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Subsidence Crater
__NOTOC__ A subsidence crater is a hole or depression left on the surface of an area which has had an underground (usually nuclear) explosion. Many such craters are commonly present at bomb testing areas; one notable example is the Nevada Test Site, which was historically used for nuclear weapons testing over a period of 41 years. Subsidence craters are created as the roof of the cavity caused by the explosion collapses. This causes the surface to depress into a sink (which subsidence craters are sometimes called; see sink hole). It is possible for further collapse to occur from the sink into the explosion chamber. When this collapse reaches the surface, and the chamber is exposed atmospherically to the surface, it is referred to as a ''chimney''. It is at the point that a chimney is formed through which radioactive fallout may reach the surface. At the Nevada Test Site, depths of were used for tests. When the material above the explosion is solid rock, then a mound may be fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huron King Crater 2
Huron may refer to: People * Wyandot people (or Wendat), indigenous to North America * Wyandot language, spoken by them * Huron-Wendat Nation, a Huron-Wendat First Nation with a community in Wendake, Quebec * Nottawaseppi Huron Band of Potawatomi, a band of Potawatomi American Indians, based in Calhoun County, Michigan), are also known as the Huron Potawatomi Bodies of water * Lake Huron, one of the North American Great Lakes * Huron Swamp in Springfield Township, Oakland County, Michigan * Huron Falls, one of 24 named waterfalls in Ricketts Glen State Park in Pennsylvania * Huron Lake, in the parish municipality of Lac-aux-Sables, Mékinac Regional County Municipality, Quebec * Huron River (other) * Rivière des Hurons (other) Places Canada * Lac-Huron, Quebec, an unorganized territory in the Rimouski-Neigette Regional County Municipality * Huron-Kinloss, a township in Bruce County, Ontario * Huron East, Ontario, a municipality in Huron County, Ontario * R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosion Crater
An explosion crater is a type of wikt:crater, crater formed when material is ejected from the surface of the ground by an explosive event at or immediately above or below the surface. A crater is formed by an explosive event through the displacement and ejection of material from the ground. It is typically bowl-shaped. High-pressure gas and shock waves cause three processes responsible for the creation of the crater: * Plastic deformation of the ground. * Projection of material (ejecta) from the ground by the explosion. * Spallation of the ground surface. Two processes partially fill the crater back in: * Fall-back of ejecta. * Erosion and landslides of the crater lip and wall.P. W. Cooper. ''Explosives Engineering''. Wiley-VCH. The relative importance of the five processes varies, depending on the height above or depth below the ground surface at which the explosion occurs and on the composition of the ground. Examples One of the largest explosion craters in Germany is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapons Testing
Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, Nuclear weapon yield, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to Nuclear explosion, nuclear explosions. However, nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most List of countries with nuclear weapons, nuclear weapons states publicly declared their nuclear status through a nuclear test. The first nuclear device was detonated as a test by the United States at the Trinity site in New Mexico on July 16, 1945, with a yield approximately TNT equivalent, equivalent to 20 kilotons of TNT. The first thermonuclear weapon technology test of an engineered device, codenamed "Ivy Mike", was teste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a Volcanic crater, crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish language, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Draft
In meteorology, an updraft is a small-scale current of rising air, often within a cloud. Overview Localized regions of warm or cool air will exhibit vertical movement. A mass of warm air will typically be less dense than the surrounding region, and so will rise until it reaches air that is either warmer or less dense than itself. The converse will occur for a mass of cool air, and is known as subsidence. This movement of large volumes of air, especially when regions of hot, wet air rise, can create large clouds, and is the central source of thunderstorms. Drafts can also be conceived by low or high pressure regions. A low pressure region will attract air from the surrounding area, which will move towards the center and then rise, creating an updraft. A high pressure region will attract air from the surrounding area, which will move towards the center and sink, spawning a downdraft. Updrafts and downdrafts, along with wind shear in general, are a major contributor to airplane cras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block Caving
Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the same techniques used to excavate ores of gems, such as diamonds and rubies. Soft-rock mining refers to the excavation of softer minerals, such as salt, coal, and oil sands. Mine access Underground access Accessing underground ore can be achieved via a decline (ramp), inclined vertical shaft or adit. *Declines can be a spiral tunnel which circles either the flank of the deposit or circles around the deposit. The decline begins with a box cut, which is the portal to the surface. Depending on the amount of overburden and quality of bedrock, a galvanized steel culvert may be required for safety purposes. They may also be started into the wall of an open cut mine. *Shafts are vertical excavations sunk adjacent to an ore body. Shafts are sun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glory Hole (mining)
Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the same techniques used to excavate ores of gems, such as diamonds and rubies. Soft-rock mining refers to the excavation of softer minerals, such as salt, coal, and oil sands. Mine access Underground access Accessing underground ore can be achieved via a decline (ramp), inclined vertical shaft or adit. *Declines can be a spiral tunnel which circles either the flank of the deposit or circles around the deposit. The decline begins with a box cut, which is the portal to the surface. Depending on the amount of overburden and quality of bedrock, a galvanized steel culvert may be required for safety purposes. They may also be started into the wall of an open cut mine. *Shafts are vertical excavations sunk adjacent to an ore body. Shafts are sun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camouflet
A camouflet, in military science, is an artificial cavern created by an explosion. If the explosion reaches the surface then it is called a crater. The term was originally defined as a countermine dug by defenders to prevent the undermining of a fortress's walls during a siege. The defenders would dig a tunnel under the attackers' tunnel. An explosive charge would be detonated to create a camouflet that would collapse the attackers' tunnel. More recently, the term has been used to describe the effects of very large bombs like the Grand Slam bomb, which are designed to penetrate next to a large target structure and create a camouflet to undermine the foundations of the structure. It has been observed that it is more efficient to penetrate ground next to the target than to hit the target directly. A camouflet set describes a system used in the British Army for cratering tracks and other routes. A tube is driven into the ground using a manual post driver. The end of the tube is a d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedan (nuclear Test)
Storax Sedan was a shallow underground nuclear test conducted in Area 10 of Yucca Flat at the Nevada National Security Site on July 6, 1962, as part of Operation Plowshare, a program to investigate the use of nuclear weapons for mining, cratering, and other civilian purposes. The radioactive fallout from the test contaminated more US residents than any other nuclear test. The Sedan Crater is the largest human-made crater in the United States and is listed on the National Register of Historic Places. Effects Sedan was a thermonuclear device with a fission yield less than 30% and a fusion yield about 70%.Information sign at the crater: ''United States Nuclear Tests''; July 1945 through September 1992, DOE/NV--209-REV 15 December 2000, p. xv. According to Carey Sublette, the design of the Sedan device was similar to that used in the Bluestone and Swanee tests of Operation Dominic conducted days and months prior to Sedan respectively, and was therefore not unlike the W56 high yield ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chagan (nuclear Test)
Chagan () was a Soviet underground nuclear test conducted at the Semipalatinsk Test Site on January 15, 1965. Description Chagan was the first and largest of the 124 detonations in the Nuclear Explosions for the National Economy program, designed to produce peaceful nuclear explosions (PNEs) for earth-moving purposes. The concept of using PNEs to create artificial lakes, harbors and canals was modeled after a United States program, Project Plowshare, which conducted the first peaceful nuclear explosion (the 104 kt Sedan shallow cratering test) at the Nevada Test Site in July 1962. Described as a "near clone" of the Sedan shot, Chagan's yield was the equivalent of 140 kilotons of TNT and sought to produce a large conical crater suitable for a lake. The site was a dry bed of the Chagan River (tributary of Irtysh River) at the edge of the Semipalatinsk Test Site, and was chosen such that the lip of the crater would dam the river during its high spring flow. The resultant lake h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underground Nuclear Weapons Testing
Underground nuclear testing is the Nuclear weapons testing, test detonation of nuclear weapons that is performed underground. When the device being tested is buried at sufficient depth, the nuclear explosion may be contained, with no release of radioactive materials to the atmosphere. The extreme heat and pressure of an underground nuclear explosion causes changes in the surrounding rock. The rock closest to the location of the test is vaporised, forming a cavity. Farther away, there are zones of crushed, cracked, and irreversibly strained rock. Following the explosion, the rock above the cavity may collapse, forming a rubble chimney. If this chimney reaches the surface, a bowl-shaped subsidence crater may form. The first underground test took place in 1951; further tests provided information that eventually led to the signing of the Partial Test Ban Treaty, Limited Test Ban Treaty in 1963, which banned all nuclear tests except for those performed underground. From then until th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depression (geology)
In geology, a depression is a landform sunken or depressed below the surrounding area. Depressions form by various mechanisms. Types Erosion-related: * Blowout: a depression created by wind erosion typically in either a partially vegetated sand dune ecosystem or dry soils (such as a post-glacial loess environment). * Glacial valley: a depression carved by erosion by a glacier. * River valley: a depression carved by fluvial erosion by a river. * Area of subsidence caused by the collapse of an underlying structure, such as sinkholes in karst terrain. * Sink: an endorheic depression generally containing a persistent or intermittent (seasonal) lake, a salt flat (playa) or dry lake, or an ephemeral lake. * Panhole: a shallow depression or basin eroded into flat or gently sloping, cohesive rock.Twidale, C.R., and Bourne, J.A., 2018Rock basins (gnammas) revisited.''Géomorphologie: Relief, Processus, Environnement,'' Vol. 24, No. 2. January 2018. Retrieved 9 June 2020. Coll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
