupted natrocarbonatite, an unusually low temperature and highly fluid type of magma. Eruptions in 2007–2008 affected the surrounding region. Name The Maasai and Sonjo people refer to the volcano as "The Mountain of God", associated with a myth of the abode of the god Engai, who withdrew there after being hit by a hunter with an arrow. Other names are Basanjo, Donjo Ngai, Duenjo Ngai, Mongogogura, Mungogo wa Bogwe, and Oldonyo L'Engai. Geography and geomorphology Ol Doinyo Lengai lies in the Arusha region of Tanzania, south of Lake Natron and northwest of the city of Arusha. The summit was first explored between 1904 and 1915. , about 300,000 people live in the region, and livestock farming is the most important economic activity, although tourism is increasingly import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chapelle Rosemont2
Chapelle or La Chapelle may refer to: Communes in France * La Chapelle, Allier * La Chapelle, Ardennes * La Chapelle, Charente * La Chapelle, Savoie * Les Chapelles, Savoie department * La Chapelle (Seine), a former commune of Paris Other places * Église de la Chapelle or Kapellekerk, a church in Brussels * Quartier de La Chapelle, a neighborhood of Paris, France * La Chapelle (Paris Metro), a metro station in Paris, France * Porte de la Chapelle (Paris Metro), a metro station in Paris, France * Sainte-Chapelle, a Gothic chapel on the Île de la Cité, Paris, France * La Chapelle, Artibonite, a commune in Artibonite department, Haiti * La Chapelle, a commune of Plan-les-Ouates, Switzerland * Chapelle, Glâne, a former municipality of the canton of Fribourg, Switzerland * Archbishop Chapelle High School, a high school in New Orleans, United States * Aix-la-Chapelle or Aachen, Germany Other uses * La Chapelle (Church), a Baptist Evangelical multi-site church based in Montrea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauna Ulu Hornito
Mauna or Mouna may refer to: * ''Mauna'' (moth), genus of moths in the family Geometridae * Mauna (silence), silence in Hindu philosophy ** Maun Vrata, term for a vow of silence in India * Mauna, Käbschütztal, village in Käbschütztal, Germany * A Hawaiian word for mountain, used in the following Hawaiian volcano names: ** Mauna Loa, on Hawai'i ** Mauna Kea, on Hawai'i ** Mauna Ulu, cinder cone of Kīlauea, on Hawai'i ** Mauna Iki, cinder cone of Kīlauea, on Hawai'i ** Mauna Haleakalā, on Maui ** Mauna Hina, cinder cone of Haleakalā See also *Maun (other) Maun may refer to: Places * Maun, Botswana, a town in the North-West District * River Maun, a river in England * Maun (island), an island in the Adriatic Sea People * Caroline Maun (born 1968), American professor, author, poet, lyricist and mus ... * Mouna Ragam (other) {{disambig ... [...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] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and volcanic gas, gas bubbles. Magma is produced by melting of the mantle (geology), mantle or the Crust (geology), crust in various tectonics, tectonic settings, which on Earth include subduction zones, continental rift (geology), rift zones, mid-ocean ridges and Hotspot (geology), hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal mush, crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by Fractional crystallization (geology), fractional crystallization, contaminati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pahoehoe
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 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 Italian and is probably derived from the Latin word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basaltic
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 thick s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Jorullo
El Jorullo is a cinder cone volcano in Michoacán, central Mexico, on the southwest slope of the central plateau, southeast of Uruapan in an area known as the Michoacán-Guanajuato volcanic field. It is about east-northeast of La Huacana. Its current elevation is . El Jorullo has four smaller cinder cones which have grown from its flanks. The vents of El Jorullo are aligned in a northeast to southwest direction. Lava from these vents cover nine square km around the volcano. Later eruptions produced lavas that had higher silica contents making them thicker than the earlier basalts and basaltic andesite lavas. El Jorullo's crater is about 1,300 by 1,640 feet (400 by 500 m) wide and deep. El Jorullo is one of two known volcanoes to have developed in Mexico in recent history. The second, born about 183 years later, was named Parícutin after a nearby village that it eventually destroyed. Parícutin is about northwest of El Jorullo. El Jorullo was first erupted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Von Humboldt
Friedrich Wilhelm Heinrich Alexander von Humboldt (14 September 1769 – 6 May 1859) was a German polymath, geographer, natural history, naturalist, List of explorers, explorer, and proponent of Romanticism, Romantic philosophy and Romanticism in science, science. He was the younger brother of the Prussian minister, philosopher, and linguistics, linguist Wilhelm von Humboldt (1767–1835). Humboldt's quantitative work on botany, botanical geography laid the foundation for the field of biogeography, while his advocacy of long-term systematic geophysical measurement pioneered modern Earth's magnetic field, geomagnetic and meteorology, meteorological monitoring. Humboldt and Carl Ritter are both regarded as the founders of modern geography as they established it as an independent scientific discipline. Between 1799 and 1804, Humboldt travelled extensively in the Americas, exploring and describing them for the first time from a non-Spanish European scientific point of view. His des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
