Patagonia is a sparsely populated region at the southern end of South America, shared by Chile and Argentina. The region comprises the southern section of the Andes mountains and the deserts and grasslands to the east. Patagonia is one of the few regions with coasts on three oceans, with the Pacific Ocean to the west, the Atlantic Ocean to the east, the Southern Ocean to the south; the Colorado and Barrancas rivers, which run from the Andes to the Atlantic, are considered the northern limit of Argentine Patagonia. The archipelago of Tierra del Fuego is sometimes included as part of Patagonia. Most geographers and historians locate the northern limit of Chilean Patagonia at Huincul Fault, in Araucanía Region; the name Patagonia comes from the word patagón, used by Magellan in 1520 to describe the native tribes of the region, whom his expedition thought to be giants. It is now believed that the people he called the Patagons were Tehuelches, who tended to be taller than Europeans of the time; the Argentine researcher Miguel Doura observed that the name Patagonia derives from the ancient Greek region of modern Turkey called Paphlagonia, possible home of the patagon personage in the chivalric romances Primaleon printed in 1512, ten years before Magellan arrived in these southern lands.
The hypothesis was published in a 2011 New Review of Spanish Philology report. Argentine Patagonia is for the most part a region of steppelike plains, rising in a succession of 13 abrupt terraces about 100 metres at a time, covered with an enormous bed of shingle bare of vegetation. In the hollows of the plains are ponds or lakes of fresh and brackish water. Towards Chilean territory the shingle gives place to porphyry and basalt lavas, animal life becomes more abundant and vegetation more luxuriant, consisting principally of southern beech and conifers; the high rainfall against the western Andes and the low sea surface temperatures offshore give rise to cold and humid air masses, contributing to the ice-fields and glaciers, the largest ice-fields in the Southern hemisphere outside of Antarctica. Among the depressions by which the plateau is intersected transversely, the principal ones are the Gualichu, south of the Río Negro, the Maquinchao and Valcheta, the Senguerr, the Deseado River. Besides these transverse depressions, there are others which were occupied by more or less extensive lakes, such as the Yagagtoo and Colhue Huapi, others situated to the south of Puerto Deseado, in the centre of the country.
In the central region volcanic eruptions, which have taken part in the formation of the plateau during the Cenozoic, cover a large part of the land with basaltic lava-caps. There, caused principally by the sudden melting and retreat of ice aided by tectonic changes, has scooped out a deep longitudinal depression, best in evidence where in contact with folded Cretaceous rocks which are uplifted by the Cenozoic granite, it separates the plateau from the first lofty hills, whose ridges are called the pre-Cordillera. To the west of these, a similar longitudinal depression extends all along the foot of the snowy Andean Cordillera; this latter depression contains the richest and most fertile land of Patagonia. Lake basins along the Cordillera were excavated by ice-streams, including Lake Argentino and Lake Fagnano, as well as coastal bays such as Bahía Inútil; the geological limit of Patagonia has been proposed to be Huincul Fault which forms a major discontinuity. The fault truncates various structures including the Pampean orogen found further north.
The ages of base arocks change abruptly across the fault. There have been discrepancies among geologists on the origin of the Patagonian landmass. Víctor Ramos has proposed that the Patagonian landmass originated as an allochthonous terrane that separated from Antarctica and docked in South America 250 to 270 Ma in the Permian era. A 2014 study by R. J. Pankhurst and coworkers rejects any idea of a far-travelled Patagonia claiming it is of parautochtonous origin; the Mesozoic and Cenozoic deposits have revealed a most interesting vertebrate fauna. This, together with the discovery of the perfect cranium of a chelonian of the genus Niolamia, identical with Ninjemys oweni of the Pleistocene age in Queensland, forms an evident proof of the connection between the Australian and South American continents; the Patagonian Niolamia belongs to the Sarmienti Formation. Fossils of the mid-Cretaceous Argentinosaurus, which may be the largest of all dinosaurs, have been found in Patagonia, a model of the mid-Jurassic Piatnitzkysaurus graces the concourse of the Trelew airport.
Of more than paleontological interest, the middle Jurassic Los Molles Formation and the still richer late Jurassic and early Cretaceous Vaca Muerta formation above it in the Neuquén basin are reported to contain huge hydrocarbon reserves accessible through hydraulic fracturing. Other specimens of the interesting fauna of Patagonia, belonging to the Middle Cenozoic, are the gigantic wingless birds, exceeding in size any hitherto known, the singular mammal Pyrotherium of large dimensions. In
Relative humidity is the ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature. Relative humidity depends on the pressure of the system of interest; the same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is that of dewpoint; the relative humidity of an air–water mixture is defined as the ratio of the partial pressure of water vapor in the mixture to the equilibrium vapor pressure of water over a flat surface of pure water at a given temperature: ϕ = p H 2 O p H 2 O ∗. Relative humidity is expressed as a percentage. At 100 % relative humidity, the air is at its dewpoint. Climate control refers to the control of temperature and relative humidity in buildings and other enclosed spaces for the purpose of providing for human comfort and safety, of meeting environmental requirements of machines, sensitive materials and technical processes. Along with air temperature, mean radiant temperature, air speed, metabolic rate, clothing level, relative humidity plays a role in human thermal comfort.
According to ASHRAE Standard 55-2017: Thermal Environmental Conditions for Human Occupancy, indoor thermal comfort can be achieved through the PMV method with relative humidities ranging from 0% to 100%, depending on the levels of the other factors contributing to thermal comfort. However, the recommended range of indoor relative humidity in air conditioned buildings is 30-60%. In general, higher temperatures will require lower relative humidities to achieve thermal comfort compared to lower temperatures, with all other factors held constant. For example, with clothing level = 1, Metabolic rate = 1.1, air speed 0.1 m/s, a change in air temperature and mean radiant temperature from 20 degrees C to 24 degrees C would lower the maximum acceptable relative humidity from 100% to 65% to maintain thermal comfort conditions. The CBE Thermal Comfort Tool can be used to demonstrate the effect of relative humidity for specific thermal comfort conditions and it can be used to demonstrate compliance with ASHRAE Standard 55-2017.
When using the adaptive model to predict thermal comfort indoors, relative humidity is not taken into account. Although relative humidity is an important factor for thermal comfort, humans are more sensitive to variations in temperature than they are to changes in relative humidity. Relative humidity has a small effect on thermal comfort outdoors when air temperatures are low, a more pronounced effect at moderate air temperatures, a much stronger influence at higher air temperatures. In cold climates, the outdoor temperature causes lower capacity for water vapor to flow about, thus although it may be snowing and the relative humidity outdoors is high, once that air comes into a building and heats up, its new relative humidity is low, making the air dry, which can cause discomfort. Dry cracked. Low humidity causes tissue lining nasal passages to dry and become more susceptible to penetration of Rhinovirus cold viruses. Low humidity is a common cause of nosebleeds; the use of a humidifier in homes bedrooms, can help with these symptoms.
Indoor relative humidities should be kept above 30% to reduce the likelihood of the occupant's nasal passages drying out. Humans can be comfortable within a wide range of humidities depending on the temperature—from 30% to 70%—but ideally between 50% and 60%. Low humidity can create discomfort, respiratory problems, aggravate allergies in some individuals. In the winter, it is advisable to maintain relative humidity above. Low relative humidities may cause eye irritation. For climate control in buildings using HVAC systems, the key is to maintain the relative humidity at a comfortable range—low enough to be comfortable but high enough to avoid problems associated with dry air; when the temperature is high and the relative humidity is low, evaporation of water is rapid. Wooden furniture can shrink; when the temperature is low and the relative humidity is high, evaporation of water is slow. When relative humidity approaches 100 percent, condensation can occur on surfaces, leading to problems with mold, corrosion and other moisture-related deterioration.
Condensation can pose a safety risk as it can promote the growth of mold and wood rot as well as freezing emergency exits shut. Certain production and technical processes and treatments in factories, laboratories and other facilities require specific relative humidity levels to be maintained using humidifiers and associated control systems; the basic principles for buildings, above apply to vehicles. In addition, there may be safety considerations. For instance, high humidity inside a vehicle can lead to problems of condensation, such
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, sleet, snow and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and "precipitates", thus and mist are not precipitation but suspensions, because the water vapor does not condense sufficiently to precipitate. Two processes acting together, can lead to air becoming saturated: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called "showers."Moisture, lifted or otherwise forced to rise over a layer of sub-freezing air at the surface may be condensed into clouds and rain. This process is active when freezing rain occurs. A stationary front is present near the area of freezing rain and serves as the foci for forcing and rising air.
Provided necessary and sufficient atmospheric moisture content, the moisture within the rising air will condense into clouds, namely stratus and cumulonimbus. The cloud droplets will grow large enough to form raindrops and descend toward the Earth where they will freeze on contact with exposed objects. Where warm water bodies are present, for example due to water evaporation from lakes, lake-effect snowfall becomes a concern downwind of the warm lakes within the cold cyclonic flow around the backside of extratropical cyclones. Lake-effect snowfall can be locally heavy. Thundersnow is possible within lake effect precipitation bands. In mountainous areas, heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation. On the leeward side of mountains, desert climates can exist due to the dry air caused by compressional heating. Most precipitation is caused by convection; the movement of the monsoon trough, or intertropical convergence zone, brings rainy seasons to savannah climes.
Precipitation is a major component of the water cycle, is responsible for depositing the fresh water on the planet. 505,000 cubic kilometres of water falls as precipitation each year. Given the Earth's surface area, that means the globally averaged annual precipitation is 990 millimetres, but over land it is only 715 millimetres. Climate classification systems such as the Köppen climate classification system use average annual rainfall to help differentiate between differing climate regimes. Precipitation may occur on other celestial bodies, e.g. when it gets cold, Mars has precipitation which most takes the form of frost, rather than rain or snow. Precipitation is a major component of the water cycle, is responsible for depositing most of the fresh water on the planet. 505,000 km3 of water falls as precipitation each year, 398,000 km3 of it over the oceans. Given the Earth's surface area, that means the globally averaged annual precipitation is 990 millimetres. Mechanisms of producing precipitation include convective and orographic rainfall.
Convective processes involve strong vertical motions that can cause the overturning of the atmosphere in that location within an hour and cause heavy precipitation, while stratiform processes involve weaker upward motions and less intense precipitation. Precipitation can be divided into three categories, based on whether it falls as liquid water, liquid water that freezes on contact with the surface, or ice. Mixtures of different types of precipitation, including types in different categories, can fall simultaneously. Liquid forms of precipitation include drizzle. Rain or drizzle that freezes on contact within a subfreezing air mass is called "freezing rain" or "freezing drizzle". Frozen forms of precipitation include snow, ice needles, ice pellets and graupel; the dew point is the temperature to which a parcel must be cooled in order to become saturated, condenses to water. Water vapor begins to condense on condensation nuclei such as dust and salt in order to form clouds. An elevated portion of a frontal zone forces broad areas of lift, which form clouds decks such as altostratus or cirrostratus.
Stratus is a stable cloud deck which tends to form when a cool, stable air mass is trapped underneath a warm air mass. It can form due to the lifting of advection fog during breezy conditions. There are four main mechanisms for cooling the air to its dew point: adiabatic cooling, conductive cooling, radiational cooling, evaporative cooling. Adiabatic cooling occurs when air expands; the air can rise due to convection, large-scale atmospheric motions, or a physical barrier such as a mountain. Conductive cooling occurs when the air comes into contact with a colder surface by being blown from one surface to another, for example from a liquid water surface to colder land. Radiational cooling occurs due to the emission of infrared radiation, either by the air or by the surface underneath. Evaporative cooling occurs when moisture is added to the air through evaporation, which forces the air temperature to cool to its wet-bulb temperature, or until it reaches saturation; the main ways water vapor is added to the air are: wind convergence into areas of upward motion, precipitation or virga falling from above, daytime heating evaporating water from the surface of oceans, water bodies or wet lan
Snowcat service in Colorado, USA]] A ski lift is a mechanism for transporting skiers up a hill. Ski lifts are a paid service at ski resorts; the first ski lift was built in 1908 by German Robert Winnerbalder in Schollach/Eisenbach, Hochschwarzwald. Aerial lifts transport skiers. Aerial lifts are bicable ropeways, the "bi-" prefix meaning that the cables have two different functions. Aerial tramways Chairlifts and detachable chairlifts Funifors Funitels Gondola lifts Hybrid lifts Surface lifts, including T-bars, magic carpets, rope tows. Cable railways, including funiculars Helicopters are used for heliskiing and snowcats for snowcat skiing; this is backcountry skiing or boarding accessed by a snowcat or helicopter instead of a lift, or by hiking. Cat skiing is less than half the cost of heliskiing, more expensive than a lift ticket but is easier than ski touring. Cat skiing is guided. Skiing at select, extreme resorts, like Silverton Mountain, is guided when skiing just off the lift. Ski lift are built on both southern hemisphere.
Extreme locations of non indoor ski lifts: The most northern is near Tromsø, Norway The most southern is near Ushuaia, Argentina The closest to equator from north is near Liang, China The closest to equator from south is near Mahlasela, Lesotho
A mountain is a large landform that rises above the surrounding land in a limited area in the form of a peak. A mountain is steeper than a hill. Mountains are formed through tectonic forces or volcanism; these forces can locally raise the surface of the earth. Mountains erode through the action of rivers, weather conditions, glaciers. A few mountains are isolated summits. High elevations on mountains produce colder climates than at sea level; these colder climates affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains tend to be used less for agriculture and more for resource extraction and recreation, such as mountain climbing; the highest mountain on Earth is Mount Everest in the Himalayas of Asia, whose summit is 8,850 m above mean sea level. The highest known mountain on any planet in the Solar System is Olympus Mons on Mars at 21,171 m. There is no universally accepted definition of a mountain.
Elevation, relief, steepness and continuity have been used as criteria for defining a mountain. In the Oxford English Dictionary a mountain is defined as "a natural elevation of the earth surface rising more or less abruptly from the surrounding level and attaining an altitude which to the adjacent elevation, is impressive or notable."Whether a landform is called a mountain may depend on local usage. Mount Scott outside Lawton, Oklahoma, USA, is only 251 m from its base to its highest point. Whittow's Dictionary of Physical Geography states "Some authorities regard eminences above 600 metres as mountains, those below being referred to as hills." In the United Kingdom and the Republic of Ireland, a mountain is defined as any summit at least 2,000 feet high, whilst the official UK government's definition of a mountain, for the purposes of access, is a summit of 600 metres or higher. In addition, some definitions include a topographical prominence requirement 100 or 500 feet. At one time the U.
S. Board on Geographic Names defined a mountain as being 1,000 feet or taller, but has abandoned the definition since the 1970s. Any similar landform lower. However, the United States Geological Survey concludes that these terms do not have technical definitions in the US; the UN Environmental Programme's definition of "mountainous environment" includes any of the following: Elevation of at least 2,500 m. Using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, 14% of Africa; as a whole, 24% of the Earth's land mass is mountainous. There are three main types of mountains: volcanic and block. All three types are formed from plate tectonics: when portions of the Earth's crust move and dive. Compressional forces, isostatic uplift and intrusion of igneous matter forces surface rock upward, creating a landform higher than the surrounding features; the height of the feature makes it either a hill or, if steeper, a mountain. Major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity.
Volcanoes are formed when a plate is pushed at a mid-ocean ridge or hotspot. At a depth of around 100 km, melting occurs in rock above the slab, forms magma that reaches the surface; when the magma reaches the surface, it builds a volcanic mountain, such as a shield volcano or a stratovolcano. Examples of volcanoes include Mount Pinatubo in the Philippines; the magma does not have to reach the surface in order to create a mountain: magma that solidifies below ground can still form dome mountains, such as Navajo Mountain in the US. Fold mountains occur when two plates collide: shortening occurs along thrust faults and the crust is overthickened. Since the less dense continental crust "floats" on the denser mantle rocks beneath, the weight of any crustal material forced upward to form hills, plateaus or mountains must be balanced by the buoyancy force of a much greater volume forced downward into the mantle, thus the continental crust is much thicker under mountains, compared to lower lying areas.
Rock can fold either asymmetrically. The upfolds are anticlines and the downfolds are synclines: in asymmetric folding there may be recumbent and overturned folds; the Balkan Mountains and the Jura Mountains are examples of fold mountains. Block mountains are caused by faults in the crust: a plane; when rocks on one side of a fault rise relative to the other, it can form a mountain. The uplifted blocks are block horsts; the intervening dropped blocks are termed graben: these can be small or form extensive rift valley systems. This form of landscape can be seen in East Africa, the Vosges, the Basin and Range Province of Western North America and the Rhine valley; these areas occur when the regional stress is extensional and the crust is thinned. During and following uplift, mountains are subjected to the agents of erosion which wear the uplifted area down. Erosion causes the surface of mountains to be younger than the rocks that form the mountains themselves. Glacial processes produce characteristic landforms, such as pyramidal peaks, knife-edge arêtes, bowl-shaped cirques that can contai
A ski is a narrow strip of semi-rigid material worn underfoot to glide over snow. Longer than wide and characteristically employed in pairs, skis are attached to ski boots with ski bindings, with either a free, lockable, or secured heel. For climbing slopes, ski skins can be attached at the base of the ski. Intended as an aid to travel over snow, they are now used recreationally in the sport of skiing; the word ski comes from the Old Norse word skíð which means "cleft wood", "stick of wood" or "ski". In Old Norse common phrases describing skiing were fara á renna and skríða á skíðum. In modern Norwegian the word ski has retained the Old Norse meaning in words for split firewood, wood building materials and roundpole fence. In Norwegian this word is pronounced. In Swedish, another language evolved from Old Norse, the word is skidor. English and French use the original Norwegian spelling ski, modify the pronunciation. Prior to 1920, English usage of skee and snow-shoe was seen. In Italian, it is pronounced to Norwegian, but the spelling is modified accordingly: sci.
Portuguese and Spanish adapt the word to their linguistic rules: esqui and esquí. In German, spellings Ski and Schi are in use. In Dutch, the word is ski and the pronunciation was as in Norwegian, but since the 1960s changed to. In Welsh the word is spelled sgi. Many languages make a verb form out of the noun, such as to ski in English, skier in French, esquiar in Spanish and Portuguese, sciare in Italian, skiën in Dutch, or Schi laufen or Schi fahren in German. Norwegian and Swedish do not form a verb from the noun. Finnish has its own ancient words for skis and skiing: "ski" is suksi and "skiing" is hiihtää; the word suksi goes back to the Proto-Uralic period, with cognates such as Erzya soks, Mansi tåut and Nganasan tuta. The Sami have their own words for "skis" and "skiing": for example, the Lule Sami word for "ski" is sabek and skis are called sabega; the Sami use cuoigat for the verb "to ski". The oldest wooden skis found were in Russia and Norway respectively. Nordic ski technology was adapted during the early 20th century to enable skiers to turn at higher speeds.
New ski and ski binding designs, coupled with the introduction of ski lifts to carry skiers up slopes, enabled the development of alpine skis. Meanwhile, advances in technology in the Nordic camp allowed for the development of special skis for skating and ski jumping; this type of ski was used at least in northern Sweden until the 1930s. On one leg, the skier wore a long straight non-arching ski for sliding, on the other a shorter ski for kicking; the bottom of the short ski was either plain or covered with animal skin to aid this use, while the long ski supporting the weight of the skier was treated with animal fat in similar manner to modern ski waxing. Early record of this type of skis survives in works of Olaus Magnus, he associates them to Sami people and gives Sami names of savek and golos for the plain and skinned short ski. Finnish names for these are kalhu for long and short ski; the seal hunters at the Gulf of Bothnia had developed a special long ski to sneak into shooting distance to the seals' breathing holes, though the ski was useful in moving in the packed ice in general and was made specially long, 3–4 meters, to protect against cracks in the ice.
This is called skredstång in Swedish. Around 1850, artisans in Telemark, invented the cambered ski; this ski arches up in the middle, under the binding, which distributes the skier's weight more evenly across the length of the ski. Earlier plank-style skis had to be thick enough not to bow downward and sink in the snow under the skier’s weight; this new design made it possible to build a thinner, lighter ski, that flexed more to absorb the shock of bumps, that maneuvered and ran faster and more easily. The design included a sidecut that narrowed the ski underfoot while the tip and tail remained wider; this enabled the ski to turn more easily. Skis traditionally were hand-carved out of a single piece of hardwood such as Birch or Ash; these woods were used because of their density and ability to handle speed and shock-resistance factors associated with ski racing. Because of Europe’s dwindling forests, the ability to find quality plank hardwood became difficult, which led to the invention of the laminated ski.
Beginning in 1891, skimakers in Norway began laminating two or more layers of wood together to make lighter cross country running skis. These evolved into the multi-laminated high-performance skis of the mid-1930s. A laminated ski is a ski composed of two different types of wood. A top layer of soft wood is glued to a thin layer under a surface of hardwood; this combination created skis which were much lighter and more maneuverable than the heavy, hardwood skis that preceded them. Although lighter and stronger, laminated skis did not wear well; the water-soluble glues used at the time failed. In 1922, a Norwegian skier, Thorbjorn Nordby, developed strong, waterproof glue which stopped the problem of splitting, therefore developing a much tougher laminated ski. Research and design of laminated skis progressed. In 1933, a new design technology was introduced involving an outer hardwood shell completely
Chapelco, or Cerro Chapelco, is a mountain and massif in Neuquén Province, south-western Argentina. The ski station of the same name is located 19 kilometres from the resort town of San Martín de los Andes. Designed by Federico Graeff and established in 1946, Chapelco became an popular tourist destination after 1970; the station maintains a ski and snowboard school with 200 instructors for all ages as well as numerous lodges, the most important of, the Graeff Lodge. The station is accessible via National Route 234 from San Martín de los Andes, via a two-hour flight from Jorge Newbery Airport in Buenos Aires to the Aviador Carlos Campos Airport. Chapelco hosted Snowboardcross events for the 2008-09 and 2009-10 FIS Snowboard World Cup: Cerro Catedral Cerro Castor Las Leñas List of ski areas and resorts in South America South American Ski Resort Vacation Comparison Tool Chapelco Ski Vacation Packages and Tours