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Equilibrium Line Altitude
Glaciology (; ) is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice. Glaciology is an interdisciplinary Earth science that integrates geophysics, geology, physical geography, geomorphology, climatology, meteorology, hydrology, biology, and ecology. The impact of glaciers on people includes the fields of human geography and anthropology. The discoveries of water ice on the Moon, Mars, Europa and Pluto add an extraterrestrial component to the field, which is referred to as "astroglaciology". Overview A glacier is an extended mass of ice formed from snow falling and accumulating over a long period of time; glaciers move very slowly, either descending from high mountains, as in valley glaciers, or moving outward from centers of accumulation, as in continental glaciers. Areas of study within glaciology include glacial history and the reconstruction of past glaciation. A glaciologist is a person who studies glaciers. A glacial geologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. On Earth, 99% of glacial ice is contained within vast ice sheets (also known as "continental glaciers") in the polar regions, but glaciers may be found in mountain ranges on every continent other than the Australian mainland, including Oceania's high-latitude oceanic island countries such as New Zealand. Between latitudes 35°N and 35°S, glaciers occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europa (moon)
Europa , or Jupiter II, is the smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet of all the 80 known moons of Jupiter. It is also the sixth-largest moon in the Solar System. Europa was discovered in 1610 by Galileo Galilei and was named after Europa, the Phoenician mother of King Minos of Crete and lover of Zeus (the Greek equivalent of the Roman god Jupiter). Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and has a water-ice crust and probably an iron–nickel core. It has a very thin atmosphere, composed primarily of oxygen. Its white- beige surface is striated by light tan cracks and streaks, but craters are relatively few. In addition to Earth-bound telescope observations, Europa has been examined by a succession of space-probe flybys, the first occurring in the early 1970s. In September 2022, the ''Juno'' spacecraft flew within about 200 miles of Europa for a more recent close-up view. Europa has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming. Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Calving
Ice calving, also known as glacier calving or iceberg calving, is the breaking of ice chunks from the edge of a glacier.Essentials of Geology, 3rd edition, Stephen Marshak It is a form of ice ablation or ice disruption. It is the sudden release and breaking away of a mass of ice from a glacier, iceberg, ice front, ice shelf, or crevasse. The ice that breaks away can be classified as an iceberg, but may also be a growler, bergy bit, or a crevasse wall breakaway.Glossary of Glacier Terms Ellin Beltz, 2006. Retrieved July 2009. Calving of glaciers is often accompanied by a loud cracking or booming sound before blocks of ice up to high break loose and crash into the water. The entry of the ice into the water causes large, and often hazardous waves. The waves formed in locations like |
Ablation
Ablation ( la, ablatio – removal) is removal or destruction of something from an object by vaporization, chipping, erosive processes or by other means. Examples of ablative materials are described below, and include spacecraft material for ascent and atmospheric reentry, ice and snow in glaciology, biological tissues in medicine and passive fire protection materials. Artificial intelligence In artificial intelligence (AI), especially machine learning, ablation is the removal of a component of an AI system. The term is by analogy with biology: removal of components of an organism. Biology Biological ablation is the removal of a biological structure or functionality. Genetic ablation is another term for gene silencing, in which gene expression is abolished through the alteration or deletion of genetic sequence information. In cell ablation, individual cells in a population or culture are destroyed or removed. Both can be used as experimental tools, as in loss-of-fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacier Ice Accumulation
Glacier ice accumulation occurs through accumulation of snow and other frozen precipitation, as well as through other means including rime ice (freezing of water vapor on the glacier surface), avalanching from hanging glaciers on cliffs and mountainsides above, and re-freezing of glacier meltwater as superimposed ice. Accumulation is one element in the glacier mass balance formula, with ablation counteracting. With successive years in which accumulation exceeds ablation, then a glacier will experience positive mass balance, and its terminus will advance. Accumulation zones Glaciologists subdivide glaciers into glacier accumulation zones, based on the melting and refreezing occurring. These zones include the dry snow zone, in which the ice entirely retains subfreezing temperatures and no melting occurs. Dry snow zones only occur within the interior regions of the Greenland and Antarctica ice sheets. Below the dry snow zone is the percolation Percolation (from Latin ''percol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegeta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is the world's largest island. It is one of three constituent countries that form the Kingdom of Denmark, along with Denmark and the Faroe Islands; the citizens of these countries are all citizens of Denmark and the European Union. Greenland's capital is Nuuk. Though a part of the continent of North America, Greenland has been politically and culturally associated with Europe (specifically Norway and Denmark, the colonial powers) for more than a millennium, beginning in 986.The Fate of Greenland's Vikings , by Dale Mackenzie Brown, ''Archaeological Institute of Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arête
An arête ( ) is a narrow ridge of rock which separates two valleys. It is typically formed when two glaciers erode parallel U-shaped valleys. Arêtes can also form when two glacial cirques erode headwards towards one another, although frequently this results in a saddle-shaped pass, called a col. The edge is then sharpened by freeze-thaw weathering, and the slope on either side of the arête steepened through mass wasting events and the erosion of exposed, unstable rock. The word ''arête'' () is actually French for "edge" or "ridge"; similar features in the Alps are often described with the German equivalent term ''Grat''. Where three or more cirques meet, a pyramidal peak is created. Cleaver A ''cleaver'' is a type of arête that separates a unified flow of glacial ice from its uphill side into two glaciers flanking, and flowing parallel to, the ridge. ''Cleaver'' gets its name from the way it resembles a meat cleaver slicing meat into two parts. A cleaver may be tho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirque
A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform arising from fluvial erosion. The concave shape of a glacial cirque is open on the downhill side, while the cupped section is generally steep. Cliff-like slopes, down which ice and glaciated debris combine and converge, form the three or more higher sides. The floor of the cirque ends up bowl-shaped, as it is the complex convergence zone of combining ice flows from multiple directions and their accompanying rock burdens. Hence, it experiences somewhat greater erosion forces and is most often overdeepened below the level of the cirque's low-side outlet (stage) and its down-slope (backstage) valley. If the cirque is subject to seasonal melting, the floor of the cirque most often forms a tarn (small lake) behind a dam, which marks the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary science and is concerned with local detail in general, including not only relief, but also natural, artificial, and cultural features such as roads, land boundaries, and buildings. In the United States, topography often means specifically ''relief'', even though the USGS topographic maps record not just elevation contours, but also roads, populated places, structures, land boundaries, and so on. Topography in a narrow sense involves the recording of relief or terrain, the three-dimensional quality of the surface, and the identification of specific landforms; this is also known as geomorphometry. In modern usage, this involves generation of elevation data in digital form ( DEM). It is often considered to include the graphic representa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
