Chullo is an Andean style of hat with earflaps, made from vicuña, llama or sheeps wool. Alpaca has wool-like qualities that help to insulate its wearer from the elements in the Andean Mountain region. Chullos often have ear-flaps that can be tied under the chin, chullos have been used in the Andean Mountain region by indigenous peoples for thousands of years. Wearing different types and colors has a significance among the Andean natives, Andean culture Ushanka, a Russian hat of similar design
The subarctic climate is a climate characterised by long, usually very cold winters, and short, cool to mild summers. It is found on large landmasses, away from the effects of an ocean. These climates represent Köppen climate classification Dfc, Dsc, Dfd and Dsd. This type of climate offers some of the most extreme seasonal temperature variations found on the planet, in winter, temperatures can drop to −40 °C and in summer, record low temperatures can be as cold as −60 °C. With 5–7 consecutive months where the temperature is below freezing. Summer warmth is insufficient to thaw more than a few surface feet, seasonal thaw penetrates from 2 to 14 ft, depending on latitude and type of ground. Some northern areas with subarctic climates located near oceans, have milder winters and no permafrost, the frost-free season is very short, varying from about 45 to 100 days at most, and a freeze can occur during any month in many areas. Most subarctic climates have very little precipitation, typically no more than 380 mm over an entire year, a notable exception to this pattern is that subarctic climates occurring at high altitudes in otherwise temperate regions have extremely high precipitation due to orographic lift.
Mount Washington, with temperatures typical of a climate, receives an average rain-equivalent of 101.91 inches of precipitation per year.5 metres that does not melt until June. Vegetation in regions with subarctic climates is generally of low diversity, as only hardy species can survive the long winters, trees are mostly limited to conifers, as few broadleaved trees are able to survive the very low temperatures in winter. This type of forest is known as taiga, a term which is sometimes applied to the climate found therein as well. Even though the diversity may be low, numbers are high, the process by which plants become acclimated to cold temperatures is called hardening. In some areas, ice has scoured rock surfaces bare, entirely stripping off the overburden, elsewhere rock basins have been formed and stream courses dammed, creating countless lakes. The Tatra Mountains in Poland, above 800m, the Eastern Anatolia, between 1,600 and 2,100 meters – Turkey. The Pyrenees, between 1,600 and 2,100 meters – Andorra and Spain, further north in Siberia, continentality increases so much that winters can be exceptionally severe, averaging below −38 °C, even though the hottest month still averages more than 10 °C.
This creates Dfd and Dsd climates, one example is parts of the Snowy Mountains in Australia, although theyre more alpine than true subarctic. In China and Mongolia, as one moves southwestwards or towards lower altitudes, temperatures increase, Boreal ecology Boreal forest Plants of continental subarctic climate Köppen climate classification Subantarctic
Bratschen are weathering products that occur as a result of frost and aeolian corrasion almost exclusively on the calc-schists of the Upper Slate Mantle in the High Tauern mountains of Austria. The term is German but is used untranslated in English sources and it may be the equivalent of the New Zealand climbers term weet-bix for a rock that disintegrates easily and so is difficult to climb on. The calc-schist, that appears blue-gray when freshly broken, weathers to a yellow to brown colour and these form steep, almost unvegetated mountainsides with an odd and rough-textured surface, caused by wind erosion. Bratschen are found on the such as the Fuscherkarkopf, the Großer Bärenkopf, the Kitzsteinhorn. Karl Krainer, Nationalpark Hohe Tauern GEOLOGIE – Wissenschaftliche Schriften, Universitätsverlag Carinthia, pp.140, ISBN 3-85378-585-9
Weathering is the breaking down of rocks and minerals as well as wood and artificial materials through contact with the Earths atmosphere and biological organisms. Two important classifications of weathering processes exist – physical and chemical weathering, mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric conditions, such as heat, water and pressure. While physical weathering is accentuated in very cold or very dry environments, chemical reactions are most intense where the climate is wet, both types of weathering occur together, and each tends to accelerate the other. For example, physical abrasion decreases the size of particles and therefore increases their surface area, the various agents act in concert to convert primary minerals to secondary minerals and release plant nutrient elements in soluble forms. The materials left over after the rock breaks down combined with organic material creates soil, in addition, many of Earths landforms and landscapes are the result of weathering processes combined with erosion and re-deposition.
Physical weathering, recognized as mechanical weathering, is the class of processes that causes the disintegration of rocks without chemical change, the primary process in physical weathering is abrasion. However and physical weathering often go hand in hand, physical weathering can occur due to temperature, frost etc. For example, cracks exploited by physical weathering will increase the area exposed to chemical action. Abrasion by water and wind loaded with sediment can have tremendous cutting power, as is amply demonstrated by the gorges, ravines. In glacial areas, huge moving ice masses embedded with soil and rock fragments grind down rocks in their path, plant roots sometimes enter cracks in rocks and pry them apart, resulting in some disintegration, Burrowing animals may help disintegrate rock through their physical action. However, such influences are usually of importance in producing parent material when compared to the drastic physical effects of water, wind. Physical weathering is called mechanical weathering or disaggregation.
Thermal stress weathering results from the expansion and contraction of rock, for example, heating of rocks by sunlight or fires can cause expansion of their constituent minerals. As some minerals expand more than others, temperature changes set up differential stresses that cause the rock to crack apart. Because the outer surface of a rock is often warmer or colder than the more protected inner portions and this process may be sharply accelerated if ice forms in the surface cracks. When water freezes, it expands with a force of about 1465 Mg/m^2, disintegrating huge rock masses, thermal stress weathering comprises two main types, thermal shock and thermal fatigue. Thermal stress weathering is an important mechanism in deserts, where there is a diurnal temperature range, hot in the day. The repeated heating and cooling exerts stress on the layers of rocks
In geology, a boulder is a rock fragment with size greater than 25.6 centimetres in diameter. Smaller pieces are called cobbles and pebbles, while a boulder may be small enough to move or roll manually, others are extremely massive. In common usage, a boulder is too large for a person to move, smaller boulders are usually just called rocks or stones. The word boulder is short for boulder stone, from Middle English bulderston or Swedish bullersten, in places covered by ice sheets during Ice Ages, such as Scandinavia, northern North America, and Siberia, glacial erratics are common. Erratics are boulders picked up by ice sheets during their advance and they are called erratic because they typically are of a different rock type than the bedrock on which they are deposited. One of them is used as the pedestal of the Bronze Horseman in Saint Petersburg, boulder sized clasts are found in some sedimentary rocks, such as coarse conglomerate and boulder clay. The climbing of large boulders is called bouldering, road debris Monolith Media related to Boulders at Wikimedia Commons
The polar climate regions are characterized by a lack of warm summers. Every month in a polar climate has a temperature of less than 10 °C. Regions with polar climate cover more than 20% of the Earth, the sun shines for long hours in the summer, and for many fewer hours in the winter. A polar climate results in treeless tundra, glaciers, or a permanent or semi-permanent layer of ice and it has cool summers and very cold winters. There are two types of climate, ET, or tundra climate, and EF, or ice cap climate. A tundra climate is characterized by having at least one month whose average temperature is above 0 °C, in a tundra climate, trees cannot grow, but other specialized plants can grow. In an ice cap climate, no plants can grow, many high altitude locations on Earth have a climate where no month has an average temperature of 10 °C or higher, but as this is due to elevation, this climate is referred to as Alpine climate. Alpine climate can mimic either tundra or ice cap climate, on Earth, the only continent where the ice cap polar climate is predominant is Antarctica.
All but a few isolated areas on the island of Greenland have the ice cap climate. Coastal regions of Greenland that do not have permanent ice sheets have the less extreme tundra climates, large areas in northern Canada and northern Alaska have tundra climate, changing to ice cap climate in the most northern parts of Canada. These subantarctic lowlands are found closer to the equator than the coastal tundras of the Arctic basin, some parts of the Arctic are covered by ice year-round, and nearly all parts of the Arctic experience long periods with some form of ice on the surface. Average January temperatures range from about −40 to 0 °C, average July temperatures range from about −10 to 10 °C, with some land areas occasionally exceeding 30 °C in summer. The Arctic consists of ocean that is surrounded by land. As such, the climate of much of the Arctic is moderated by the ocean water, in summer, the presence of the nearby water keeps coastal areas from warming as much as they might otherwise, just as it does in temperate regions with maritime climates.
The climate of Antarctica is the coldest on the whole of Earth, Antarctica has the lowest temperature ever recorded, −89.2 °C at Vostok Station. It is dry, averaging 166 millimetres of precipitation per year. Even so, on most parts of the continent the snow melts and is eventually compressed to become the glacial ice that makes up the ice sheet. Weather fronts rarely penetrate far into the continent, there have been several attempts at quantifying what constitutes a polar climate
Science, widely referred to as Science Magazine, is the peer-reviewed academic journal of the American Association for the Advancement of Science and one of the worlds top academic journals. It was first published in 1880, is circulated weekly and has a print subscriber base of around 130,000. Because institutional subscriptions and online access serve an audience, its estimated readership is 570,400 people. Unlike most scientific journals, which focus on a field, Science. According to the Journal Citation Reports, Sciences 2015 impact factor was 34.661, although it is the journal of the AAAS, membership in the AAAS is not required to publish in Science. Papers are accepted from authors around the world, competition to publish in Science is very intense, as an article published in such a highly cited journal can lead to attention and career advancement for the authors. Fewer than 7% of articles submitted are accepted for publication, Science is based in Washington, D. C. United States, with an office in Cambridge, England.
Science was founded by New York journalist John Michels in 1880 with financial support from Thomas Edison, the journal never gained enough subscribers to succeed and ended publication in March 1882. Entomologist Samuel H. Scudder resurrected the journal one year and had some success while covering the meetings of prominent American scientific societies, however, by 1894, Science was again in financial difficulty and was sold to psychologist James McKeen Cattell for $500. In an agreement worked out by Cattell and AAAS secretary Leland O. Howard, after Cattell died in 1944, the ownership of the journal was transferred to the AAAS. After Cattells death in 1944, the journal lacked a consistent editorial presence until Graham DuShane became editor in 1956. In 1958, under DuShanes leadership, Science absorbed The Scientific Monthly, physicist Philip Abelson, a co-discoverer of neptunium, served as editor from 1962 to 1984. Under Abelson the efficiency of the process was improved and the publication practices were brought up to date.
During this time, papers on the Apollo program missions and some of the earliest reports on AIDS were published, biochemist Daniel E. Koshland, Jr. served as editor from 1985 until 1995. From 1995 until 2000, neuroscientist Floyd E. Bloom held that position, biologist Donald Kennedy became the editor of Science in 2000. Biochemist Bruce Alberts took his place in March 2008, geophysicist Marcia McNutt became editor-in-chief in June 2013. During her tenure the family of journals expanded to include Science Robotics and Science Immunology, jeremy M. Berg became editor-in-chief on July 1,2016
Ice growth requires a water supply that delivers water to the freezing front via capillary action in certain soils. The weight of overlying soil restrains vertical growth of the ice, yet the force of one or more growing ice lenses is sufficient to lift a layer of soil, as much as 1 foot or more. The soil through which passes to feed the formation of ice lenses must be sufficiently porous to allow capillary action. Such soil is referred to as frost susceptible, the growth of ice lenses continually consumes the rising water at the freezing front. Differential frost heaving can crack road surfaces—contributing to springtime pothole formation—and damage building foundations, according to Beskow, Urban Hjärne described frost effects in soil in 1694. e. With little contribution from migration of water within the soil, Ice is unusual among compounds because it increases in molar volume from its liquid state, water. Most compounds decrease in volume when changing phase from liquid to solid, taber showed that the vertical displacement of soil in frost heaving can be significantly greater than that due to molar volume expansion.
Taber demonstrated that liquid water migrates towards the line within soil. He showed that other liquids, such as benzene, which contracts when it freezes and this excluded molar volume changes as the dominant mechanism for vertical displacement of freezing soil. His experiments further demonstrated the development of ice lenses inside columns of soil that were frozen by cooling the surface only. The dominant cause of displacement in frost heaving is the development of ice lenses. During frost heave, one or more soil-free ice lenses grow and these lenses grow by the continual addition of water from a groundwater source that is lower in the soil and below the freezing line in the soil. The presence of soil with a pore structure that allows capillary flow is essential to supplying water to the ice lenses as they form. Owing to the Gibbs–Thomson effect of the confinement of liquids in pores and this effect allows water to percolate through the soil towards the ice lens, allowing the lens to grow.
Another water-transport effect is the preservation of a few layers of liquid water on the surface of the ice lens. Faraday reported in 1860 on the layer of premelted water. Ice premelts against its own vapor, and in contact with silica, the same intermolecular forces that cause premelting at surfaces contribute to frost heaving at the particle scale on the bottom side of the forming ice lens. The thickness of such a film is temperature dependent and is thinner on the side of the particle
Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. It occurs because of forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, the combination of surface tension, the first recorded observation of capillary action was by Leonardo da Vinci. A former student of Galileo, Niccolò Aggiunti, was said to have investigated capillary action, boyle reported an experiment in which he dipped a capillary tube into red wine and subjected the tube to a partial vacuum. Some thought that liquids rose in capillaries because air couldnt enter capillaries as easily as liquids, others thought that the particles of liquid were attracted to each other and to the walls of the capillary. They derived the Young–Laplace equation of capillary action, by 1830, the German mathematician Carl Friedrich Gauss had determined the boundary conditions governing capillary action.
In 1871, the British physicist William Thomson determined the effect of the meniscus on a liquids vapor pressure—a relation known as the Kelvin equation, German physicist Franz Ernst Neumann subsequently determined the interaction between two immiscible liquids. Albert Einsteins first paper, which was submitted to Annalen der Physik in 1900, was on capillarity, a common apparatus used to demonstrate the first phenomenon is the capillary tube. When the lower end of a glass tube is placed in a liquid, such as water. Adhesion occurs between the fluid and the inner wall pulling the liquid column up until there is a sufficient mass of liquid for gravitational forces to overcome these intermolecular forces. So, a tube will draw a liquid column higher than a wider tube will. Capillary action is essential for the drainage of constantly produced tear fluid from the eye, wicking is the absorption of a liquid by a material in the manner of a candle wick. Paper towels absorb liquid through capillary action, allowing a fluid to be transferred from a surface to the towel, the small pores of a sponge act as small capillaries, causing it to absorb a large amount of fluid.
Some textile fabrics are said to use capillary action to wick sweat away from the skin and these are often referred to as wicking fabrics, after the capillary properties of candle and lamp wicks. Capillary action is observed in thin layer chromatography, in which a solvent moves vertically up a plate via capillary action, in this case the pores are gaps between very small particles. Capillary action draws ink to the tips of fountain pen nibs from a reservoir or cartridge inside the pen, in hydrology, capillary action describes the attraction of water molecules to soil particles. Capillary action is responsible for moving groundwater from wet areas of the soil to dry areas, differences in soil potential drive capillary action in soil. Thus the thinner the space in which the water can travel, for a water-filled glass tube in air at standard laboratory conditions, γ =0.0728 N/m at 20 °C, ρ =1000 kg/m3, and g =9.81 m/s2
The pascal is the SI derived unit of pressure used to quantify internal pressure, Youngs modulus and ultimate tensile strength. It is defined as one newton per square meter and it is named after the French polymath Blaise Pascal. Common multiple units of the pascal are the hectopascal which is equal to one millibar, the unit of measurement called standard atmosphere is defined as 101,325 Pa and approximates to the average pressure at sea-level at the latitude 45° N. Meteorological reports typically state atmospheric pressure in hectopascals, the unit is named after Blaise Pascal, noted for his contributions to hydrodynamics and hydrostatics, and experiments with a barometer. The name pascal was adopted for the SI unit newton per square metre by the 14th General Conference on Weights, one pascal is the pressure exerted by a force of magnitude one newton perpendicularly upon an area of one square metre. The unit of measurement called atmosphere or standard atmosphere is 101325 Pa and this value is often used as a reference pressure and specified as such in some national and international standards, such as ISO2787, ISO2533 and ISO5024.
In contrast, IUPAC recommends the use of 100 kPa as a standard pressure when reporting the properties of substances, geophysicists use the gigapascal in measuring or calculating tectonic stresses and pressures within the Earth. Medical elastography measures tissue stiffness non-invasively with ultrasound or magnetic resonance imaging, in materials science and engineering, the pascal measures the stiffness, tensile strength and compressive strength of materials. In engineering use, because the pascal represents a small quantity. The pascal is equivalent to the SI unit of energy density and this applies not only to the thermodynamics of pressurised gases, but to the energy density of electric and gravitational fields. In measurements of sound pressure, or loudness of sound, one pascal is equal to 94 decibels SPL, the quietest sound a human can hear, known as the threshold of hearing, is 0 dB SPL, or 20 µPa. The airtightness of buildings is measured at 50 Pa, the units of atmospheric pressure commonly used in meteorology were formerly the bar, which was close to the average air pressure on Earth, and the millibar.
Since the introduction of SI units, meteorologists generally measure pressures in hectopascals unit, exceptions include Canada and Portugal, which use kilopascals. In many other fields of science, the SI is preferred, many countries use the millibar or hectopascal to give aviation altimeter settings. In practically all fields, the kilopascal is used instead. Centimetre of water Metric prefix Orders of magnitude Pascals law
Alpine climate is the average weather for the regions above the tree line. This climate is referred to as a mountain climate or highland climate. There are multiple definitions of alpine climate, one simple definition is the climate which causes trees to fail to grow due to cold. According to the Holdridge life zone system, alpine climate occurs when the mean biotemperature of a location is between 1.5 and 3 °C, which prevents tree growth. Biotemperature is defined as the temperature, except all temperatures below 0 °C are treated as 0 °C, in the Köppen climate classification, the alpine climate is part of Group E, along with the polar climate, where no month has a mean temperature higher than 10 °C. The temperature profile of the atmosphere is a result of an interaction between radiation and convection, sunlight in the visible spectrum hits the ground and heats it. The ground heats the air at the surface, when air is hot, it tends to expand, which lowers its density. Thus, hot air tends to rise and transfer heat upward and this is the process of convection.
Convection comes to equilibrium when a parcel at air at a given altitude has the density as its surroundings. Air is a conductor of heat, so a parcel of air will rise. This is known as a process, which has a characteristic pressure-temperature curve. As the pressure gets lower, the temperature decreases, the rate of decrease of temperature with elevation is known as the adiabatic lapse rate, which is approximately 9.8 °C per kilometre of altitude. Note that the presence of water in the atmosphere complicates the process of convection, water vapor contains latent heat of vaporization. As air rises and cools, it becomes saturated and cannot hold its quantity of water vapor. The water vapor condenses, and releases heat, which changes the rate from the dry adiabatic lapse rate to the moist adiabatic lapse rate. The actual lapse rate, called the lapse rate, is not constant. Therefore, moving up 100 metres on a mountain is roughly equivalent to moving 80 kilometres towards the pole and this relationship is only approximate, since local factors, such as proximity to oceans, can drastically modify the climate.
As the altitude increases, the form of precipitation becomes snow
In geomorphology, solifluction is a gradual mass wasting slope process related to freeze-thaw activity, occurring in periglacial environments. In 1906 Johan Gunnar Andersson interpreted solifluction as a mass wasting process that occurs most commonly in colder climates where periods of freezing and thawing are regular occurrences. A type of process, solifluction describes the slow downslope movement of water-saturated sediment due to recurrent freezing and thawing of the ground. Frost heave due to ice expansion and gelifluction during thaw settlement of the ground, cause gravity-induced shear deformation of sediment. The rates of movement are highly dependent on active layer thaw depths, ice content. Solifluction rates vary dependent on season and can range from centimeters per week to centimeters per year, Solifluction landforms, such as solifluction lobes or sheets, occur over large shallow sloping areas and are one of the most widespread periglacial landforms. Lobes, on average, can be 30–50 m wide, Solifluction lobes move most quickly in the center of the mass, and slower around the edges causing larger amounts of sediment to accumulate around the edges.
When many lobes are in sequence, the appearance is like a staircase in profile, over-saturation is caused when an abundant amount of fluid is formed during thaw and cannot filter through the frozen ground underneath. The saturated material begins to flow, having the consistency of wet concrete, landscapes that have been a product of solifluction have been described as having the consistency of thick porridge. Solifluction is a form of ice-mediated creep, in temperate and tundra region, soil flows occur when the surface layers of frozen ground thaw in spring. Soil and rock debris lubricated by the melt-water flow easily over the underlying frozen subsoil, in areas of peat soils, the peat absorbs much moisture. However, if saturation point is reached the peaty soil may flow downslope, in Ireland such flows are known as bog-bursts. Other factors in solifluction are, sparse vegetation, snow melt, Solifluction should not be confused with earthflow, which is a much more rapid process. It was suggested that solifluction might be active on Mars, even relatively recently, Solifluction, a Component of Subaërial Denudation, The Journal of Geology, Vol.14, No.
Easterbrook, Don J. Surface Processes and Landforms, upper Saddle River, NJ, Prentice Hall,1999 Solifluction Encyclopædia Britannica Online. Web.10 Oct.2013 Stone run Frost weathering