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Ice Wedging
Frost weathering is a collective term for several mechanical weathering processes induced by stresses created by the freezing of water into ice. The term serves as an umbrella term for a variety of processes, such as frost shattering, frost wedging, and cryofracturing. The process may act on a wide range of spatial and temporal scales, from minutes to years and from dislodging mineral grains to fracturing boulders. It is most pronounced in high-altitude and high-latitude areas and is especially associated with alpine, periglacial, subpolar maritime, and polar climates, but may occur anywhere at sub-freezing temperatures (between ) if water is present. Ice segregation Certain frost-susceptible soils expand or heave upon freezing as a result of water migrating via capillary action to grow ice lenses near the freezing front. This same phenomenon occurs within pore spaces of rocks. The ice accumulations grow larger as they attract liquid water from the surrounding pores. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petroleum
Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring unprocessed crude oil, as well as to petroleum products that consist of refining, refined crude oil. Petroleum is a fossil fuel formed over millions of years from anaerobic decay of organic materials from buried prehistoric life, prehistoric organisms, particularly planktons and algae, and 70% of the world's oil deposits were formed during the Mesozoic. Conventional reserves of petroleum are primarily recovered by oil drilling, drilling, which is done after a study of the relevant structural geology, sedimentary basin analysis, analysis of the sedimentary basin, and reservoir characterization, characterization of the petroleum reservoir. There are also unconventional (oil & gas) reservoir, unconventional reserves such as oil sands and oil sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar, because they are the most resistant minerals to the weathering processes at the Earth's surface. Like uncemented sand, sandstone may be imparted any color by impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Because sandstone beds can form highly visible cliffs and other topography, topographic features, certain colors of sandstone have become strongly identified with certain regions, such as the red rock deserts of Arches National Park and other areas of the Southwestern United States, American Southwest. Rock formations composed of sandstone usually allow the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solifluction
Solifluction is a collective name for gradual processes in which a mass moves down a slope ("mass wasting") related to freeze-thaw activity. This is the standard modern meaning of solifluction, which differs from the original meaning given to it by Johan Gunnar Andersson Johan Gunnar Andersson (3 July 1874 – 29 October 1960)"Andersson, Johan Gunnar" in '' The New Encyclopædia Britannica''. Chicago: Encyclopædia Britannica Inc., 15th edn., 1992, Vol. 1, p. 385. was a Swedish archaeologist, geomorphologist, ... in 1906. Origin and evolution of the concept In the original sense it meant the movement of waste saturated in water found in periglaciation, periglacial regions. However it was later discovered that various slow waste movements in periglacial regions did not require saturation in water, but were rather associated to freeze-thaw processes. The term solifluction was appropriated to refer to these slow processes, and therefore excludes rapid periglacial movements. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bratschen
''Bratschen'' are weathering products that occur as a result of frost weathering, frost and aeolian processes, aeolian corrasion almost exclusively on the calc-schists of the Upper Slate Mantle (''Obere Schieferhülle'') in the High Tauern mountains of Austria. The term is German but is used untranslated in English sources. The calc-schist, which appears blue-gray when freshly broken, weathers to a yellow to brown colour and flakes off on the surface to form ''bratschen''. These form steep (up to 40°), rocky, almost unvegetated mountainsides with an odd and rough-textured surface, caused by wind erosion. ''Bratschen'' are found on the mountains such as the Fuscherkarkopf, the Großer Bärenkopf, the Kitzsteinhorn, the Schwerteck, or on the eponymous Bratschenkopf, Bratschenköpfen. References Sources * {{Periglacial environment Geomorphology Hohe Tauern Geology of the Alps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weathering
Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no movement), and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity. Weathering processes are either physical or chemical. The former involves the breakdown of rocks and soils through such mechanical effects as heat, water, ice and wind. The latter covers reactions to water, atmospheric gases and biologically produced chemicals with rocks and soils. Water is the principal agent behind both kinds, though atmospheric oxygen and carbon dioxide and the activities of biological organisms are also important. Biological chemical weathering is also called biological weathering. The materials left after the rock breaks down combine with organic material to create so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pore Water Pressure
Pore water pressure (sometimes abbreviated to pwp) refers to the pressure of groundwater held within a soil or Rock (geology), rock, in gaps between particles (soil pore, pores). Pore water pressures below the phreatic level of the groundwater are measured with piezometers. The vertical pore water pressure distribution in aquifers can generally be assumed to be close to Hydrostatic pressure, hydrostatic. In the Vadose zone , unsaturated ("vadose") zone, the pore pressure is determined by capillary action, capillarity and is also referred to as Tension (physics), tension, suction, or matric pressure. Pore water pressures under unsaturated conditions are measured with Tensiometer (soil science), tensiometers, which operate by allowing the pore water to come into equilibrium with a reference pressure indicator through a permeable ceramic cup placed in contact with the soil. Pore water pressure is vital in calculating the stress state in the ground soil mechanics, from Karl von Terzag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Jacking
Ice jacking occurs when water permeates a confined space within a structural support or a geological formation, ultimately causing structural fracture when the water freezes and expands. The force from this expansion can damage shorelines, rock faces, and other natural environments. This has the potential to lead to property damage and environmental changes. Ice jacking most commonly refers to shoreline damage caused by lakes freezing, but it has also been applied to geologic engineering and rock erosion. When this occurs within rocks, it is called ice wedging. When this occurs within the soil, it is called frost heaving or ice heaving. It is similar in appearance to, but not to be confused with, ice shove, which is a pile-up of ice on a shoreline. Lakes and shorelines Ice jacking is a continuous process that occurs during the winter in areas near lakes. The process starts when the ice begins to crack. When water then fills in those gaps, the process repeats and continues unti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrostatic Pressure
Hydrostatics is the branch of fluid mechanics that studies fluids at hydrostatic equilibrium and "the pressure in a fluid or exerted by a fluid on an immersed body". The word "hydrostatics" is sometimes used to refer specifically to water and other liquids, but more often it includes both gases and liquids, whether Compressible flow, compressible or Incompressible flow, incompressible. It encompasses the study of the conditions under which fluids are at rest in Mechanical equilibrium, stable equilibrium. It is opposed to ''fluid dynamics'', the study of fluids in motion. Hydrostatics is fundamental to ''hydraulics'', the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics (for example, in understanding plate tectonics and the anomalies of the Gravity of Earth, Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields. Hydrostatics offers physical expl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. The journal is considered one of the most prestigious in the field of physics. Over a quarter of Physics Nobel Prize-winning papers between 1995 and 2017 were published in it. ''PRL'' is published both online and as a print journal. Its focus is on short articles ("letters") intended for quick publication. The Lead Editor is Hugues Chaté. The Managing Editor is Robert Garisto. History The journal was created in 1958. Samuel Goudsmit, who was then the editor of '' Physical Review'', the American Physical Society's flagship journal, organized and published ''Letters to the Editor of Physical Review'' into a new standalone journal'','' which became ''Physical Review Letters''. It was the first journal intended for the rapid publication of short articles, a format that eventually became popular in many other fiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'' is the peer review, peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' cover the full range of List of academ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature Geoscience
''Nature Geoscience'' is a monthly peer-reviewed scientific journal published by the Nature Publishing Group. The Chief Editor is Tamara Goldin, who took over from Heike Langenberg in February 2020. It was established in January 2008. Scope The journal covers all aspects of the Earth sciences, including theoretical research, modelling, and field work. Significant related work in other fields, such as atmospheric sciences, geology, geophysics, climatology, oceanography, palaeontology, and space science, is also published. Abstracting and indexing The journal is abstracted and indexed by: * '' CAB Abstracts'' * ''Chemical Abstracts Service/ CASSI'' * ''Science Citation Index'' * ''Current Contents/Physical, Chemical & Earth Sciences'' * '' GeoRef'' According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Gradient
Hydraulic head or piezometric head is a measurement related to liquid pressure (normalized by specific weight) and the liquid elevation above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22, eq.3.2a. It is usually measured as an equivalent liquid surface elevation, expressed in units of length, at the entrance (or bottom) of a piezometer. In an aquifer, it can be calculated from the depth to water in a piezometric well (a specialized water well), and given information of the piezometer's elevation and screen depth. Hydraulic head can similarly be measured in a column of water using a standpipe piezometer by measuring the height of the water surface in the tube relative to a common datum. The hydraulic head can be used to determine a ''hydraulic gradient'' between two or more points. Definition In fluid dynamics, the ''head'' at some point in an incompressible (constant density) flow is equal to the height of a static column of fluid whose pressure at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
