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Geothermal Activity
Geothermal activity is a group of natural heat transfer processes, occurring on Earth's surface, caused by the presence of excess heat in the subsurface of the affected area, usually caused by the presence of an igneous intrusion underground. Geothermal activity can manifest itself in a variety of different phenomena, including, among others, elevated surface temperatures, various forms of hydrothermal activity, and the presence of Fumarole, fumaroles that emit hot Volcanic gas, volcanic gases. Background physics Geothermal activity mostly appears in volcanic provinces, where it is fueled by the presence of a magma chamber. In some rare cases it can be caused by Coal-seam fire, underground fires or by large deposits of radioactive elements. Other sources of internal heating can be Planetary differentiation, gravitational differentiation of substances, tidal friction, metamorphism, or phase transitions. The release of heat to the surface occurs either in the form of a conductive h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S04 130 Solfatara, Fumarole
S, or s, is the nineteenth Letter (alphabet), letter of the Latin alphabet, used in the English alphabet, the alphabets of other western Languages of Europe, European languages and other latin alphabets worldwide. Its name in English is English alphabet#Letter names, ''ess'' (pronounced ), plural ''esses''. History Northwest Semitic abjad, Northwest Semitic Shin (letter), šîn represented a voiceless postalveolar fricative (as in 'ip'). It originated most likely as a pictogram of a tooth () and represented the phoneme via the acrophonic principle. Ancient Greek did not have a "sh" phoneme, so the derived Greek letter Sigma (letter), Sigma () came to represent the voiceless alveolar sibilant . While the letter shape Σ continues Phoenician ''šîn'', its name ''sigma'' is taken from the letter ''Samekh'', while the shape and position of ''samekh'' but name of ''šîn'' is continued in the ''Ξ, xi''. Within Greek, the name of ''sigma'' was influenced by its associatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Cauldron
Ice cauldrons are ice formations within glaciers that cover some subglacial volcanoes. They can have circular to oblong forms. Their surface areas reach from some meters (as indentations or holes in the ice) to up to 1 or more kilometers (as bowl shaped depressions). Their existence is connected to ice-volcano interaction in two possible ways: They can be formed in the course of a subglacial eruption or on top of a continuously active subglacial high temperature geothermal area. In both cases, a jökulhlaup may be produced in connection with them. Formation and continued existence of ice cauldrons Ice cauldrons and subglacial eruptions When an eruption takes place under a bigger glacier, e.g. an ice cap, it normally begins with an effusive stage. The heat forms an ice cave and pillow lava is produced. After some time, the eruption has reached a stage where the pressure drops within the ice vault and the eruption style changes to become explosive. Hyaloclastite is produce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Explosions
Hydrothermal explosions occur when superheated water trapped below the surface of the Earth rapidly converts from liquid to steam, violently disrupting the confining rock. Boiling water, steam, mud, and rock fragments are ejected over an area of a few meters up to several kilometers in diameter. Although the energy originally comes from a deep igneous source, this energy is transferred to the surface by circulating meteoric water or mixtures of meteoric and magmatic water rather than by magma, as occurs in volcanic eruptions. The energy is stored as heat in hot water and rock within a few hundred feet of the surface. Hydrothermal explosions are caused by the same instability and chain reaction mechanism as geysers but are so violent that rocks and mud are expelled along with water and steam. Cause Hydrothermal explosions occur where shallow interconnected reservoirs of water at temperatures as high as 250 °C underlie thermal fields. Water usually boils at 100 °C, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mudpot
A mudpot, or mud pool, is a type of acidic hot spring, or fumarole, with limited water. It usually takes the form of a pool of bubbling mud, as a result of the acid and microorganisms decomposing surrounding rock into clay and mud. Description The mud of a mudpot takes the form of a Viscosity, viscous, often bubbling, slurry. As the boiling mud is often squirted over the brims of the mudpot, a form resembling a mini-volcano of mud starts to build up, sometimes reaching heights of . Although mudpots are often called "mud volcanoes", true mud volcanoes are very different in nature. The mud of a mudpot is generally of white to greyish color, but is sometimes stained with reddish or pink spots from iron compounds. When the slurry is particularly colorful, the feature may be referred to as a paint pot. Geology Mudpots form in high-temperature Geothermal activity, geothermal areas where water supply is short. The little water that is available rises to the surface at a spot where the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Park Service
The National Park Service (NPS) is an List of federal agencies in the United States, agency of the Federal government of the United States, United States federal government, within the US Department of the Interior. The service manages all List of national parks of the United States, national parks; most National monument (United States), national monuments; and other natural, historical, and recreational properties, with various title designations. The United States Congress created the agency on August 25, 1916, through the National Park Service Organic Act. Its headquarters is in Washington, D.C., within the main headquarters of the Department of the Interior. The NPS employs about 20,000 people in units covering over in List of states and territories of the United States, all 50 states, the District of Columbia, and Territories of the United States, US territories. In 2019, the service had more than 279,000 volunteers. The agency is charged with preserving the ecological a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geysers
A geyser (, ) is a spring with an intermittent water discharge ejected turbulently and accompanied by steam. The formation of geysers is fairly rare and is caused by particular hydrogeological conditions that exist only in a few places on Earth. Generally, geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Surface water works its way down to an average depth of around where it contacts hot rocks. The pressurized water boils, and this causes the geyser effect of hot water and steam spraying out of the geyser's surface vent. A geyser's eruptive activity may change or cease due to ongoing deposition of minerals within their plumbing, exchange of functions with nearby hot springs, earthquake influences, and human intervention. Like many other natural phenomena, geysers are not unique to Earth. Jet-like eruptions, often called cryogeysers, have been observed on several of the moons of the outer Solar System. Due t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Geysir (2)
Geysir (), sometimes known as The Great Geysir, is a geyser in south-western Iceland, that geological studies suggest started forming about 1150 CE. The English word ''wiktionary:geyser, geyser'' (a periodically spouting hot spring) derives from Geysir. The name ''Geysir'' itself is derived from the Icelandic language, Icelandic verb ''wiktionary:geysa, geysa'' ("to go quickly forward"). Geysir lies in the Haukadalur (Bláskógabyggð), Haukadalur valley on the slopes of Laugarfjall lava dome, which is also the home to Strokkur geyser about to the south. The Strokkur geyser may be confused with it, and the geothermal field it is in is known usually as either, Geysir or Haukadalur. Eruptions at Geysir can typically hurl boiling water up to in the air. However, eruptions are nowadays infrequent, and have in the past stopped altogether for many years at a time. History A geyser at the general site is described in a written source by Saxo Grammaticus, as a mention in Gesta Danorum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crevasse
A crevasse is a deep crack that forms in a glacier or ice sheet. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two semi-rigid pieces above a plastic substrate have different rates of movement. The resulting intensity of the shear stress causes a breakage along the faces. Description Crevasses often have vertical or near-vertical walls, which can then melt and create seracs, arches, and other ice formations. These walls sometimes expose layers that represent the glacier's stratigraphy. Crevasse size often depends upon the amount of liquid water present in the glacier. A crevasse may be as deep as and as wide as The presence of water in a crevasse can significantly increase its penetration. Water-filled crevasses may reach the bottom of glaciers or ice sheets and provide a direct hydrologic connection between the surface, where significant summer melting occurs, and the bed of the glacier, where additional wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Cap
In glaciology, an ice cap is a mass of ice that covers less than of land area (usually covering a highland area). Larger ice masses covering more than are termed ice sheets. Description By definition, ice caps are not constrained by topographical features (i.e., they must lie over the top of mountains). By contrast, ice masses of similar size that ''are'' constrained by topographical features are known as ice fields. The ''dome'' of an ice cap is usually centred on the highest point of a massif. Ice flows away from this high point (the ice divide) towards the ice cap's periphery. Ice caps significantly affect the geomorphology of the area they occupy. Plastic moulding, gouging and other glacial erosional features become present upon the glacier's retreat. Many lakes, such as the Great Lakes in North America, as well as numerous valleys have been formed by glacial action over hundreds of thousands of years. The Antarctic and Greenland contain 99% of the ice volume on earth, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma Chamber
A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it upwards. If the magma finds a path to the surface, then the result will be a volcanic eruption; consequently, many volcanoes are situated over magma chambers. These chambers are hard to detect deep within the Earth, and therefore most of those known are close to the surface, commonly between 1 km and 10 km down. Dynamics of magma chambers Magma rises through cracks from beneath and across the crust because it is less dense than the surrounding rock. When the magma cannot find a path upwards it pools into a magma chamber. These chambers are commonly built up over time, by successive horizontal or vertical magma injections. The influx of new magma causes reaction of pre-existing crystals and the pressure in the chamber to increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Intrusion
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained ( phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
