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Laguna Vilama
Laguna Vilama is a salt lake in northwestern Argentina, within the Vilama caldera. It is shallow and covers a surface area of . Lake Laguna Vilama lies in the Jujuy Province of Argentina, close to the Sur Lípez Province of Bolivia and to the tripoint with Chile, Cerro Zapaleri. Mountains in the region include the Cerro Tinte, Zapaleri and other peaks of the Serranía de Dulcenombre. On the eastern shore of the lake lie abandoned tin mining, mines; other resources of partly volcanic origin are basalt and gold and the salt ulexite which was obtained from the Pirquitas mine on the shore of Laguna Vilama. This lake belongs to a group of remote Andean lakes that formed during the Tertiary. These lakes lie at elevations of and are characterized by extreme environmental conditions, including high amounts of Toxic heavy metal, heavy metals such as arsenic, high salinity, high UV radiation, high daily temperature fluctuations and low availability of nutrients. The UV radiation is espe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jujuy Province
Jujuy is a province of Argentina, located in the extreme northwest of the country, at the borders with Chile and Bolivia. The only neighboring Argentine province is Salta to the east and south. Geography There are three main areas in Jujuy: *The Altiplano, a plateau high with peaks of , covers most of the province. *The Río Grande of Jujuy cuts through the Quebrada de Humahuaca canyon, of heights between . *To the southeast, the sierras descends to the Gran Chaco region. The vast difference in height and climate produces desert areas such as the Salinas Grandes salt mines and subtropical Yungas jungle. The terrain of the province is mainly arid and semi-desertic across the different areas, except for the ''El Ramal'' valley of the San Francisco River. Temperature difference between day and night is wider in higher lands, and precipitation is scarce outside the temperate area of the San Francisco River. The Grande River and the San Francisco River flow to the Bermejo River. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Radiation
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. For h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Festuca
''Festuca'' (fescue) is a genus of flowering plants belonging to the grass family Poaceae (subfamily Pooideae). They are evergreen or herbaceous perennial tufted grasses with a height range of and a cosmopolitan distribution, occurring on every continent except Antarctica. The genus is closely related to ryegrass (''Lolium''), and recent evidence from phylogenetic studies using DNA sequencing of plant mitochondrial DNA shows that the genus lacks monophyly. As a result, plant taxonomists have moved several species, including the forage grasses tall fescue and meadow fescue, from the genus ''Festuca'' into the genus ''Lolium'', or alternatively into the segregate genus ''Schedonorus''. Because the taxonomy is complex, scientists have not determined how many true species belong to the genus, but estimates range from more than 400 to over 640.Darbyshire, S. J. and L. E. Pavlick''Festuca''. Grass Manual. Flora of North America. Fescue pollen is a significant contributor to hay feve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wetland
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The primary factor that distinguishes wetlands from terrestrial land forms or Body of water, water bodies is the characteristic vegetation of aquatic plants, adapted to the unique anoxic hydric soils. Wetlands are considered among the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal species. Methods for assessing wetland functions, wetland ecological health, and general wetland condition have been developed for many regions of the world. These methods have contributed to wetland conservation partly by raising public awareness of the functions some wetlands provide. Wetlands occur naturally on every continent. The water in wetlands is either freshwater, brackish or seawater, saltwater. The main w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate (Polypodiidae) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns. Ferns first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramsar Site
A Ramsar site is a wetland site designated to be of international importance under the Ramsar Convention,8 ha (O) *** Permanent 8 ha (P) *** Seasonal Intermittent < 8 ha(Ts) ** es on inorganic soils: *** Permanent (herb dominated) (Tp) *** Permanent / Seasonal / Intermittent (shrub dominated)(W) *** Permanent / Seasonal / Intermittent (tree dominated) (Xf) *** Seasonal/intermittent (herb dominated) (Ts) ** Marshes on soils: *** Permanent (non-forested)(U) *** Permanent (forested)(Xp) ** Marshes on inorganic or peat soils: *** Marshes on inorganic or peat soils / High altitude (alpine) (Va) *** Marshes on inorganic or peat soils / Tundra (Vt) * Saline, |
South American Monsoon
South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþaz'' ("south"), possibly related to the same Proto-Indo-European root that the word ''sun'' derived from. Some languages describe south in the same way, from the fact that it is the direction of the sun at noon (in the Northern Hemisphere), like Latin meridies 'noon, south' (from medius 'middle' + dies 'day', cf English meridional), while others describe south as the right-hand side of the rising sun, like Biblical Hebrew תֵּימָן teiman 'south' from יָמִין yamin 'right', Aramaic תַּימנַא taymna from יָמִין yamin 'right' and Syriac ܬܰܝܡܢܳܐ taymna from ܝܰܡܝܺܢܳܐ yamina (hence the name of Yemen, the land to the south/right of the Levant). Navigation By convention, the ''bottom or down-facing side'' of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circulation through faults to hot rock deep in the Earth's crust. In either case, the ultimate source of the heat is radioactive decay of naturally occurring radioactive elements in the Earth's mantle, the layer beneath the crust. Hot spring water often contains large amounts of dissolved minerals. The chemistry of hot springs ranges from acid sulfate springs with a pH as low as 0.8, to alkaline chloride springs saturated with silica, to bicarbonate springs saturated with carbon dioxide and carbonate minerals. Some springs also contain abundant dissolved iron. The minerals brought to the surface in hot springs often feed communities of extremophiles, microorganisms adapted to extreme conditions, and it is possible that life on Earth had its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Chloride
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g/mol respectively, 100 g of NaCl contains 39.34 g Na and 60.66 g Cl. Sodium chloride is the salt most responsible for the salinity of seawater and of the extracellular fluid of many multicellular organisms. In its edible form, salt (also known as ''table salt'') is commonly used as a condiment and food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further chemical syntheses. Another major application of sodium chloride is de-icing of roadways in sub-freezing weather. Uses In addition to the familiar domestic uses of salt, more dominant applications of the approximately 250 million tonnes per year production (2008 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll
Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum. Hence chlorophyll-containing tissues appear green because green light, diffusively reflected by structures like cell walls, is less absorbed. Two types of chlorophyll exist in the photosystems of green plants: chlorophyll ''a'' and ''b''. History Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. The presence of magnesium in chlorophyll was discovered in 1906, and was that element's first detection in living tissue. After initial work done by German chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vilama (caldera)
Vilama is a Miocene caldera in Bolivia and Argentina. Straddling the border between the two countries, it is part of the Central Volcanic Zone, one of the four volcanic belts in the Andes. Vilama is remote and forms part of the Altiplano-Puna volcanic complex, a province of large calderas and associated ignimbrites that were active since about 8 million years ago, sometimes in the form of supervolcanoes. The Vilama caldera was originally estimated to have a size of but the size was later revised to be between and and is almost entirely buried beneath younger volcanoes that have grown along the margin of the caldera; volcanic activity on these volcanoes continued into the Pleistocene. Several lakes also developed on the floor of the caldera, which contains a resurgent dome. Vilama is the source of the enormous Vilama ignimbrite, which was emplaced during an eruption with a volcanic explosivity index of 8 about 8.4–8.5 million years ago. A large amount of the Vilama ignimbri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puna De Atacama
The Puna de Atacama or Atacama Plateau article at the '''' website is an arid high , in the of northern (15%) and (85%). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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