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Aeolian Processes
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts. The term is derived from the name of the Greek god Aeolus, the keeper of the winds. Definition and setting ''Aeolian processes'' are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as ''aeolian''. Aeolian processes are most important in areas where there is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Outwash
An outwash plain, also called a sandur (plural: ''sandurs''), sandr or sandar, is a plain formed of glaciofluvial deposits due to meltwater outwash at the terminus of a glacier. As it flows, the glacier grinds the underlying rock surface and carries the debris along. The meltwater at the snout of the glacier deposits its load of sediment over the outwash plain, with larger boulders being deposited near the terminal moraine, and smaller particles travelling further before being deposited. Sandurs are common in Iceland where geothermal activity accelerates the melting of ice flows and the deposition of sediment by meltwater. Formation Sandurs are found in glaciated areas, such as Svalbard, Kerguelen Islands, and Iceland. Glaciers and icecaps contain large amounts of silt and sediment, picked up as they erode the underlying rocks when they move slowly downhill, and at the snout of the glacier, meltwater can carry this sediment away from the glacier and deposit it on a broad p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entrainment (physical Geography)
In physical geography, entrainment is the process by which surface sediment is incorporated into a fluid flow (such as air, water or even ice) as part of the operation of erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is dis ....Thomas,D.S.G. and Goudie, A. (Eds.), ''The Dictionary of Physical Geography'' (3rd edition), Blackwell Publishers, Great Britain, 2000 References Physical geography {{geo-term-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandblasting
Sandblasting, sometimes known as abrasive blasting, is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface or remove surface contaminants. A pressurised fluid, typically compressed air, or a centrifugal wheel is used to propel the blasting material (often called the ''media''). The first abrasive blasting process was patented by Benjamin Chew Tilghman on 18 October 1870. There are several variants of the process, using various media; some are highly abrasive, whereas others are milder. The most abrasive are shot blasting (with metal shot) and sandblasting (with sand). Moderately abrasive variants include glass bead blasting (with glass beads) and plastic media blasting (PMB) with ground-up plastic stock or walnut shells and corncobs. Some of these substances can cause anaphylactic shock to individuals allergic to the media. A mild version is sodablast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventifact
A ventifact (also wind-faceted stone, windkanter) is a rock that has been abraded, pitted, etched, grooved, or polished by wind-driven sand or ice crystals. These geomorphic features are most typically found in arid environments where there is little vegetation to interfere with aeolian particle transport, where there are frequently strong winds, and where there is a steady but not overwhelming supply of sand. Ventifacts can be abraded to eye-catching natural sculptures such as the main features of the White Desert National Park near Farafra oasis in Egypt. In moderately tall, isolated rock outcrops, mushroom shaped pillars of rock may form as the outcrop is eroded by saltating sand grains. This occurs because, even in strong winds, sand grains can't be continuously held in the air. Instead, the particles bounce along the ground, rarely reaching higher than a few feet above the Earth. Over time, the bouncing sand grains can erode the lower portions of a ventifact, while leavin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between those layers. Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in engineering applications are turbulent. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. This increases the energy needed to pump fluid through a pipe. The onset of turbulence can be predicted by the dimensionless Rey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Erosion
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts. The term is derived from the name of the Greek god Aeolus, the keeper of the winds. Definition and setting ''Aeolian processes'' are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as ''aeolian''. Aeolian processes are most important in areas where there is little ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolian Erosion
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts. The term is derived from the name of the Greek god Aeolus, the keeper of the winds. Definition and setting ''Aeolian processes'' are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as ''aeolian''. Aeolian processes are most important in areas where there is little o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkansas River
The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in the western United States in Colorado, specifically the Arkansas River Valley. The headwaters derive from the snowpack in the Sawatch and Mosquito mountain ranges. It flows east into the Midwest via Kansas, and finally into the South through Oklahoma and Arkansas. At , it is the sixth-longest river in the United States, the second-longest tributary in the Mississippi–Missouri system, and the 45th longest river in the world. Its origin is in the Rocky Mountains in Lake County, Colorado, near Leadville. In 1859, placer gold discovered in the Leadville area brought thousands seeking to strike it rich, but the easily recovered placer gold was quickly exhausted. The Arkansas River's mouth is at Napoleon, Arkansas, and its drainage basin covers nearly .See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platte River
The Platte River () is a major river in the State of Nebraska. It is about long; measured to its farthest source via its tributary, the North Platte River, it flows for over . The Platte River is a tributary of the Missouri River, which itself is a tributary of the Mississippi River which flows to the Gulf of Mexico. The Platte over most of its length is a broad, shallow, meandering stream with a sandy bottom and many islands—a braided stream. The Platte is one of the most significant tributary systems in the watershed of the Missouri, draining a large portion of the central Great Plains in Nebraska and the eastern Rocky Mountains in Colorado and Wyoming. The river valley played an important role in the westward expansion of the United States, providing the route for several major emigrant trails, including the Oregon, California, Mormon and Bozeman trails. The first Europeans to see the Platte were French explorers and fur trappers about 1714; they first called it the ''N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
