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Lava Tubes
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] |
Valentine Cave
Valentine Cave is a cave found in Lava Beds National Monument, California. It is considered one of the least challenging caves in the park. Discovery and name The cave is one of the few in the park not named by J. D. Howard. It was discovered by Ross R. Musselman on Valentine's Day in 1933. He was led to the entrance after he noticed steam rising up from afar. As the discoverer, he was awarded naming rights. He named it after the day of discovery. Musselman later regretted his naming decision, wishing the cave bore his eponym instead. Description Valentine Cave is approximately 11,000 years old with a roof thick. It is considered a "warm cave", as interior temperatures remain around . On very cold days, such as on the day of its discovery, steam may rise from the entrance. The accessible passages within the cave total . Most of the accessible area is in one main tube, blocked downstream from the entrance by lava. The Valentine Cave entrance is a shallow collapse pit with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helictite
A helictite is a speleothem (cave-formed mineral) found in a Solution cave, limestone cave that changes its axis from the vertical at one or more stages during its growth. Helictites have a curving or angular form that looks as if they were grown in zero gravity. They are most likely the result of Capillary action, capillary forces acting on tiny water droplets, a force often strong enough at this scale to defy gravity. Helictites are, perhaps, the most delicate of cave formations. They are usually made of needle-form calcite and aragonite. Helictite forms have been described in several types: ribbon helictites, saws, rods, butterflies, "hands", curly-fries, and "clumps of worms". They typically have symmetry (biology)#Radial symmetry, radial symmetry. They can be easily crushed or broken by the slightest touch. Because of this, helictites are rarely seen within arm's reach in Tourism, tourist caves. Timpanogos Cave National Monument in Utah has one of the largest collections o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Lava Tube
file:Mare Tranquillitatis pit crater.jpg, The Mare Tranquillitatis pit has been associated with a lava tube. Lunar lava tubes are lava tubes on the Moon formed during the eruption of Basalt, basaltic lava flows. When the surface of a lava flow cools, it hardens and the lava can channel beneath the surface in a tube-shaped passage. Once the flow of lava diminishes, the tube may drain, forming a hollow void. Lunar lava tubes are formed on sloped surfaces that range in angle from 0.4° to 6.5°. These tubes may be as wide as before they become unstable against lunar gravity, gravitational collapse. However, stable tubes may still be disrupted by seismic events or meteoroid bombardment. The existence of a lava tube is sometimes revealed by the presence of a "skylight", a place in which the roof of the tube has collapsed, leaving a circular hole that can be observed by lunar orbiters. Observational evidence An area displaying a lava tube and rilles is the Marius Hills region (). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial
Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance (geometry), a directional coordinate in a polar coordinate system * Radial set * A bearing from a waypoint, such as a VHF omnidirectional range Biology * Radial artery, the main artery of the lateral aspect of the forearm * Radial nerve, supplies the posterior portion of the upper limb * Radial symmetry, one of the types of distribution of body parts or shapes in biology * Radius (bone), a bone of the forearm Technology * Radial (radio), lines which radiate from a radio antenna * Radial axle, on a locomotive or carriage * Radial compressor * Radial delayed blowback * Radial engine * Radial tire A radial tire (more properly, a radial-ply tire) is a particular design of vehicular tire. In this design, the cord plies are arranged at 90 degrees to the direction of travel, or radially (from the center of the tire). Ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concentric
In geometry, two or more objects are said to be ''concentric'' when they share the same center. Any pair of (possibly unalike) objects with well-defined centers can be concentric, including circles, spheres, regular polygons, regular polyhedra, parallelograms, cones, conic sections, and quadrics. Geometric objects are '' coaxial'' if they share the same axis (line of symmetry). Geometric objects with a well-defined axis include circles (any line through the center), spheres, cylinders, conic sections, and surfaces of revolution. Concentric objects are often part of the broad category of '' whorled patterns'', which also includes '' spirals'' (a curve which emanates from a point, moving farther away as it revolves around the point). Geometric properties In the Euclidean plane, two circles that are concentric necessarily have different radii from each other.. However, circles in three-dimensional space may be concentric, and have the same radius as each other, but nevert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columnar Jointing
Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as Joint (geology), joints, result in the formation of a regular array of polygonal Prism (geometry), prisms, or columns. Columnar jointing occurs in many types of igneous rocks (e.g. basalt, andesite, rhyolite), and forms as the rock cools and contracts. Columnar jointing can occur in cooling lava flows and ashflow tuffs (ignimbrites), as well as in some shallow intrusions. Columnar jointing also occurs rarely in sedimentary rocks, due to a combination of Solution_(chemistry), dissolution and Precipitation_(chemistry), reprecipitation of interstitial minerals (often quartz or cryptocrystalline silica) by hot, hydrothermal fluids and the expansion and contraction of the rock unit, both resulting from the presence of a nearby Igneous intrusion, magmatic intrusion. The columns can vary from 3 meters to a few centimeters in diameter, and can be as much as 30 meters tall. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller islands. It has a total area of , making it the list of countries and dependencies by area, sixth-largest country in the world and the largest in Oceania. Australia is the world's flattest and driest inhabited continent. It is a megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and Climate of Australia, climates including deserts of Australia, deserts in the Outback, interior and forests of Australia, tropical rainforests along the Eastern states of Australia, coast. The ancestors of Aboriginal Australians began arriving from south-east Asia 50,000 to 65,000 years ago, during the Last Glacial Period, last glacial period. By the time of British settlement, Aboriginal Australians spoke 250 distinct l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiama, New South Wales
Kiama () is a coastal town 120 kilometres south of Sydney in the Illawarra region of New South Wales, Australia. One of the main tourist attractions is the Kiama Blowhole. Kiama features several popular surfing beaches and caravan parks, and numerous alfresco cafes and restaurants. Its proximity to the south of Sydney makes it an attractive destination for many day-trippers and weekenders. Kiama also has historically been a farming and agricultural centre. Even to today it maintains a country and agricultural community with a weekly farmers markets held on Wednesday afternoons. History Kiama was the site of two strong volcanic flows, called the Gerringong Volcanics, which came out of Saddleback Mountain (New South Wales), Saddleback Mountain, now a collapsed volcanic vent. The Kiama Blowhole is part of an erosion process on the more recent rock, formed into columnar basalt, or latite. Before the cedar-getters (comprising ex-convicts, convicts and runaways, some with cedar licen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tenerife
Tenerife ( ; ; formerly spelled ''Teneriffe'') is the largest and most populous island of the Canary Islands, an Autonomous communities of Spain, autonomous community of Spain. With a land area of and a population of 965,575 inhabitants as of April 2025, it is the most populous island in Spain and the entire Macaronesia region. Tenerife is also home to 42.7% of the total population of the archipelago. More than seven million tourists (7,384,707 in 2024) visit Tenerife each year, making it by far the most visited island in the archipelago. It is one of the most important tourist destinations in Spain and the world, hosting one of the world's largest carnivals, the Carnival of Santa Cruz de Tenerife. The capital of the island, , is also the seat of the island council (). That city and are the co-capitals of the Autonomous communities of Spain, autonomous community of the Canary Islands. The two cities are both home to governmental institutions, such as the offices of the preside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icod De Los Vinos
Icod de los Vinos is a municipality in the province of Santa Cruz de Tenerife on the island of Tenerife, in the Canary Islands (Spain), located in the northwestern part of the island. Inhabitants of Icod are known in Spanish as ''"icodenses"''. Icod has an area of , is situated at an altitude of above sea level, and had a population of 23,496 in 2022.Instituto Canario de Estadística Location Icod de los Vinos is located on a continuous smooth slope that stretches from the extensive of[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauna Loa
Mauna Loa (, ; ) is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean. Mauna Loa is Earth's largest active volcano by both mass and volume. It was historically considered to be the largest volcano on Earth until the submarine mountain Tamu Massif was discovered to be larger. Mauna Loa is a shield volcano with relatively gentle slopes, and a volume estimated at , although its peak is about lower than that of its neighbor, Mauna Kea. Lava eruptions from Mauna Loa are silica-poor and very fluid, and tend to be non-explosive. Mauna Loa has likely been erupting for at least 700,000 years, and may have emerged above sea level about 400,000 years ago. Some dated rocks are 470,000 years old. The volcano's magma comes from the Hawaii hotspot, which has been responsible for the creation of the Hawaiian Island chain over tens of millions of years. The slow drift of the Pacific Plate will eventually carry Mauna Lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
