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Denivation
Niveo-aeolian or cryo-aeolian deposition is the process by which fine-grained sediments are transported by wind and deposited on or mixed with snow or ice. The wind sweeps the snow and sand grains into aeolian landforms such as ripples, and further sorts the snow and ice grains into distinct layers. When snow melts or sublimates, the sediments are redeposited onto the surface below., forming patterns known as denivation features. Niveo-aeolian deposition is most widespread in polar climates, but may be found anywhere that is at least seasonally below freezing. In most places, much or all of the snow in these niveo-aeolian deposits melts in the spring or summer. However, "perennial" niveo-aeolian deposits have been observed in Antarctica's Victoria Valley. Initially, after the wind has deposited it, the surface of a niveo-aeolian deposit typically consists of a rippled bedform of mixed sand and snow. Beneath the surface, the deposits commonly consist of alternating layers of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand And Snow Interlayered
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz. Calcium carbonate is the second most common type of sand, for example, aragonite, which has mostly been created, over the past 500million years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Somewhat more rarely, sand may be composed of calcium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaiser Crater
''Kaiser'' is the German word for "emperor" (female Kaiserin). In general, the German title in principle applies to rulers anywhere in the world above the rank of king (''König''). In English, the (untranslated) word ''Kaiser'' is mainly applied to the emperors of the unified German Empire (1871–1918) and the emperors of the Austrian Empire (1804–1918). During the First World War, anti-German sentiment was at its zenith; the term ''Kaiser''—especially as applied to Wilhelm II, German Emperor—thus gained considerable negative connotations in English-speaking countries. Especially in Central Europe, between northern Italy and southern Poland, between western Austria and western Ukraine and in Bavaria, Emperor Franz Joseph I is still associated with "Der Kaiser (the emperor)" today. As a result of his long reign from 1848 to 1916 and the associated Golden Age before the First World War, this title often has still a very high historical respect in this geographical area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolian Landforms
Aeolian commonly refers to things related to either of two Greek mythological figures: * Aeolus (son of Hippotes), ruler of the winds * Aeolus (son of Hellen), son of Hellen and eponym of the Aeolians * Aeolians, an ancient Greek tribe thought to be descended from Aeolus, son of Hellen Aeolian or Eolian may also refer to: Music * ''Aeolian'' (album), an album by German post-metal band The Ocean Collective * Aeolian Company (1887–1985), a maker of organs, pianos, sheet music, and phonographs * Aeolian Hall (other), any one of a number of concert halls of that name * Aeolian harp, a harp that is played by the wind * Aeolian mode, a musical mode, the natural minor key * Aeolian Quartet (1952–1981), a string quartet based in London * Aeolian-Skinner (1932–1972), pipe organ builder Other uses * Aeolian dialect, a dialect of Ancient Greek * Aeolian Islands, islands in the Tyrrhenian Sea, named after Aeolus the ruler of the winds * Aeolian or Aeolic order, an early or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowdrift
A snowdrift is a deposit of snow sculpted by wind into a mound during a snowstorm. Snowdrifts resemble sand dunes and are formed in a similar manner, namely, by wind moving light snow and depositing it when the wind has virtually stopped, usually against a stationary object. Snow normally crests and slopes off toward the surface on the windward side of a large object. On the leeward side, areas near the object are a bit lower than surrounding areas, but are generally flatter. The impact of snowdrifts on transportation can be more significant than the snowfall itself, such as in the USA during the Great Blizzard of 1978. Snowdrifts are many times found at or on roads, as the crest of the roadbed or the furrows along the road create the disruption to the wind needed to shed its carried snow. Snow fences may be employed on the windward side of the road to intentionally create a drift before the snow-laden wind reaches the road. Photo gallery File:Long Mynd snowdrift.jpeg, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palsa
Palsas are peat mounds with a permanently frozen peat and mineral soil core. They are a typical phenomenon in the polar and subpolar zone of discontinuous permafrost. One of their characteristics is having steep slopes that rises above the mire surface. This leads to the accumulation of large amounts of snow around them. The summits of the palsas are free of snow even in winter, because the wind carries the snow and deposits on the slopes and elsewhere on the flat mire surface. Palsas can be up to 150 m in diameter and can reach a height of 12 m. Permafrost is found on palsa mires only in the palsas themselves, and its formation is based on the physical properties of peat. Dry peat is a good insulator, but wet peat conducts heat better, and frozen peat is even better at conducting heat. This means that cold can penetrate deep into the peat layers, and that heat can easily flow from deeper wet layers in winter. Whereas the dry peat on the palsa surface insulates the frozen co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirt Cone
Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debris: scattered pieces of waste or remains * Dust: a general powder of Organic matter, organic or Mineral, mineral matter * wikt:filth, Filth: foul matter such as excrement * wikt:grime, Grime: a black, ingrained dust such as soot * Soil: the mix of clay, sand, and humus which lies on top of bedrock. The term 'soil' may be used to refer to unwanted substances or dirt that are deposited onto surfaces such as clothing. Exhibitions and studies A season of artworks and exhibits on the theme of dirt was sponsored by the Wellcome Trust in 2011. The centrepiece was an exhibition at the Wellcome Collection showing pictures and histories of notable dirt such as the great dust heaps at Euston railway station, Euston and London King's Cross railway station, King's Cross in the 19th century and the Fresh Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debris Flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally have bulk densities comparable to those of rock avalanches and other types of landslides (roughly 2000 kilograms per cubic meter), but owing to widespread sediment liquefaction caused by high pore-fluid pressures, they can flow almost as fluidly as water. Debris flows descending steep channels commonly attain speeds that surpass 10 m/s (36 km/h), although some large flows can reach speeds that are much greater. Debris flows with volumes ranging up to about 100,000 cubic meters occur frequently in mountainous regions worldwide. The largest prehistoric flows have had volumes exceeding 1 billion cubic meters (i.e., 1 cubic kilometer). As a result of their high sediment concentrations and mobility, debris flows can be very des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hummock
In geology, a hummock is a small knoll or mound above ground.Bates, Robert L. and Julia A. Jackson, ed. (1984). “hummock.” Dictionary of Geological Terms, 3rd Ed. New York: Anchor Books. p. 241. They are typically less than in height and tend to appear in groups or fields. Large landslide avalanches that typically occur in volcanic areas are responsible for formation of hummocks. From the initiation of the landslide to the final formation, hummocks can be characterized by their evolution, spatial distribution, and internal structure. As the movement of landslide begins, the extension faulting results in formation of hummocks with smaller ones at the front of the landslide and larger ones in the back. The size of the hummocks is dependent on their position in the initial mass. As this mass spreads, the hummocks further modify to break up or merger to form larger structures. It is difficult to make generalizations about hummocks because of the diversity in their morphology an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermokarst
Thermokarst is a type of terrain characterised by very irregular surfaces of marshy hollows and small hummocks formed as ice-rich permafrost thaws. The land surface type occurs in Arctic areas, and on a smaller scale in mountainous areas such as the Himalayas and the Swiss Alps. These pitted surfaces resemble clusters of small lakes formed by dissolution of limestone in some karst areas, which is how they came to have "''karst''" attached to their name, even though no limestone is actually present. Small domes that form on the surface due to frost heaving with the onset of winter are only temporary features. They collapse during the following summer thaw, leaving a small surface depression. Some ice lenses grow and form larger surface hummocks ("pingos") which can last for many years, and sometimes become covered with grasses and sedges, until they begin to thaw. These domed surfaces eventually collapse – either annually or after longer periods – and form depressions which bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slump (geology)
A slump is a form of mass wasting that occurs when a coherent mass of loosely consolidated materials or a rock layer moves a short distance down a Grade_(slope), slope. Movement is characterized by sliding along a concave-upward or planar surface. Causes of slumping include Earthquake, earthquake shocks, thorough wetting, freezing and thawing, undercutting, and loading of a slope. Translational slumps occur when a detached landmass moves along a planar surface. Common planar surfaces of failure include joints or bedding planes, especially where a permeable layer overrides an impermeable surface. Block slumps are a type of translational slump in which one or more related block units move downslope as a relatively coherent mass. A rotational slump occurs when a slump block, composed of sediment or rock, slides along a concave-upward slip surface with rotation about an axis parallel to the slope. Rotational movement causes the original surface of the block to become less steep, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand Covered Shelf Ice Starts To Crumble
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a soil texture, textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz. Calcium carbonate is the second most common type of sand, for example, aragonite, which has mostly been created, over the past 500million years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Somewhat more rarely, sand may be compose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Kobuk Sand Dunes
Kobuk Valley National Park is an American national park in the Arctic region of northwestern Alaska, located about north of the Arctic Circle. The park was designated in 1980 by the Alaska National Interest Lands Conservation Act to preserve the high Great Kobuk Sand Dunes and the surrounding area which includes caribou migration routes. Park visitors must bring all their own gear for backcountry camping, hiking, backpacking, boating, and dog sledding. No designated trails or roads exist in the park, which at , is slightly larger than the state of Delaware. Kobuk Valley is one of eight national parks in Alaska, the state with the second most national parks, surpassed only by California which has nine. The park is managed by the National Park Service. Since no roads lead into the park, visitors arrive via chartered air taxi from Nome, Bettles, or Kotzebue. Flights are available year-round, but are weather dependent. The park is one of the least-visited American national parks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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