1.
Gravity wave
–
In fluid dynamics, gravity waves are waves generated in a fluid medium or at the interface between two media when the force of gravity or buoyancy tries to restore equilibrium. An example of such an interface is that between the atmosphere and the ocean, which rise to wind waves. A gravity wave results when fluid is displaced from a position of equilibrium, the restoration of the fluid to equilibrium will produce a movement of the fluid back and forth, called a wave orbit. Gravity waves on an interface of the ocean are called surface gravity waves or surface waves. Wind-generated waves on the surface are examples of gravity waves, as are tsunamis. Wind-generated gravity waves on the surface of the Earths ponds, lakes, seas. Shorter waves are affected by surface tension and are called gravity–capillary waves. Alternatively, so-called infragravity waves, which are due to nonlinear wave interaction with the wind waves, have periods longer than the accompanying wind-generated waves. In the Earths atmosphere, gravity waves are a mechanism that produce the transfer of momentum from the troposphere to the stratosphere and mesosphere, Gravity waves are generated in the troposphere by frontal systems or by airflow over mountains. At first, waves propagate through the atmosphere without appreciable change in mean velocity, but as the waves reach more rarefied air at higher altitudes, their amplitude increases, and nonlinear effects cause the waves to break, transferring their momentum to the mean flow. This transfer of momentum is responsible for the forcing of the many large-scale dynamical features of the atmosphere, thus, this process plays a key role in the dynamics of the middle atmosphere. The effect of gravity waves in clouds can look like altostratus undulatus clouds, and are confused with them. The phase velocity c of a gravity wave with wavenumber k is given by the formula c = g k. When surface tension is important, this is modified to c = g k + σ k ρ, where σ is the surface tension coefficient and ρ is the density. Since c = ω / k is the speed in terms of the angular frequency ω and the wavenumber. The group velocity of a wave is given by c g = d ω d k, the group velocity is one half the phase velocity. A wave in which the group and phase velocities differ is called dispersive, Gravity waves traveling in shallow water, are nondispersive, the phase and group velocities are identical and independent of wavelength and frequency. When the water depth is h, c p = c g = g h, wind waves, as their name suggests, are generated by wind transferring energy from the atmosphere to the oceans surface, and capillary-gravity waves play an essential role in this effect
Gravity wave
–
Surface gravity wave, breaking on an ocean beach.
Gravity wave
–
Wave clouds over
Theresa, Wisconsin, United States.
Gravity wave
–
Atmospheric gravity waves as seen from space.
2.
Wake
–
The wake is the region of disturbed flow downstream of a solid body moving through a fluid, caused by the flow of the fluid around the body. Parachutes deployed into wakes suffer dynamic pressure deficits which reduce their expected drag forces, example applications include rocket stage separation and aircraft store separation. In incompressible fluids such as water, a bow wake is created when a watercraft moves through the medium, as the medium cannot be compressed, it must be displaced instead, resulting in a wave. As with all forms, it spreads outward from the source until its energy is overcome or lost. The non-dimensional parameter of interest is the Froude number, waterfowl and boats moving across the surface of water produce a wake pattern, first explained mathematically by Lord Kelvin and known today as the Kelvin wake pattern. This pattern consists of two lines that form the arms of a chevron, V, with the source of the wake at the vertex of the V. For sufficiently slow motion, each line is offset from the path of the wake source by around arcsin =19. 47° and is made up of feathery wavelets angled at roughly 53° to the path. The inside of the V is filled with transverse curved waves and this pattern is independent of the speed and size of the wake source over a significant range of values. However, the changes at high speeds, viz. above a hull Froude number of approximately 0.5. The angles in this pattern are not intrinsic properties of water, Any isentropic. Furthermore, this phenomenon has nothing to do with turbulence, everything discussed here is based on the linear theory of an ideal fluid, cf. Airy wave theory. Parts of the pattern may be obscured by the effects of propeller wash, and tail eddies behind the boats stern, and by the boat being a large object and not a point source. The water need not be stationary, but may be moving as in a river. This formula implies that the velocity of a deep water wave is half of its phase velocity. Two velocity parameters of importance for the pattern are, v is the relative velocity of the water. C is the velocity of a wave, varying with wave frequency. As the surface moves, it continuously generates small disturbances which are the sum of sinusoidal waves with a wide spectrum of wavelengths. Those waves with the longest wavelengths have phase speeds above v, other waves with phase speeds at or below v, however, are amplified through constructive interference and form visible shock waves, stationary in position w. r. t
Wake
–
Wake pattern generated by a small boat.
Wake
–
Wave cloud pattern in the wake of the
Île Amsterdam (lower left, at the "tip" of the triangular formation of clouds) in the southern
Indian Ocean
Wake
–
Cloud wakes from the
Juan Fernández Islands
Wake
–
Wake patterns in cloud cover over Possession Island, East Island, Ile aux Cochons, Ile de Pingouins
3.
Indian Ocean
–
The Indian Ocean is the third largest of the worlds oceanic divisions, covering 70,560,000 km2. It is bounded by Asia on the north, on the west by Africa, on the east by Australia, the Indian Ocean is known as Ratnākara, the mine of gems in ancient Sanskrit literature, and as Hind Mahāsāgar, in Hindi. The northernmost extent of the Indian Ocean is approximately 30° north in the Persian Gulf, the oceans continental shelves are narrow, averaging 200 kilometres in width. An exception is found off Australias western coast, where the width exceeds 1,000 kilometres. The average depth of the ocean is 3,890 m and its deepest point is Diamantina Deep in Diamantina Trench, at 8,047 m deep, Sunda Trench has a depth of 7, 258–7,725 m. North of 50° south latitude, 86% of the basin is covered by pelagic sediments. The remaining 14% is layered with terrigenous sediments, glacial outwash dominates the extreme southern latitudes. The major choke points include Bab el Mandeb, Strait of Hormuz, the Lombok Strait, the Strait of Malacca, the Indian Ocean is artificially connected to the Mediterranean Sea through the Suez Canal, which is accessible via the Red Sea. All of the Indian Ocean is in the Eastern Hemisphere and the centre of the Eastern Hemisphere is in this ocean, marginal seas, gulfs, bays and straits of the Indian Ocean include, The climate north of the equator is affected by a monsoon climate. Strong north-east winds blow from October until April, from May until October south, in the Arabian Sea the violent Monsoon brings rain to the Indian subcontinent. In the southern hemisphere, the winds are milder. When the monsoon winds change, cyclones sometimes strike the shores of the Arabian Sea, the Indian Ocean is the warmest ocean in the world. Long-term ocean temperature records show a rapid, continuous warming in the Indian Ocean, Indian Ocean warming is the largest among the tropical oceans, and about 3 times faster than the warming observed in the Pacific. Research indicates that human induced greenhouse warming, and changes in the frequency, among the few large rivers flowing into the Indian Ocean are the Zambezi, Shatt al-Arab, Indus, Godavari, Krishna, Narmada, Ganges, Brahmaputra, Jubba and Irrawaddy River. The oceans currents are controlled by the monsoon. Two large gyres, one in the northern hemisphere flowing clockwise and one south of the equator moving anticlockwise, during the winter monsoon, however, currents in the north are reversed. Deep water circulation is controlled primarily by inflows from the Atlantic Ocean, the Red Sea, north of 20° south latitude the minimum surface temperature is 22 °C, exceeding 28 °C to the east. Southward of 40° south latitude, temperatures drop quickly, surface water salinity ranges from 32 to 37 parts per 1000, the highest occurring in the Arabian Sea and in a belt between southern Africa and south-western Australia
Indian Ocean
–
The economically important
Silk Road (red) and spice
trade routes (blue) were blocked by the
Ottoman Empire in ca. 1453 with the fall of the
Byzantine Empire. This spurred exploration, and a new sea route around Africa was found, triggering the
Age of Discovery.
Indian Ocean
–
Extent of the Indian Ocean according to the
CIA World Factbook
Indian Ocean
–
British heavy cruisers
Dorsetshire and
Cornwall under Japanese air attack and heavily damaged on 5 April 1942
Indian Ocean
–
A
dhow off the coast of Kenya
4.
Wave cloud
–
A wave cloud is a cloud form created by atmospheric internal waves. As an air mass travels through the wave, it undergoes repeated uplift, if there is enough moisture in the atmosphere, clouds will form at the cooled crests of these waves. In the descending part of the wave, those clouds will evaporate due to heating, leading to the characteristic clouded. The cloud base on the side is higher than on the windward side. It is possible that simple convection from mountain summits can also form wave clouds and this occurs as the convection forces a wave or lenticular wave cloud into the more stable air above. Wave clouds are typically mid- to upper-tropospheric ice clouds and they are relatively easy to study, because they are quite consistent. As a result, they are being analyzed to increase our understanding of how these upper-level ice clouds influence the Earths radiation budget, understanding this can improve climate models. The streamlines in these clouds have the steepest slope a few kilometers downwind of the lee slope of a mountain and it is in these regions of highest vertical velocity that sailplanes can reach record-breaking altitudes. Wave cloud structure ranges from smooth and simple, to jumbled phases occurring randomly, often, ice crystals can be found downwind of the waves. Whether this happens depends on the saturation of the air, the composition of the ice is currently an active topic of study. The main mechanism for ice formation is homogeneous nucleation, the ice crystals are mostly small spheroidal and irregular-shaped particles. Ice columns make up less than 1%, and plates are virtually nonexistent, multi-level mountain wave clouds form when the moisture in the air above the mountain is located in distinct layers, and vertical mixing is inhibited
Wave cloud
–
This wave cloud pattern formed over the
Île Amsterdam, in the lower left corner at the tip of the triangular formation, in the far southern
Indian Ocean.
Wave cloud
–
Wave cloud pattern in
Tadrart region.
Wave cloud
–
Extensive wave cloud at
Burra, South Australia on 16 Jan 2007.
Wave cloud
–
Unusual wave clouds over the
Aral Sea, seen from NASA's
Aqua satellite on March 12, 2009.
5.
Air mass
–
In meteorology, an air mass is a volume of air defined by its temperature and water vapor content. Air masses cover many hundreds or thousands of miles. They are classified according to latitude and their continental or maritime source regions, colder air masses are termed polar or arctic, while warmer air masses are deemed tropical. Continental and superior air masses are dry while maritime and monsoon air masses are moist, weather fronts separate air masses with different density characteristics. Once an air mass moves away from its region, underlying vegetation. Classification schemes tackle an air mass characteristics, as well as modification, the Bergeron classification is the most widely accepted form of air mass classification, though others have produced more refined versions of this scheme over different regions of the globe. Air mass classification involves three letters, the first letter describes its moisture properties, with c used for [[continental air masses and m for maritime air masses. The second letter describes the characteristic of its source region, T for Tropical, P for Polar, A for arctic or Antarctic, M for monsoon, E for Equatorial. For instance, an air mass originating over the desert southwest of the United States in summer may be designated cT, an air mass originating over northern Siberia in winter may be indicated as cA. The stability of an air mass may be using a third letter, either k or w. An example of this might be an air mass blowing over the Gulf Stream. For example, a series of fronts over the Pacific might show an air mass denoted mPk followed by another denoted mPk, another convention utilizing these symbols is the indication of modification or transformation of one type to another. For instance, an Arctic air mass blowing out over the Gulf of Alaska may be shown as cA-mPk, yet another convention indicates the layering of air masses in certain situations. For instance, the overrunning of an air mass by an air mass from the Gulf of Mexico over the Central United States might be shown with the notation mT/cP. Arctic, Antarctic, and polar air masses are cold, the qualities of arctic air are developed over ice and snow-covered ground. Arctic air is cold, colder than polar air masses. Arctic air can be shallow in the summer, and rapidly modify as it moves equatorward, Polar air masses develop over higher latitudes over the land or ocean, are very stable, and generally shallower than arctic air. Polar air over the ocean loses its stability as it gains moisture over warmer ocean waters, Tropical and equatorial air masses are hot as they develop over lower latitudes
Air mass
–
Lake-effect snow bands near the
Korean Peninsula
Air mass
–
Different air masses which affect North America, as well as other continents, tend to be separated by frontal boundaries
6.
Elevation
–
GIS or geographic information system is a computer system that allows for visualizing, manipulating, capturing, and storage of data with associated attributes. GIS offers better understanding of patterns and relationships of the landscape at different scales, tools inside the GIS allow for manipulation of data for spatial analysis or cartography. A topographical map is the type of map used to depict elevation. In a Geographic Information System, digital models are commonly used to represent the surface of a place. Digital terrain models are another way to represent terrain in GIS, USGS is developing a 3D Elevation Program to keep up with growing needs for high quality topographic data. 3DEP is a collection of enhanced elevation data in the form of high quality LiDAR data over the conterminous United States, Hawaii, there are three bare earth DEM layers in 3DEP which are nationally seamless at the resolution of 1/3,1, and 2 arcseconds. This map is derived from GTOPO30 data that describes the elevation of Earths terrain at intervals of 30 arcseconds and it uses color and shading instead of contour lines to indicate elevation. Hypsography is the study of the distribution of elevations on the surface of the Earth, the term originates from the Greek word ὕψος hypsos meaning height. Most often it is used only in reference to elevation of land, related to the term hypsometry, the measurement of these elevations of a planets solid surface are taken relative to mean datum, except for Earth which is taken relative to the sea level. In the troposphere, temperatures decrease with altitude and this lapse rate is approximately 6.5 °C/km. S
Elevation
–
A sign at 8000 feet (2438 meters) in the
San Bernardino Mountains.
Elevation
–
Elevation
histogram of the surface of the Earth – approximately 71% of the Earth's surface is covered with water.
Elevation
Elevation
–
Part of a
topographic map of
Haleakala (
Hawaii), showing elevation.
7.
Terrain
–
Terrain or relief is the vertical and horizontal dimension of the land surface. When relief is described underwater, the term bathymetry is used, the Latin Word Terra, is Earth. Terrain is used as a term in physical geography, referring to the lay of the land. This is usually expressed in terms of the elevation, slope, terrain affects surface water flow and distribution. Over a large area, it can affect weather and climate patterns, complex arrays of relief data are used as input parameters for hydrology transport models to allow prediction of river water quality. Understanding terrain also supports soil conservation, especially in agriculture, contour ploughing is an established practice enabling sustainable agriculture on sloping land, it is the practice of ploughing along lines of equal elevation instead of up and down a slope. Terrain is militarily critical because it determines the ability of armed forces to take and hold areas, an understanding of terrain is basic to both defensive and offensive strategy. Terrain is important in determining weather patterns, two areas geographically close to each other may differ radically in precipitation levels or timing because of elevation differences or a rain shadow effect. Precise knowledge of terrain is vital in aviation, especially for low-flying routes and maneuvers, terrain will also affect range and performance of radars and terrestrial radio navigation systems. Furthermore, a hilly or mountainous terrain can strongly impact the implementation of a new aerodrome, relief refers specifically to the quantitative measurement of vertical elevation change in a landscape. It is the difference between maximum and minimum elevations within an area, usually of limited extent. The relief of a landscape can change with the size of the area over which it is measured, making the definition of the scale over which it is measured very important. Because it is related to the slope of surfaces within the area of interest and to the gradient of any streams present, the relief of a landscape is a useful metric in the study of the Earths surface. Relief energy, which may be defined inter alia as the height range in a regular grid, is essentially an indication of the ruggedness or relative height of the terrain. Geomorphology is in part the study of the formation of terrain or topography. Terrain is formed by intersecting processes, Geological processes, Migration of tectonic plates, faulting and folding, volcanic eruptions, erosional processes, water and wind erosion, landslides. Tectonic processes such as orogenies cause land to be elevated, land surface parameters are quantitative measures of various morphometric properties of a surface. The most common examples are used to derive slope or aspect of a terrain or curvatures at each location and these measures can also be used to derive hydrological parameters that reflect flow/erosion processes
Terrain
–
A shaded and colored image (i.e. terrain is enhanced) of varied terrain from the
Shuttle Radar Topography Mission. This shows
elevation model of New Zealand's
Alpine Fault running about 500 km (300 mi) long. The
escarpment is flanked by a vast chain of hills between the
fault and the
mountains of
New Zealand 's
Southern Alps. Northeast is towards the top.
Terrain
–
Present-day
Earth altimetry and
bathymetry. Data from the
National Geophysical Data Center 's TerrainBase Digital Terrain Model.
8.
Altitude
–
Altitude or height is defined based on the context in which it is used. As a general definition, altitude is a measurement, usually in the vertical or up direction. The reference datum also often varies according to the context, although the term altitude is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage. Vertical distance measurements in the direction are commonly referred to as depth. In aviation, the altitude can have several meanings, and is always qualified by explicitly adding a modifier. Parties exchanging altitude information must be clear which definition is being used, aviation altitude is measured using either mean sea level or local ground level as the reference datum. When flying at a level, the altimeter is always set to standard pressure. On the flight deck, the instrument for measuring altitude is the pressure altimeter. There are several types of altitude, Indicated altitude is the reading on the altimeter when it is set to the local barometric pressure at mean sea level. In UK aviation radiotelephony usage, the distance of a level, a point or an object considered as a point, measured from mean sea level. Absolute altitude is the height of the aircraft above the terrain over which it is flying and it can be measured using a radar altimeter. Also referred to as radar height or feet/metres above ground level, true altitude is the actual elevation above mean sea level. It is indicated altitude corrected for temperature and pressure. Height is the elevation above a reference point, commonly the terrain elevation. Pressure altitude is used to indicate flight level which is the standard for reporting in the U. S. in Class A airspace. Pressure altitude and indicated altitude are the same when the setting is 29.92 Hg or 1013.25 millibars. Density altitude is the altitude corrected for non-ISA International Standard Atmosphere atmospheric conditions, aircraft performance depends on density altitude, which is affected by barometric pressure, humidity and temperature. On a very hot day, density altitude at an airport may be so high as to preclude takeoff and these types of altitude can be explained more simply as various ways of measuring the altitude, Indicated altitude – the altitude shown on the altimeter
Altitude
–
Vertical distance comparison
9.
Adiabatic cooling
–
In thermodynamics, an adiabatic process is one that occurs without transfer of heat or matter between a thermodynamic system and its surroundings. In an adiabatic process, energy is transferred only as work, the adiabatic process provides a rigorous conceptual basis for the theory used to expound the first law of thermodynamics, and as such it is a key concept in thermodynamics. The adiabatic flame temperature is the temperature that would be achieved by a if the process of combustion took place in the absence of heat loss to the surroundings. A process that does not involve the transfer of heat or matter into or out of a system, so that Q =0, is called an adiabatic process, the assumption that a process is adiabatic is a frequently made simplifying assumption. Even though the cylinders are not insulated and are quite conductive, the same can be said to be true for the expansion process of such a system. The assumption of adiabatic isolation of a system is a useful one, the behaviour of actual machines deviates from these idealizations, but the assumption of such perfect behaviour provide a useful first approximation of how the real world works. According to Laplace, when sound travels in a gas, there is no loss of heat in the medium and the propagation of sound is adiabatic. For this adiabatic process, the modulus of elasticity E = γP where γ is the ratio of specific heats at constant pressure and at constant volume, such a process is called an isentropic process and is said to be reversible. Fictively, if the process is reversed, the energy added as work can be recovered entirely as work done by the system, if the walls of a system are not adiabatic, and energy is transferred in as heat, entropy is transferred into the system with the heat. Such a process is neither adiabatic nor isentropic, having Q >0, naturally occurring adiabatic processes are irreversible. The transfer of energy as work into an isolated system can be imagined as being of two idealized extreme kinds. In one such kind, there is no entropy produced within the system, in nature, this ideal kind occurs only approximately, because it demands an infinitely slow process and no sources of dissipation. The other extreme kind of work is work, for which energy is added as work solely through friction or viscous dissipation within the system. The second law of thermodynamics observes that a process, of transfer of energy as work, always consists at least of isochoric work. Every natural process, adiabatic or not, is irreversible, with ΔS >0, the adiabatic compression of a gas causes a rise in temperature of the gas. Adiabatic expansion against pressure, or a spring, causes a drop in temperature, in contrast, free expansion is an isothermal process for an ideal gas. Adiabatic heating occurs when the pressure of a gas is increased from work done on it by its surroundings and this finds practical application in diesel engines which rely on the lack of quick heat dissipation during their compression stroke to elevate the fuel vapor temperature sufficiently to ignite it. Adiabatic heating occurs in the Earths atmosphere when an air mass descends, for example, in a wind, Foehn wind
Adiabatic cooling
–
For a simple substance, during an adiabatic process in which the volume increases, the
internal energy of the working substance must decrease
10.
Relative humidity
–
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 temperature and the pressure of the system of interest and it requires less water vapor to attain high relative humidity at low temperatures, more water vapour is required to attain high relative humidity in warm or hot air. Humans are sensitive to high humidity because the body uses evaporative cooling, enabled by perspiration. Perspiration evaporates from the more slowly under humid conditions than under arid. For example, if the air temperature is 24 °C and the humidity is zero percent. If the relative humidity is 100 percent at the air temperature. In other words, if the air is 24 °C and contains saturated water vapor, then the human body cools itself at the rate as it would if it were 27 °C. The heat index and the humidex are indices that reflect the effect of temperature. In cold climates, the temperature causes lower capacity for water vapour to flow about. Dry cracked skin can result from dry air, low humidity causes tissue lining nasal passages to dry, crack and become more susceptible to penetration of Rhinovirus cold viruses. Low humidity is a cause of nosebleeds. The use of a humidifier in homes, especially bedrooms, can help with these symptoms, indoor relative humidities should be kept above 30% to reduce the likelihood of the occupants nasal passages drying out. Humans can be comfortable within a range of humidities depending on the temperature—from thirty to seventy percent—but ideally between 50% and 60%. Very low humidity can create discomfort, respiratory problems, and aggravate allergies in some individuals, in the winter, it is advisable to maintain relative humidity at 30 percent or above. Extremely low relative humidities may also cause eye irritation, wooden furniture can shrink, causing the paint that covers these surfaces to fracture. When the temperature is low and the humidity is high. When relative humidity approaches 100 percent, condensation can occur on surfaces, leading to problems with mold, corrosion, decay, condensation can pose a safety risk as it can promote the growth of mold and wood rot as well as possibly freezing emergency exits shut. The basic principles for buildings, above, also apply to vehicles, in addition, there may be safety considerations
Relative humidity
–
Humidity and hygrometry
11.
Cloud
–
The experiment began operation in November 2009. The primary goal is to understand the influence of cosmic rays on aerosols and clouds. Although its design is optimised to address the cosmic ray question, CLOUD allows as well to measure aerosol nucleation, atmospheric aerosols and their effect on clouds are recognised by the IPCC as main source of uncertainty in present radiative forcing and climate models. The core of the experiment is a steel chamber of 26m³ volume filled with synthetic air made from liquid nitrogen. The chamber atmosphere and pressure is being measured and regulated by various instrumentations, the aerosol chamber can be exposed to an adjustable particle beam simulating GCRs at various altitude or latitude. The chamber contains a field cage to control the drift of small ions. The ionisation produced by cosmic rays can be removed with an electric field. Besides, humidity and temperature inside the chamber can be regulated, CERN posted a 2009 progress report on the CLOUD project. J. Kirkby reviews developments in the CERN CLOUD project and planned tests and he describes cloud nucleation mechanisms which appear energetically favourable and depend on GCRs. On 24 August 2011, preliminary research published in the journal Nature showed there was a connection between Cosmic Rays and aerosol nucleation, the first CLOUD experiments showed that sulphuric acid as such has a much smaller effect than had been assumed. In 2014, CLOUD researchers presented newer experimental results showing an interaction between oxidised biogenic vapours and sulphuric acid and this new process may account for seasonal variations in atmospheric aerosol particles, which are being related to higher global tree emissions in the northern hemisphere summer. Besides biogenic vapours produced by plants, another class of trace vapours and these are found close to their primary sources, e. g. animal husbandry, while alpha-pinene is generally found over landmasses. The experiments show that sulfuric acid and oxidized organic vapors at low concentrations reproduce suitable particle nucleation rates, CLOUD insofar allows to explain a large fraction of cloud seeds in the lower atmosphere involving sulphuric acid and biogenic aerosols. This result does not support the hypothesis that cosmic rays significantly affect climate, dunne et al. have presented the main outcomes of 10 years of results obtained at the CLOUD experiment performed at CERN. They have studied in detail the physico-chemical mechanisms and the kinetics of aerosols formation
Cloud
12.
Precipitation (meteorology)
–
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, graupel, Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and precipitates. Thus, fog and mist are not precipitation but suspensions, because the vapor does not condense sufficiently to precipitate. Two processes, possibly acting together, can lead to air becoming saturated, 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 that is 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 is occurring. A stationary front is often present near the area of freezing rain, provided necessary and sufficient atmospheric moisture content, the moisture within the rising air will condense into clouds, namely stratus and cumulonimbus. Eventually, the droplets will grow large enough to form raindrops. Lake-effect snowfall can be locally heavy, thundersnow is possible within a cyclones comma head and 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. The movement of the trough, or intertropical convergence zone. Precipitation is a component of the water cycle, and is responsible for depositing the fresh water on the planet. Approximately 505,000 cubic kilometres of water falls as precipitation each year,398,000 cubic kilometres of it over the oceans and 107,000 cubic kilometres over land. Given the Earths surface area, that means the globally averaged annual precipitation is 990 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 celestial bodies, e. g. when it gets cold, Mars has precipitation which most likely takes the form of frost. Precipitation is a component of the water cycle, and is responsible for depositing most of the fresh water on the planet. Approximately 505,000 km3 of water falls as precipitation each year,398,000 km3 of it over the oceans, given the Earths surface area, that means the globally averaged annual precipitation is 990 millimetres. Mechanisms of producing precipitation include convective, stratiform, and orographic rainfall, 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
Precipitation (meteorology)
–
A thunderstorm with heavy precipitation
Precipitation (meteorology)
–
Long-term mean precipitation by month
Precipitation (meteorology)
–
Late-summer
rainstorm in
Denmark
Precipitation (meteorology)
–
Lenticular cloud forming due to mountains over Wyoming
13.
Rain shadow
–
A rain shadow is a dry area on the leeward side of a mountainous area. The mountains block the passage of rain-producing weather systems and cast a shadow of dryness behind them, wind and moist air is drawn by the prevailing winds towards the top of the mountains, where it condenses and precipitates before it crosses the top. The air, without much moisture left, advances behind the mountains creating a side called the rain shadow. The condition exists because warm moist air rises by orographic lifting to the top of a mountain range, as atmospheric pressure decreases with increasing altitude, the air has expanded and adiabatically cooled to the point that the air reaches its adiabatic dew point. At the adiabatic dew point, moisture condenses onto the mountain and it precipitates on the top, the air descends on the leeward side, but due to the precipitation it has lost much of its moisture. There are regular patterns of prevailing winds found in round the Earths equatorial region. The zone designated the trade winds is the zone between about 30° N and 30° S, blowing predominantly from the northeast in the Northern Hemisphere, the strongest westerly winds in the middle latitudes can come in the Roaring Forties between 30 and 50 degrees latitude. The Dasht-i-Lut in Iran is in the shadow of the Elburz. The Ordos Desert is rain shadowed by mountain chains including the Kara-naryn-ula, the Sheitenula, and the Yin Mountains, which link on to the south end of the Great Khingan Mountains. The Thar desert is bounded and rain shadowed by the Aravalli ranges to the south-east, the Himalaya to the northeast, Eastern Side of Sahyadri ranges on Deccan e. g. Northern Karnataka & Solapur, Beed, Osmanabad and Vidharba Plateau of India. The central region of Myanmar is in the shadow of the Arakan Mountains and is almost semi-arid with only 750 millimetres of rain as against as much as 5.5 metres on the Rakhine State coast. The High Peaks of Mount Lebanon rain-shadow the northern parts of the Beqaa Valley, the Judean Desert, the Dead Sea and the western slopes of the Moab Mountains on the opposite side are rain-shadowed by the Judean Hills. The Atacama Desert in Chile is the driest non-polar desert on Earth because it is blocked from moisture on both sides, Cuyo and Eastern Patagonia is rain shadowed from the prevailing westerly winds by the Andes range and is arid. The Argentinian wine region of Cuyo and Northern Patagonia is almost completely dependent on irrigation, on the largest scale, the entirety of the North American Interior Plains are shielded from the prevailing Westerlies carrying moist Pacific weather by the North American Cordillera. More pronounced effects are observed, however, in valley regions within the Cordillera. Most rainshadows in the western United States are due to the Sierra Nevada, champlain Valley in upstate New York. It is protected by the Adirondack Mountains, hawaii also has rain shadows, with some areas being desert. Orographic lifting produces the worlds second-highest annual precipitation record,12.7 meters, on the island of Kauai, the entire island of Kahoolawe lies in the rain shadow of Mauis East Maui Volcano
Rain shadow
–
An example of a rain shadow.
Rain shadow
–
The
Tibetan Plateau (top), perhaps the best example of a rain shadow. Rain does not make it past the
Himalayas, leading to an arid climate on the leeward side of the
mountain range.
Rain shadow
–
The
Agasthiyamalai hills cut off
Tirunelveli (
India) from the
monsoons, creating a rainshadow region
14.
Mogollon Rim
–
The Mogollon Rim or /mɒɡɒdʒɔːn/) is a topographical and geological feature cutting across the U. S. state of Arizona. It extends approximately 200 miles, starting in northern Yavapai County and running eastward and it forms the southern edge of the Colorado Plateau in Arizona. The Rim is an escarpment defining the southwestern edge of the Colorado Plateau and its central and most spectacular portions are characterized by high cliffs of limestone and sandstone, namely the Kaibab Limestone and Coconino Sandstone cliffs. The escarpment was created by erosion and faulting, cutting dramatic canyons into it, including Fossil Creek Canyon, the name Mogollon comes from Don Juan Ignacio Flores Mogollón, the Spanish Governor of New Mexico from 1712 to 1715. The Mogollon Rims limestones and sandstones were formed from sediments deposited in the Carboniferous, several of the Rims rock formations are also seen on the walls of the Grand Canyon. In many places, the Rim is capped or even buried by the basaltic lava flows. The uppermost sandstone stratum of the Mogollon Rim, called the Coconino Sandstone, forms spectacular white cliffs and this formation of the Permian Period is of aeolian origin and is one of the thickest sand-dune-derived sandstones on earth. Cities and towns near the Mogollon Rim include Payson, Sedona, Show Low, Alpine, the Mogollon Rim is practically bisected by Interstate 17 which runs north-to-south between Flagstaff and Phoenix. In June 2002, the portion of the Mogollon Rim was the site of Arizonas second-largest wildfire. The Mogollon Rim was also the site of the Dude fire that started on June 25,1990 and this fire grew to cover over 30,000 acres and killed six wildland firefighters. Other large fires have burned along the Mogollon Rim since 1990, and the ponderosa pine forests remain vulnerable because of past fire-suppression efforts. Western novel author Zane Grey built a cabin on the slopes of the Mogollon Rim just northeast of Payson. The cabin was restored by the Phoenix air-conditioning magnate William Goettl during the late 1960s, louis LAmours novel The Sackett Brand, set near the Mogollon Rim, includes descriptions of its cliffs. Hellsgate Wilderness Mogollon Monster Mogollon Mountains Pinyon-juniper woodland Mogollon Rim recreation, Coconino National Forest Land Use History of the Mogollon Rim, Arizona
Mogollon Rim
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View of Mogollon Rim, east of
Pine, Arizona
Mogollon Rim
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View from Mogollon Rim near
Payson, Arizona
Mogollon Rim
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Site of Zane Grey's lodge
15.
Sierra Nevada (U.S.)
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The Sierra Nevada is a mountain range in the Western United States, between the Central Valley of California and the Basin and Range Province. The vast majority of the lies in the state of California. The Sierra runs 400 miles north-to-south, and is approximately 70 miles across east-to-west, the Sierra is home to three national parks, twenty wilderness areas, and two national monuments. These areas include Yosemite, Sequoia, and Kings Canyon National Parks, the character of the range is shaped by its geology and ecology. More than one hundred years ago during the Nevadan orogeny. The range started to uplift four M. A. ago, the uplift caused a wide range of elevations and climates in the Sierra Nevada, which are reflected by the presence of five life zones. Uplift continues due to faulting caused by forces, creating spectacular fault block escarpments along the eastern edge of the southern Sierra. The Sierra Nevada has a significant history, the California Gold Rush occurred in the western foothills from 1848 through 1855. Due to inaccessibility, the range was not fully explored until 1912, the Sierra Nevada lies in Central and Eastern California, with a very small but historically important spur extending into Nevada. West-to-east, the Sierra Nevadas elevation increases gradually from 1,000 feet in the Central Valley to an height of about 10,500 feet at its crest only 50–75 miles to the east. The east slope forms the steep Sierra Escarpment, unlike its surroundings, the range receives a substantial amount of snowfall and precipitation due to orographic lift. The Sierra Nevada stretches from the Susan River and Fredonyer Pass in the north to Tehachapi Pass in the south and it is bounded on the west by Californias Central Valley and on the east by the Basin and Range Province. The geographical boundary between the Sierra and the Cascades is virtually indistinguishable, with the Fredonyer Pass designation being traditional, physiographically, the Sierra is a section of the Cascade-Sierra Mountains province, which in turn is part of the larger Pacific Mountain System physiographic division. The range is drained on its western slope by the Central Valley watershed, the northern third of the western Sierra is part of the Sacramento River watershed, and the middle third is drained by the San Joaquin River. The eastern slope watershed of the Sierra is much narrower, its rivers flow out into the endorheic Great Basin of eastern California and western Nevada. Although none of the eastern rivers reach the sea, many of the streams from Mono Lake southwards are diverted into the Los Angeles Aqueduct which provides water to Southern California, the height of the mountains in the Sierra Nevada increases gradually from north to south. Between Fredonyer Pass and Lake Tahoe, the range from 5,000 feet to more than 9,000 feet. The crest near Lake Tahoe is roughly 9,000 feet high, farther south, the highest peak in Yosemite National Park is Mount Lyell
Sierra Nevada (U.S.)
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The Sierra's
Mills Creek cirque (center) is on the west side of the
Sierra Crest, south of
Mono Lake (top, blue).
Sierra Nevada (U.S.)
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Mount Whitney, the highest peak in the range and the contiguous United States
Sierra Nevada (U.S.)
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The Sierra hosts many waterways, such as the
Tuolumne River.
Sierra Nevada (U.S.)
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Mount Tallac above
Lake Tahoe
16.
Mawsynram
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Mawsynram is a village in the East Khasi Hills district of Meghalaya state in north-eastern India,65 kilometres from Shillong. According to the Guinness Book of World Records, Mawsynram received 26,000 millimetres of rainfall in 1985. Mawsynram is located at 25° 18′ N, 91° 35′ E, at an altitude of about 1,400 metres,16 km west of Cherrapunji, in the Khasi Hills in the state of Meghalaya. The name of the village contains Maw, a Khasi word meaning stone, Khasi Hills are rich with such megaliths. Under the Köppen climate classification, Mawsynram features a subtropical climate with an extraordinarily showery and long monsoonal season. Based on the data of a recent few decades, it appears to be the wettest place in the world, Mawsynram receives nearly 10,000 millimeters of rain in an average year, and the vast majority of rain it falls during the monsoon months. A comparison of rainfalls for Cherrapunji and Mawsynram for some years is given in Table 1, primarily due to the high altitude, it seldom gets truly hot in Mawsynram. Average monthly temperatures range from around 11°C in January to just above 20°C in August, the village also experiences a brief but noticeably drier season from December until February, when monthly precipitation on average does not exceed 30 millimetres. The little precipitation during the village’s “low sun” season is something that is shared by many areas with this type of climate, Table 1, Comparison of rainfalls for Cherrapunji and Mawsynram from 1970. The alignment of the Khasi Hills places them directly in the path of the airflow from the Bay of Bengal, located in Mawsynram, is a cave named Mawjymbuin, known for its stalagmites. Inside this cave is a pair of notable speleothems - breast-shaped stalactite over a massive stalagmite, the area is known for its many caves, commercialised and non-commercialised, which contain remnants of a past that tells us of the history of the plateau that was once under water. The Tribune - The dispute between Mawsynram and Cherrapunji for the title of wettest place on earth
Mawsynram
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Nature made stalagmite Shivalinga in Mawjymbuin Cave, Mawsynram Meghalaya.
17.
Yemen
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Yemen, officially known as the Republic of Yemen, is an Arab country in Western Asia, occupying South Arabia, the southern end of the Arabian Peninsula. Yemen is the second-largest country in the peninsula, occupying 527,970 km2, the coastline stretches for about 2,000 km. It is bordered by Saudi Arabia to the north, the Red Sea to the west, the Gulf of Aden and Arabian Sea to the south, although Yemens constitutionally stated capital is the city of Sanaa, the city has been under rebel control since February 2015. Because of this, Yemens capital has been relocated to the port city of Aden. Yemens territory includes more than 200 islands, the largest of these is Socotra, Yemen was the home of the Sabaeans, a trading state that flourished for over a thousand years and probably also included parts of modern-day Ethiopia and Eritrea. In 275 AD, the region came under the rule of the later Jewish-influenced Himyarite Kingdom, Christianity arrived in the fourth century, whereas Judaism and local paganism were already established. Islam spread quickly in the century and Yemenite troops were crucial in the expansion of the early Islamic conquests. Administration of Yemen has long been notoriously difficult, several dynasties emerged from the ninth to 16th centuries, the Rasulid dynasty being the strongest and most prosperous. The country was divided between the Ottoman and British empires in the twentieth century. The Zaydi Mutawakkilite Kingdom of Yemen was established after World War I in North Yemen before the creation of the Yemen Arab Republic in 1962, South Yemen remained a British protectorate known as the Aden Protectorate until 1967 when it became an independent state and later, a Marxist state. The two Yemeni states united to form the modern republic of Yemen in 1990, Yemen is a developing country, and the poorest country in the Middle East. Under the rule of President Ali Abdullah Saleh, Yemen was described as a kleptocracy, according to the 2009 international corruption Perception Index by Transparency International, Yemen ranked 164 out of 182 countries surveyed. President Saleh stepped down and the powers of the presidency were transferred to Vice President Abd Rabbuh Mansur Hadi, the transitional process was disrupted by conflicts between the Houthis and al-Islah, as well as the al-Qaeda insurgency. In September 2014, the Houthis took over Sanaa, later declaring themselves in control of the government in a coup détat, since then, a Saudi-led intervention has taken place, however, it could not stop the civil war. Instead, the Saudis and the others have destroyed some hospitals, schools and homes, Yemen was mentioned in Old South Arabian inscriptions as Yamnat. In Arabic literature, the term includes much greater territory than that of the republic of Yemen. It stretches from the northern Asir Region in southwestern Saudi Arabia to Dhofar Governorate in southern Oman, one etymology derives Yemen from yumn, meaning felicity, as much of the country is fertile. The Romans called it Arabia Felix, as opposed to Arabia Deserta, al-Yaman significantly plays on the notion of the land to the right, when in Mecca facing the dawn, complementary to Al-Sham, the Land to the Left, referring to the Levant
Yemen
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Sabaean gravestone of a woman holding a stylized sheaf of wheat, a symbol of fertility in ancient Yemen
Yemen
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Flag
Yemen
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A funerary
stela featuring a musical scene, 1st century AD
Yemen
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Himyarite King Dhamar Ali Yahbur II
18.
Western Ghats
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Western Ghats மேற்கு தொடர்ச்சி மலை is a mountain range that runs parallel to the western coast of the Indian peninsula, located entirely in India. It is a UNESCO World Heritage Site and is one of the eight hottest hot-spots of biological diversity in the world and it is sometimes called the Great Escarpment of India. The range runs north to south along the edge of the Deccan Plateau. These hills cover 160,000 km2 and form the catchment area for complex riverine drainage systems that drain almost 40% of India, the Western Ghats block southwest monsoon winds from reaching the Deccan Plateau. The average elevation is around 1,200 m, at least 325 globally threatened species occur in the Western Ghats. The Western Ghats are the mountainous faulted and eroded edge of the Deccan Plateau, geologic evidence indicates that they were formed during the break-up of the supercontinent of Gondwana some 150 million years ago. Geophysical evidence indicates that the west coast of India came into being somewhere around 100 to 80 mya after it broke away from Madagascar, after the break-up, the western coast of India would have appeared as an abrupt cliff some 1,000 m in elevation. Basalt is the predominant rock found in the reaching a thickness of 3 km. Other rock types found are charnockites, granite gneiss, khondalites, leptynites, metamorphic gneisses with detached occurrences of limestone, iron ore. Residual laterite and bauxite ores are found in the southern hills. The Western Ghats extend from the Satpura Range in the north and it traverses south past the states of Maharashtra, Goa, Karnataka and Kerala. Major gaps in the range are the Goa Gap, between the Maharashtra and Karnataka sections, and the Palghat Gap on the Tamil Nadu and Kerala border between the Nilgiri Hills and the Anaimalai Hills. The mountains intercept the rain-bearing westerly monsoon winds, and are consequently an area of high rainfall, particularly on their western side. The northern portion of the coastal plain between the Western Ghats and the Arabian Sea is known as the Konkan, the central portion is called Kanara. The foothill region east of the Ghats in Maharashtra is known as Desh, the range is known as Sahyadri in Maharashtra and Karnataka. The Western Ghats meets the Eastern Ghats at Nilgiris in northwestern Tamil Nadu, Nilgiris connects Biligiriranga Hills in southeastern Karnataka with the Shevaroys and Tirumala hills. In the southern part of the range is Anamudi, the highest peak in Western Ghats, following is a list of some of the highest peaks of the Western Ghats, The Western Ghats form one of the four watersheds of India, feeding the perennial rivers of India. The major river systems originating in the Western Ghats include Godavari, Kaveri, Krishna, Thamiraparani, majority of streams draining the Western Ghats join these rivers and carry large volume of water during the monsoon months
Western Ghats
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A view of
Anamudi, the highest peak of the Western Ghats 2,695 metres (8,842 ft) from
Eravikulam National Park, Kerala.
Western Ghats
Western Ghats
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The Dense Vegetation in the Watchumaram Region towards valparai
Western Ghats
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Shola Grasslands and forests in the
Kudremukh National Park, Western Ghats,
Karnataka.
19.
Great Dividing Range
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The Great Dividing Range, or the Eastern Highlands, is Australias most substantial mountain range and the third longest land-based range in the world. The width of the range varies from about 160 km to over 300 km, the Dividing Range does not consist of a single mountain range. It consists of a complex of ranges, plateaus, upland areas and escarpments with an ancient. The physiographic division name for the landmass is called the East Australian Cordillera, in some places the terrain is relatively flat, consisting of very low hills. Typically the highlands range from 300 m to 1,600 m in height, the mountains and plateaus, which consist of limestones, sandstone, quartzite, schists and dolomite, have been created by faulting and folding processes. In the north, the rivers on the west side of the drain towards the Gulf of Carpentaria. The higher and more rugged parts of the range do not necessarily part of the crest of the range. At some places it can be up to 400 km wide, notable ranges and other features which form part of the range complex have their own distinctive names. The Great Dividing Range was formed during the Carboniferous period—over 300 million years ago—when Australia collided with what is now parts of South America, the range has experienced significant erosion since. For tens of thousands of years prior to British colonisation the ranges were home to various Aboriginal Australian nations and clans, evidence remains in some places of their traditional way of life including decorated caves, campsites and trails used to travel between the coastal and inland regions. Many descendants of these still exist today and remain the traditional owners. After British colonisation in 1788, the ranges were an obstacle to exploration, although not high, parts of the highlands were very rugged. Towns in the Blue Mountains were later named each of these men. This was the start of the development of the districts of inland New South Wales. A road was built to Blaxland by convicts within six months, easier routes to inland New South Wales were discovered towards Goulburn to the southwest, and westwards from Newcastle. Subsequent explorations were made across and around the ranges by Allan Cunningham, John Oxley, Hamilton Hume, Paul Edmund Strzelecki, Ludwig Leichhardt and these explorers were mainly concerned with finding and appropriating good agricultural land. By the late 1830s the most fertile rangelands adjacent to the ranges had been explored, appropriated from the traditional inhabitants. These included the Gippsland and Riverina regions in the south, up to the Liverpool Plains, various road and railway routes were subsequently established through many parts of the ranges, although many areas remain remote to this day
Great Dividing Range
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Great Dividing Range
Great Dividing Range
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The Great Divide dominates the eastern Australia landmass
Great Dividing Range
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Great Dividing Range sign on the
Kings Highway between
Braidwood and
Bungendore, New South Wales
Great Dividing Range
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The Snowy Mountains alpine region
20.
New Zealand
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New Zealand /njuːˈziːlənd/ is an island nation in the southwestern Pacific Ocean. The country geographically comprises two main landmasses—the North Island, or Te Ika-a-Māui, and the South Island, or Te Waipounamu—and around 600 smaller islands. New Zealand is situated some 1,500 kilometres east of Australia across the Tasman Sea and roughly 1,000 kilometres south of the Pacific island areas of New Caledonia, Fiji, because of its remoteness, it was one of the last lands to be settled by humans. During its long period of isolation, New Zealand developed a distinct biodiversity of animal, fungal, the countrys varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealands capital city is Wellington, while its most populous city is Auckland, sometime between 1250 and 1300 CE, Polynesians settled in the islands that later were named New Zealand and developed a distinctive Māori culture. In 1642, Dutch explorer Abel Tasman became the first European to sight New Zealand, in 1840, representatives of Britain and Māori chiefs signed the Treaty of Waitangi, which declared British sovereignty over the islands. In 1841, New Zealand became a colony within the British Empire, today, the majority of New Zealands population of 4.7 million is of European descent, the indigenous Māori are the largest minority, followed by Asians and Pacific Islanders. Reflecting this, New Zealands culture is derived from Māori and early British settlers. The official languages are English, Māori and New Zealand Sign Language, New Zealand is a developed country and ranks highly in international comparisons of national performance, such as health, education, economic freedom and quality of life. Since the 1980s, New Zealand has transformed from an agrarian, Queen Elizabeth II is the countrys head of state and is represented by a governor-general. In addition, New Zealand is organised into 11 regional councils and 67 territorial authorities for local government purposes, the Realm of New Zealand also includes Tokelau, the Cook Islands and Niue, and the Ross Dependency, which is New Zealands territorial claim in Antarctica. New Zealand is a member of the United Nations, Commonwealth of Nations, ANZUS, Organisation for Economic Co-operation and Development, Pacific Islands Forum, and Asia-Pacific Economic Cooperation. Dutch explorer Abel Tasman sighted New Zealand in 1642 and called it Staten Landt, in 1645, Dutch cartographers renamed the land Nova Zeelandia after the Dutch province of Zeeland. British explorer James Cook subsequently anglicised the name to New Zealand, Aotearoa is the current Māori name for New Zealand. It is unknown whether Māori had a name for the country before the arrival of Europeans. Māori had several names for the two main islands, including Te Ika-a-Māui for the North Island and Te Waipounamu or Te Waka o Aoraki for the South Island. Early European maps labelled the islands North, Middle and South, in 1830, maps began to use North and South to distinguish the two largest islands and by 1907, this was the accepted norm. The New Zealand Geographic Board discovered in 2009 that the names of the North Island and South Island had never been formalised and this set the names as North Island or Te Ika-a-Māui, and South Island or Te Waipounamu
New Zealand
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The Waitangi sheet from the
Treaty of Waitangi
New Zealand
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Flag
New Zealand
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Painting of
Mount Earnslaw by John Turnbull Thomson, oil on canvas, 1888
New Zealand
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John Key,
Prime Minister of New Zealand since 2008
21.
Westerlies
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The westerlies, anti-trades, or prevailing westerlies, are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the areas in the horse latitudes and tend towards the poles. Tropical cyclones which cross the ridge axis into the westerlies recurve due to the increased westerly flow. The winds are predominantly from the southwest in the Northern Hemisphere, the strongest westerly winds in the middle latitudes can come in the roaring forties, between 40 and 50 degrees latitude. The westerlies play an important role in carrying the warm, equatorial waters and winds to the coasts of continents. If the Earth were a planet, solar heating would cause winds across the mid-latitudes to blow in a poleward direction. This is why winds across the Northern Hemisphere tend to blow from the southwest, when pressures are lower over the poles, the strength of the westerlies increases, which has the effect of warming the mid-latitudes. This occurs when the Arctic oscillation is positive, and during low pressure near the poles is stronger than it would be during the summer. When it is negative and pressures are higher over the poles, the flow is more meridional, blowing from the direction of the pole towards the equator, throughout the year, the westerlies vary in strength with the polar cyclone. As the cyclone reaches its maximum intensity in winter, the increase in strength. As the cyclone reaches its weakest intensity in summer, the Westerlies weaken, an example of the impact of the westerlies is when dust plumes, originating in the Gobi desert combine with pollutants and spread large distances downwind, or eastward, into North America. The westerlies can be strong, especially in the Southern Hemisphere. The currents in the Northern Hemisphere are weaker than those in the Southern Hemisphere due to the differences in strength between the westerlies of each hemisphere. The process of western intensification causes currents on the boundary of an ocean basin to be stronger than those on the eastern boundary of an ocean. These western ocean currents transport warm, tropical water polewards toward the polar regions, ships crossing both oceans have taken advantage of the ocean currents for centuries. The Antarctic Circumpolar Current, or the West Wind Drift, is a current that flows from west to east around Antarctica. The ACC is the dominant circulation feature of the Southern Ocean and, at approximately 125 Sverdrups, the largest ocean current. The Kuroshio is a western boundary current in the western north Pacific Ocean, similar to the Gulf Stream
Westerlies
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Benjamin Franklin's map of the Gulf Stream
22.
Tasman Sea
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The Tasman Sea is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about 2,000 kilometres across and about 2,800 kilometres from north to south, the sea was named after the Dutch explorer Abel Janszoon Tasman, who was the first recorded European to encounter New Zealand and Tasmania. The British explorer Captain James Cook later extensively navigated the Tasman Sea in the 1770s as part of his first voyage of exploration. The Tasman Sea is informally referred to in both Australian and New Zealand English as The Ditch, for example, crossing the Ditch means travelling to Australia from New Zealand, or vice versa. The diminutive term The Ditch used for the Tasman Sea is comparable to referring to the North Atlantic Ocean as The Pond, the International Hydrographic Organization defines the limits of the Tasman Sea as follows, On the West. From the South East Rock to the North point of Three Kings Islands thence to North Cape in New Zealand, a line joining the South extreme of the foul ground off Cape Palliser and the Lighthouse on Cape Campbell. A line joining the Light on Waipapapa Point with East Head of Stewart Island, a line running from South West Cape, Stewart Island, through The Snares to North West Cape, Auckland Island, through this island to its Southern point. A line joining the Southern point of Auckland Island to South East Cape, the Tasman Seas mid-ocean ridge developed between 85 and 55 million years ago as Australia and Zealandia broke apart during the breakup of supercontinent Gondwana. It lies roughly midway between the continental margins of Australia and Zealandia, much of Zealandia is submerged, so the ridge runs much closer to the Australian coast than New Zealands. The first successful flight over the sea was accomplished by Charles Kingsford Smith later that year, the first person to row solo across the sea was Colin Quincey in 1977. The next successful crossing was completed by his son, Shaun Quincey in 2010. Axis naval activity in New Zealand waters Crossing the Ditch List of seas Media related to Tasman Sea at Wikimedia Commons
Tasman Sea
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Map of the Tasman Sea
Tasman Sea
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Location
Tasman Sea
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Smoke from the
Black Saturday bushfires crosses the southern Tasman Sea
23.
Tasmania
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Tasmania is an island state of the Commonwealth of Australia. It is located 240 km to the south of the Australian mainland, the state encompasses the main island of Tasmania, the 26th-largest island in the world, and the surrounding 334 islands. The state has a population of around 519,100, just over forty percent of which resides in the Greater Hobart precinct, Tasmanias area is 68,401 km2, of which the main island covers 64,519 km2. Though an island state, due to an error the state shares a land border with Victoria at its northernmost terrestrial point, Boundary Islet. The Bishop and Clerk Islets, about 37 km south of Macquarie Island, are the southernmost terrestrial point of the state of Tasmania, the island is believed to have been occupied by Aboriginals for 40,000 years before British colonisation. It is thought Tasmanian Aboriginals were separated from the mainland Aboriginal groups about 10,000 years ago when the sea rose to form Bass Strait. The conflict, which peaked between 1825 and 1831 and led to more than three years of law, cost the lives of almost 1100 Aboriginals and settlers. The near-destruction of Tasmanias Aboriginal population has been described by historians as an act of genocide by the British. The island was part of the Colony of New South Wales. In 1854 the present Constitution of Tasmania was passed and the year the state received permission to change its name to Tasmania. In 1901 it became a state through the process of the Federation of Australia, the state is named after Dutch explorer Abel Tasman, who made the first reported European sighting of the island on 24 November 1642. Tasman named the island Anthony van Diemens Land after his sponsor Anthony van Diemen, the name was later shortened to Van Diemens Land by the British. It was officially renamed Tasmania in honour of its first European discoverer on 1 January 1856, Tasmania was sometimes referred to as Dervon, as mentioned in the Jerilderie Letter written by the notorious Australian bushranger Ned Kelly in 1879. The colloquial expression for the state is Tassie, Tasmania is also colloquially shortened to Tas, especially when used in business names and website addresses. TAS is also the Australia Post abbreviation for the state, the reconstructed Palawa kani language name for Tasmania is Lutriwita. The island was adjoined to the mainland of Australia until the end of the last glacial period about 10,000 years ago, much of the island is composed of Jurassic dolerite intrusions through other rock types, sometimes forming large columnar joints. Tasmania has the worlds largest areas of dolerite, with many distinctive mountains, the central plateau and the southeast portions of the island are mostly dolerite. Mount Wellington above Hobart is an example, showing distinct columns known as the Organ Pipes
Tasmania
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Tasmania from space
Tasmania
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Flag
Tasmania
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Tessellated pavement, a rare rock formation on the
Tasman Peninsula
Tasmania
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Autumn on the
Derwent River in Tasmania
24.
Andes
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The Andes or Andean Mountains are the longest continental mountain range in the world. They are a range of highlands along the western edge of South America. This range is about 7,000 km long, about 200 to 700 km wide, the Andes extend from north to south through seven South American countries, Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina and Chile. Along their length, the Andes are split into several ranges, the Andes are the location of several high plateaus – some of which host major cities, such as Quito, Bogotá, Arequipa, Medellín, Sucre, Mérida and La Paz. The Altiplano plateau is the worlds second-highest after the Tibetan plateau and these ranges are in turn grouped into three major divisions based on climate, the Tropical Andes, the Dry Andes, and the Wet Andes. The Andes are the worlds highest mountain range outside of Asia, the highest mountain outside Asia, Mount Aconcagua, rises to an elevation of about 6,961 m above sea level. The peak of Chimborazo in the Ecuadorean Andes is farther from the Earths center than any other location on the Earths surface, the worlds highest volcanoes are in the Andes, including Ojos del Salado on the Chile-Argentina border, which rises to 6,893 m. The etymology of the word Andes has been debated, the majority consensus is that it derives from the Quechua word anti, which means east as in Antisuyu, one of the four regions of the Inca Empire. In the northern part of the Andes, the isolated Sierra Nevada de Santa Marta range is considered to be part of the Andes. The term cordillera comes from the Spanish word cordel, meaning rope, the Andes range is about 200 km wide throughout its length, except in the Bolivian flexure where it is about 640 kilometres wide. The Andes are the result of plate tectonics processes, caused by the subduction of oceanic crust beneath the South American plate. The main cause of the rise of the Andes is the compression of the rim of the South American Plate due to the subduction of the Nazca Plate. In the south, the Andes share a boundary with the former Patagonia Terrane. To the west, the Andes end at the Pacific Ocean, from a geographical approach, the Andes are considered to have their western boundaries marked by the appearance of coastal lowlands and a less rugged topography. The Andes Mountains also contain large quantities of iron ore located in mountains within the range. The Andean orogen has a series of bends or oroclines, the Bolivian Orocline is a seaward concave bending in the coast of South America and the Andes Mountains at about 18° S. At this point the orientation of the Andes turns from Northwest in Peru to South in Chile, the Andean segment north and south of the orocline have been rotated 15° to 20° counter clockwise and clockwise respectively. The Bolivian Orocline area overlaps with the area of maximum width of the Altiplano Plateau, the specific point at 18° S where the coastline bends is known as the Arica Elbow
Andes
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Aerial photo of a portion of the Andes between
Argentina and
Chile
Andes
Andes
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"
Cono de Arita " in the
Puna de Atacama,
Salta (
Argentina).
Andes
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Aerial view of Aconcagua.
25.
Pacific Ocean
–
The Pacific Ocean is the largest and deepest of the Earths oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bounded by Asia and Australia in the west, the Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres. Both the center of the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean, the oceans current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favourable winds on reaching the ocean. He called it Mar Pacífico, which in both Portuguese and Spanish means peaceful sea, important human migrations occurred in the Pacific in prehistoric times. Long-distance trade developed all along the coast from Mozambique to Japan, trade, and therefore knowledge, extended to the Indonesian islands but apparently not Australia. By at least 878 when there was a significant Islamic settlement in Canton much of trade was controlled by Arabs or Muslims. In 219 BC Xu Fu sailed out into the Pacific searching for the elixir of immortality, from 1404 to 1433 Zheng He led expeditions into the Indian Ocean. The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and he named it Mar del Sur because the ocean was to the south of the coast of the isthmus where he first observed the Pacific. Later, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Castilian expedition of world circumnavigation starting in 1519, Magellan called the ocean Pacífico because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters. The ocean was often called the Sea of Magellan in his honor until the eighteenth century, sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, and Papua New Guinea. In 1542–43 the Portuguese also reached Japan, in 1564, five Spanish ships consisting of 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi and sailed to the Philippines and Mariana Islands. The Manila galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history, Spanish expeditions also discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, and the Admiralty Islands in the South Pacific. In the 16th and 17th century Spain considered the Pacific Ocean a Mare clausum—a sea closed to other naval powers, as the only known entrance from the Atlantic the Strait of Magellan was at times patrolled by fleets sent to prevent entrance of non-Spanish ships. On the western end of the Pacific Ocean the Dutch threatened the Spanish Philippines, Spain also sent expeditions to the Pacific Northwest reaching Vancouver Island in southern Canada, and Alaska. The French explored and settled Polynesia, and the British made three voyages with James Cook to the South Pacific and Australia, Hawaii, and the North American Pacific Northwest, one of the earliest voyages of scientific exploration was organized by Spain in the Malaspina Expedition of 1789–1794. It sailed vast areas of the Pacific, from Cape Horn to Alaska, Guam and the Philippines, New Zealand, Australia, and the South Pacific. Growing imperialism during the 19th century resulted in the occupation of much of Oceania by other European powers, and later, Japan, in Oceania, France got a leading position as imperial power after making Tahiti and New Caledonia protectorates in 1842 and 1853 respectively. After navy visits to Easter Island in 1875 and 1887, Chilean navy officer Policarpo Toro managed to negotiate an incorporation of the island into Chile with native Rapanui in 1888, by occupying Easter Island, Chile joined the imperial nations
Pacific Ocean
–
Maris Pacifici by
Ortelius (1589). One of the first printed maps to show the Pacific Ocean; see also
Waldseemüller map (1507).
Pacific Ocean
–
The Pacific Ocean
Pacific Ocean
–
USS
Lexington under air attack on 8 May 1942 during the
Battle of the Coral Sea
Pacific Ocean
–
Map of the Pacific Ocean during European Exploration, circa 1702–1707.
26.
Northwestern United States
–
The Northwestern United States is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, and Idaho—and usually Montana, some sources include southeast Alaska in the Northwest. The related but distinct term Pacific Northwest generally excludes areas from the Rockies eastward, the Northwestern United States is a subportion of the Western United States. In contrast, states included in the regions and Utah are not simultaneously considered part of both regions. Like the southwestern United States, the Northwest definition has moved westward over time, the current area includes the old Oregon Territory. The region is similar to Federal Region X, which comprises Oregon, Washington, Idaho and it is home to over 14.2 million citizens. As the US westward expansion, the western border also shifted westward. In the early years of the United States, newly colonized lands lying immediately west of the Allegheny Mountains were detached from Virginia, during the decades that followed, the Northwest Territory covered much of the Great Lakes region east of the Mississippi River. Together, these states have a population of 14,273,965. The largest cities and metropolitan areas in the Northwest are, Lavender, land of Giants, The Drive to the Pacific Northwest, 1750-1950 online Schwantes, Carlos. The Pacific Northwest, An Interpretive History online Warren, Sidney, farthest Frontier, The Pacific Northwest online Winther, Oscar Osburn
Northwestern United States
–
Seattle, the largest metropolitan area in the Northwest
Northwestern United States
–
The dark red states are almost always included, while the striped states are usually considered part of the Northwestern United States as well.
Northwestern United States
–
Portland, the second largest metropolitan area in the Northwest
Northwestern United States
–
Boise, the third largest metropolitan area in the Northwest
27.
Washington (state)
–
It was admitted to the Union as the 42nd state in 1889. Washington is sometimes referred to as Washington State or the State of Washington to distinguish it from Washington, Washington is the 18th largest state with an area of 71,362 square miles, and the 13th most populous state with over 7 million people. Washington is the second most populous state on the West Coast and in the Western United States, Mount Rainier, an active stratovolcano, is the states highest elevation at almost 14,411 feet and is the most topographically prominent mountain in the contiguous United States. Washington is a leading lumber producer and its rugged surface is rich in stands of Douglas fir, hemlock, ponderosa pine, white pine, spruce, larch, and cedar. Manufacturing industries in Washington include aircraft and missiles, shipbuilding and other equipment, lumber, food processing, metals and metal products, chemicals. Washington has over 1,000 dams, including the Grand Coulee Dam, built for a variety of purposes including irrigation, power, flood control, Washington was named after President George Washington by an act of the United States Congress during the creation of Washington Territory in 1853. Washington is the only U. S. state named after a president, confusion over the state of Washington and the city of Washington, D. C. led to renaming proposals during the statehood process for Washington in 1889, which failed to garner support. Washington, D. C. s own statehood movement in the 21st century includes a proposal to use the name State of Washington, Douglass Commonwealth, which would conflict with the current state of Washington. To distinguish it from the capital, Washington is sometimes referred to as Washington state, or, in more formal contexts. Residents of Washington and the Pacific Northwest simply refer to the state as Washington, Washington is the northwestern-most state of the contiguous United States. Washington is bordered by Oregon to the south, with the Columbia River forming the western part, to the west of Washington lies the Pacific Ocean. The high mountains of the Cascade Range run north-south, bisecting the state, from the Cascade Mountains westward, Western Washington has a mostly marine west coast climate, with mild temperatures and wet winters, autumns and springs, and relatively dry summers. The Cascade Range contains several volcanoes, which reach altitudes significantly higher than the rest of the mountains, from the north to the south, these major volcanoes are Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams. Mount Rainier, the tallest mountain in the state, is 50 miles south of the city of Seattle and it is also covered with more glacial ice than any other peak in the contiguous 48 states. Western Washington also is home of the Olympic Mountains, far west on the Olympic Peninsula and these deep forests, such as the Hoh Rainforest, are among the only temperate rainforests in the continental United States. Eastern Washington – the part of the state east of the Cascades – has a dry climate. It includes large areas of steppe and a few truly arid deserts lying in the rain shadow of the Cascades. Farther east, the climate becomes less arid, with annual rainfall increasing as one goes east to 21.2 inches in Pullman, the Okanogan Highlands and the rugged Kettle River Range and Selkirk Mountains cover much of the northeastern quadrant of the state
Washington (state)
–
South Eastern Washington
Washington (state)
–
Flag
Washington (state)
–
The Pacific Coast of
Westport, Washington
Washington (state)
–
Cascade Pass in the
North Cascades National Park
28.
British Columbia
–
British Columbia is the westernmost province of Canada, with a population of more than four million people located between the Pacific Ocean and the Rocky Mountains. British Columbia is also a component of the Pacific Northwest and the Cascadia bioregion, along with the U. S. states of Idaho, Oregon, Washington and Alaska. The first British settlement in the area was Fort Victoria, established in 1843, subsequently, on the mainland, the Colony of British Columbia was founded by Richard Clement Moody and the Royal Engineers, Columbia Detachment, in response to the Fraser Canyon Gold Rush. Port Moody is named after him, in 1866, Vancouver Island became part of the colony of British Columbia, and Victoria became the united colonys capital. In 1871, British Columbia became the province of Canada. Its Latin motto is Splendor sine occasu, the capital of British Columbia remains Victoria, the fifteenth-largest metropolitan region in Canada, named for the Queen who created the original European colonies. The largest city is Vancouver, the third-largest metropolitan area in Canada, the largest in Western Canada, in October 2013, British Columbia had an estimated population of 4,606,371. British Columbia evolved from British possessions that were established in what is now British Columbia by 1871, First Nations, the original inhabitants of the land, have a history of at least 10,000 years in the area. Today there are few treaties and the question of Aboriginal Title, notably, the Tsilhqotin Nation has established Aboriginal title to a portion of their territory, as a result of the recent Supreme Court of Canada decision. BCs economy is diverse, with service producing industries accounting for the largest portion of the provinces GDP and it is the endpoint of transcontinental railways, and the site of major Pacific ports that enable international trade. Though less than 5% of its vast 944,735 km2 land is arable and its climate encourages outdoor recreation and tourism, though its economic mainstay has long been resource extraction, principally logging, farming, and mining. Vancouver, the provinces largest city and metropolitan area, also serves as the headquarters of many western-based natural resource companies and it also benefits from a strong housing market and a per capita income well above the national average. The Northern Interior region has a climate with very cold winters. The climate of Vancouver is by far the mildest winter climate of the major Canadian cities, the provinces name was chosen by Queen Victoria, when the Colony of British Columbia, i. e. the Mainland, became a British colony in 1858. The current southern border of British Columbia was established by the 1846 Oregon Treaty, British Columbias land area is 944,735 square kilometres. British Columbias rugged coastline stretches for more than 27,000 kilometres and it is the only province in Canada that borders the Pacific Ocean. British Columbias capital is Victoria, located at the tip of Vancouver Island. Only a narrow strip of the Island, from Campbell River to Victoria, is significantly populated, much of the western part of Vancouver Island and the rest of the coast is covered by thick, tall and sometimes impenetrable temperate rainforest
British Columbia
–
Strait of Georgia, near
Vancouver.
British Columbia
–
Flag
British Columbia
–
The Okanagan region has a climate suitable to vineyards.
British Columbia
–
Mount Robson,
Canadian Rockies, BC
29.
Alaska
–
Alaska is a U. S. state located in the northwest extremity of North America. To the north are the Chukchi and Beaufort seas–the southern parts of the Arctic Ocean, the Pacific Ocean lies to the south and southwest. Alaska is the largest state in the United States by area, the 3rd least populous, approximately half of Alaskas residents live within the Anchorage metropolitan area. Alaskas economy is dominated by the fishing, natural gas, military bases and tourism are also a significant part of the economy. The United States purchased Alaska from the Russian Empire on March 30,1867, the area went through several administrative changes before becoming organized as a territory on May 11,1912. It was admitted as the 49th state of the U. S. on January 3,1959, the name Alaska was introduced in the Russian colonial period when it was used to refer to the peninsula. It was derived from an Aleut, or Unangam idiom, which refers to the mainland of Alaska. Literally, it means object to which the action of the sea is directed, Alaska is the northernmost and westernmost state in the United States and has the most easterly longitude in the United States because the Aleutian Islands extend into the Eastern Hemisphere. Alaska is the only non-contiguous U. S. state on continental North America and it is technically part of the continental U. S. but is sometimes not included in colloquial use, Alaska is not part of the contiguous U. S. often called the Lower 48. The capital city, Juneau, is situated on the mainland of the North American continent but is not connected by road to the rest of the North American highway system. Alaskas territorial waters touch Russias territorial waters in the Bering Strait, as the Russian Big Diomede Island, Alaska has a longer coastline than all the other U. S. states combined. Alaska is the largest state in the United States by total area at 663,268 square miles, over twice the size of Texas, Alaska is larger than all but 18 sovereign countries. Counting territorial waters, Alaska is larger than the area of the next three largest states, Texas, California, and Montana. It is also larger than the area of the 22 smallest U. S. states. Also referred to as the Panhandle or Inside Passage, this is the region of Alaska closest to the rest of the United States, as such, this was where most of the initial non-indigenous settlement occurred in the years following the Alaska Purchase. The region is dominated by the Alexander Archipelago as well as the Tongass National Forest and it contains the state capital Juneau, the former capital Sitka, and Ketchikan, at one time Alaskas largest city. The Alaska Marine Highway provides a vital transportation link throughout the area. The Interior is the largest region of Alaska, much of it is uninhabited wilderness, Fairbanks is the only large city in the region
Alaska
–
Denali is the highest peak in North America.
Alaska
–
Flag
Alaska
–
Grizzly bear fishing for
salmon at
Brooks Falls, part of
Katmai National Park and Preserve.
Alaska
–
Augustine Volcano erupting on January 12, 2006
30.
Mountain
–
A mountain is a large landform that stretches above the surrounding land in a limited area, usually in the form of a peak. A mountain is steeper than a hill. Mountains are formed through tectonic forces or volcanism and these forces can locally raise the surface of the earth. Mountains erode slowly through the action of rivers, weather conditions, a few mountains are isolated summits, but most occur in huge mountain ranges. High elevations on mountains produce colder climates than at sea level and these colder climates strongly 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, 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, volume, relief, steepness, spacing and continuity have been used as criteria for defining a mountain, whether a landform is called a mountain may depend on local usage. The highest point in San Francisco, California, is called Mount Davidson, notwithstanding its height of 300 m, similarly, Mount Scott outside Lawton, Oklahoma is only 251 m from its base to its highest point. Whittows Dictionary of Physical Geography states Some authorities regard eminences above 600 metres as mountains, in addition, some definitions also include a topographical prominence requirement, typically 100 or 500 feet. For a while, the US defined a mountain as being 1,000 feet or taller, any similar landform lower than this height was considered a hill. However, today, the United States Geological Survey concludes that these terms do not have technical definitions in the US, using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, and 14% of Africa. As a whole, 24% of the Earths land mass is mountainous, there are three main types of mountains, volcanic, fold, and block. All three types are formed from plate tectonics, when portions of the Earths crust move, crumple, 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 higher and steeper, major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity. Volcanoes are formed when a plate is pushed below another plate, at a depth of around 100 km, melting occurs in rock above the slab, and forms magma that reaches the surface. When the magma reaches the surface, it builds a volcanic mountain. Examples of volcanoes include Mount Fuji in Japan and 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
Mountain
–
Mount Everest, the highest peak on Earth
Mountain
–
Chimborazo,
Ecuador. The point on Earth's surface farthest from its center.
Mountain
–
Aiguille du Dru in the
French Alps
Mountain
–
The
Matterhorn,
Swiss Alps
31.
Storm
–
A storm is any disturbed state of an environment or astronomical bodys atmosphere especially affecting its surface, and strongly implying severe weather. Heavy snowfall can allow special recreational activities to take place which would not be possible otherwise, the English word comes from Proto-Germanic *sturmaz meaning noise, tumult. Storms are created when a center of low pressure develops with a system of high pressure surrounding it and this combination of opposing forces can create winds and result in the formation of storm clouds, such as the cumulonimbus. Small localized areas of low pressure can form from hot air rising off hot ground, resulting in smaller disturbances such as dust devils, There are many varieties and names for storms, Ice storm — Ice storms are one of the most dangerous forms of winter storms. When surface temperatures are below freezing, but a layer of above-freezing air remains aloft, rain can fall into the freezing layer. In general,8 millimetres of accumulation is all that is required, especially in combination with breezy conditions, Ice storms also make unheated road surfaces too slick to drive upon. Ice storms can vary in range from hours to days and can cripple small towns. Blizzard — There are varying definitions for blizzards, both time and by location. In general, a blizzard is accompanied by winds, heavy snow. Snow storms, especially ones with a liquid equivalent and breezy conditions, can down tree limbs, cut off power. Ocean Storm — Storm conditions out at sea are defined as having sustained winds of 48 knots or greater, usually just referred to as a storm, these systems can sink vessels of all types and sizes. Firestorm — Firestorms are conflagrations which attain such intensity that they create and it is most commonly a natural phenomenon, created during some of the largest bushfires, forest fires, and wildfires. The Peshtigo Fire is one example of a firestorm, Firestorms can also be deliberate effects of targeted explosives such as occurred as a result of the aerial bombings of Dresden. Nuclear detonations generate firestorms if high winds are not present, dust devil — a small, localized updraft of rising air. Wind storm— A storm marked by high wind with little or no precipitation, windstorm damage often opens the door for massive amounts of water and debris to cause further damage to a structure. European windstorms and derechos are two type of windstorms, high wind is also the cause of sandstorms in dry climates. Squall — sudden onset of wind increase of at least 16 knots or greater sustained for at least one minute, gale — An extratropical storm with sustained winds between 34-48 knots. Thunderstorm — A thunderstorm is a type of storm that generates lightning and it is normally accompanied by heavy precipitation
Storm
–
A
shelf cloud associated with a heavy or severe
thunderstorm over
Enschede,
Netherlands.
Storm
–
Desert storms are often accompanied by violent winds, and pass rapidly.
Storm
–
Satellite image of the intense
nor'easter responsible for the
North American blizzard of 2006. Note the
hurricane -like eye at the center.
Storm
–
Classic storm of summer, in
Sierras de Córdoba,
Argentina.
32.
Twilight
–
Twilight is the illumination of the Earths lower atmosphere when the Sun itself is not directly visible because it is below the horizon. Twilight is produced by scattering in the upper atmosphere, illuminating the lower atmosphere so that the surface of the Earth is neither completely lit nor completely dark. The word twilight is also used to denote the periods of time when this illumination occurs, the further the Sun is below the horizon, the dimmer the twilight. When the Sun reaches 18 degrees below the horizon, the brightness is nearly zero. When the Sun again reaches 18 degrees below the horizon, nighttime becomes morning twilight, Twilight should not be confused with auroras, which can have a similar appearance in the night sky at high latitudes. By analogy with evening twilight, the word twilight is also used metaphorically, to imply that something is losing strength. For example, very old people may be said to be in the twilight of their lives, the collateral adjective for twilight is crepuscular which is sometimes applied to insects, fish, and mammals that are most active during that time. Twilight is defined according to the elevation angle θs, which is the position of the geometric center of the sun relative to the horizon. There are three established and widely accepted subcategories of twilight, civil twilight, nautical twilight, and astronomical twilight. Morning civil twilight begins when the center of the sun is 6° below the horizon. Evening civil twilight begins at sunset or when the center of the sun is 0°50′ below the horizon. In the United States military, the initialisms BMCT and EECT are used to refer to these periods, morning nautical twilight begins and evening nautical twilight ends when the geometric center of the sun reaches 12° below the horizon. Morning astronomical twilight begins and Evening astronomical twilight ends when the center of the Sun reaches 18° below the horizon. There are three established and widely accepted subcategories of twilight, civil twilight, nautical twilight, and astronomical twilight, under clear weather conditions, civil twilight approximates the limit at which solar illumination suffices for the human eye to clearly distinguish terrestrial objects. Enough sunlight renders artificial sources unnecessary for most outdoor activities, at civil dawn, the beginning of morning civil twilight, and at civil dusk, the end of evening civil twilight, sunlight clearly defines the horizon while the brightest stars and planets can appear. As observed from the Earth, sky-gazers know Venus, the brightest planet, law-makers have enshrined the concept of civil twilight. Such statutes typically use a period after sunset or before sunrise. The period may affect when pilots require a rating to fly aircraft
Twilight
–
Twilight at
Baker Beach
Twilight
–
Twilight is the time between
dawn and
sunrise, or between
sunset and
dusk.
Twilight
–
During nautical twilight, the horizon is clearly visible, but artificial lighting must be used to see terrestrial objects clearly.
Twilight
–
American Benedictine monks around an
Easter fire preparing to light the
Paschal candle prior to Easter Vigil
mass
33.
Tornado
–
A tornado is a rapidly rotating column of air that spins while in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. Most tornadoes have wind speeds less than 110 miles per hour, are about 250 feet across, the most extreme tornadoes can attain wind speeds of more than 300 miles per hour, are more than two miles in diameter, and stay on the ground for dozens of miles. Various types of tornadoes include the multiple vortex tornado, landspout and waterspout, waterspouts are characterized by a spiraling funnel-shaped wind current, connecting to a large cumulus or cumulonimbus cloud. They are generally classified as non-supercellular tornadoes that develop over bodies of water and these spiraling columns of air frequently develop in tropical areas close to the equator, and are less common at high latitudes. Other tornado-like phenomena that exist in nature include the gustnado, dust devil, fire whirls, downbursts are frequently confused with tornadoes, though their action is dissimilar. Tornadoes have been observed and documented on every continent except Antarctica, however, the vast majority of tornadoes occur in the Tornado Alley region of the United States, although they can occur nearly anywhere in North America. There are several scales for rating the strength of tornadoes, the Fujita scale rates tornadoes by damage caused and has been replaced in some countries by the updated Enhanced Fujita Scale. An F0 or EF0 tornado, the weakest category, damages trees, an F5 or EF5 tornado, the strongest category, rips buildings off their foundations and can deform large skyscrapers. The similar TORRO scale ranges from a T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes, Doppler radar data, photogrammetry, and ground swirl patterns may also be analyzed to determine intensity and assign a rating. The word tornado is a form of the Spanish word tronada. This in turn was taken from the Latin tonare, meaning to thunder and it most likely reached its present form through a combination of the Spanish tronada and tornar, however, this may be a folk etymology. A tornado is also referred to as a twister, and is also sometimes referred to by the old-fashioned colloquial term cyclone. The term cyclone is used as a synonym for tornado in the often-aired 1939 film The Wizard of Oz, the term twister is also used in that film, along with being the title of the 1996 tornado-related film Twister. A tornado is a rotating column of air, in contact with the ground, either pendant from a cumuliform cloud or underneath a cumuliform cloud. For a vortex to be classified as a tornado, it must be in contact with both the ground and the cloud base. Scientists have not yet created a definition of the word, for example. Tornado refers to the vortex of wind, not the condensation cloud and this results in the formation of a visible funnel cloud or condensation funnel. There is some disagreement over the definition of cloud and condensation funnel
Tornado
–
A tornado near
Anadarko, Oklahoma. The funnel is the thin tube reaching from the cloud to the ground. The lower part of this tornado is surrounded by a
translucent dust cloud, kicked up by the tornado's strong winds at the surface. The wind of the tornado has a much wider radius than the funnel itself.
Tornado
–
A tornado near
Seymour, Texas 1987
Tornado
–
This tornado has no funnel cloud; however, the rotating dust cloud indicates that strong winds are occurring at the surface, and thus it is a true tornado.
Tornado
–
A wedge tornado, nearly a mile wide, which hit
Binger, Oklahoma in 1981
34.
Ski country
–
Ski country is the hilly, snowy portions of the boundary between the Niagara Frontier and the Southern Tier of the western part of New York. The result of this is that through orographic lift, a significant amount of lake effect snow falls there during the months of November, December, the portion of ski country in Western New York is defined by a geologic formation known as the Chautauqua Ridge. As the name implies, the area is popular with skiers. The local ski resorts primarily offer alpine skiing while the state parks use their hiking trails for cross-country skiing. Operated from 1951 until New Yorks ongoing eminent domain campaign forced most of Red Houses private property to be vacated in 1972, bluemont Ski Area - Yorkshire, New York - closed in 1982 Bova Ski Resort - in Red House, New York. Bova was the site of a Great Depression-era public works project as part of Allegany State Park that would serve as the areas first ski destination, the Bova resort also included the regions only ski jumps. The ski jumps were damaged by a mudslide in 1979, and outdated and it closed after several decades of operation due to competition from other, newer resorts in the area
Ski country
–
The eastern half of the maroon portions on this map is the approximate reach of ski country in New York and Pennsylvania.
35.
New York (state)
–
New York is a state in the northeastern United States, and is the 27th-most extensive, fourth-most populous, and seventh-most densely populated U. S. state. New York is bordered by New Jersey and Pennsylvania to the south and Connecticut, Massachusetts, and Vermont to the east. With an estimated population of 8.55 million in 2015, New York City is the most populous city in the United States, the New York Metropolitan Area is one of the most populous urban agglomerations in the world. New York City makes up over 40% of the population of New York State, two-thirds of the states population lives in the New York City Metropolitan Area, and nearly 40% lives on Long Island. Both the state and New York City were named for the 17th-century Duke of York, the next four most populous cities in the state are Buffalo, Rochester, Yonkers, and Syracuse, while the state capital is Albany. New York has a diverse geography and these more mountainous regions are bisected by two major river valleys—the north-south Hudson River Valley and the east-west Mohawk River Valley, which forms the core of the Erie Canal. Western New York is considered part of the Great Lakes Region and straddles Lake Ontario, between the two lakes lies Niagara Falls. The central part of the state is dominated by the Finger Lakes, New York had been inhabited by tribes of Algonquian and Iroquoian-speaking Native Americans for several hundred years by the time the earliest Europeans came to New York. The first Europeans to arrive were French colonists and Jesuit missionaries who arrived southward from settlements at Montreal for trade, the British annexed the colony from the Dutch in 1664. The borders of the British colony, the Province of New York, were similar to those of the present-day state, New York is home to the Statue of Liberty, a symbol of the United States and its ideals of freedom, democracy, and opportunity. In the 21st century, New York has emerged as a node of creativity and entrepreneurship, social tolerance. On April 17,1524 Verrazanno entered New York Bay, by way of the now called the Narrows into the northern bay which he named Santa Margherita. Verrazzano described it as a vast coastline with a delta in which every kind of ship could pass and he adds. This vast sheet of water swarmed with native boats and he landed on the tip of Manhattan and possibly on the furthest point of Long Island. Verrazannos stay was interrupted by a storm which pushed him north towards Marthas Vineyard, in 1540 French traders from New France built a chateau on Castle Island, within present-day Albany, due to flooding, it was abandoned the next year. In 1614, the Dutch under the command of Hendrick Corstiaensen, rebuilt the French chateau, Fort Nassau was the first Dutch settlement in North America, and was located along the Hudson River, also within present-day Albany. The small fort served as a trading post and warehouse, located on the Hudson River flood plain, the rudimentary fort was washed away by flooding in 1617, and abandoned for good after Fort Orange was built nearby in 1623. Henry Hudsons 1609 voyage marked the beginning of European involvement with the area, sailing for the Dutch East India Company and looking for a passage to Asia, he entered the Upper New York Bay on September 11 of that year
New York (state)
–
British general
John Burgoyne surrenders at
Saratoga in 1777.
New York (state)
–
Flag
New York (state)
–
1800 map of New York from
Low's Encyclopaedia
New York (state)
–
The
Erie Canal at
Lockport, New York in 1839
36.
Pennsylvania
–
Pennsylvania /ˌpɛnsᵻlˈveɪnjə/, officially the Commonwealth of Pennsylvania, is a state located in the northeastern and Mid-Atlantic regions of the United States. The Appalachian Mountains run through its middle, Pennsylvania is the 33rd largest, the 5th most populous, and the 9th most densely populated of the 50 United States. The states five most populous cities are Philadelphia, Pittsburgh, Allentown, Erie, the state capital, and its ninth-largest city, is Harrisburg. Pennsylvania has 140 miles of shoreline along Lake Erie and the Delaware Estuary. The state is one of the 13 original founding states of the United States, it came into being in 1681 as a result of a land grant to William Penn. Part of Pennsylvania, together with the present State of Delaware, had earlier been organized as the Colony of New Sweden and it was the second state to ratify the United States Constitution, on December 12,1787. Independence Hall, where the United States Declaration of Independence and United States Constitution were drafted, is located in the states largest city of Philadelphia, during the American Civil War, the Battle of Gettysburg, was fought in the south central region of the state. Valley Forge near Philadelphia was General Washingtons headquarters during the winter of 1777–78. Pennsylvania is 170 miles north to south and 283 miles east to west, of a total 46,055 square miles,44,817 square miles are land,490 square miles are inland waters, and 749 square miles are waters in Lake Erie. It is the 33rd largest state in the United States, Pennsylvania has 51 miles of coastline along Lake Erie and 57 miles of shoreline along the Delaware Estuary. Cities include Philadelphia, Reading, Lebanon and Lancaster in the southeast, Pittsburgh in the southwest, the tri-cities of Allentown, Bethlehem, the northeast includes the former anthracite coal mining communities of Scranton, Wilkes-Barre, Pittston City, and Hazleton. Erie is located in the northwest, the state has 5 regions, namely the Allegheny Plateau, Ridge and Valley, Atlantic Coastal Plain, Piedmont, and the Erie Plain. Straddling two major zones, the majority of the state, with the exception of the corner, has a humid continental climate. The largest city, Philadelphia, has characteristics of the humid subtropical climate that covers much of Delaware. Moving toward the interior of the state, the winter climate becomes colder, the number of cloudy days increase. Western areas of the state, particularly locations near Lake Erie, can receive over 100 inches of snowfall annually, the state may be subject to severe weather from spring through summer into fall. Tornadoes occur annually in the state, sometimes in large numbers, the Tuscarora Nation took up temporary residence in the central portion of Pennsylvania ca. Both the Dutch and the English claimed both sides of the Delaware River as part of their lands in America
Pennsylvania
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World's End State Park, Sullivan County
Pennsylvania
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Flag
Pennsylvania
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Autumn in North Branch Township,
Wyoming County, Pennsylvania
Pennsylvania
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Penn's Treaty with the Indians, by
Edward Hicks
37.
Lake effect snow
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The same effect also occurs over bodies of salt water, when it is termed ocean-effect or bay-effect snow. The effect is enhanced when the air mass is uplifted by the orographic influence of higher elevations on the downwind shores. This uplifting can produce narrow but very intense bands of precipitation, the areas affected by lake-effect snow are called snowbelts. A lake-effect blizzard is the blizzard-like conditions resulting from lake-effect snow, if the air temperature is low enough to keep the precipitation frozen, it falls as lake-effect snow. For lake-effect rain or snow to form, the air moving across the lake must be significantly cooler than the surface air. Specifically, the air temperature at an altitude where the air pressure is 850 millibars should be 13 °C lower than the temperature of the air at the surface. Lake-effect occurring when the air at 850 millibars is much colder than the surface can produce thundersnow, snow showers accompanied by lightning. A temperature difference of 13 °C between the temperature and the height in the atmosphere provides for absolute instability and allows vigorous heat. The distance that an air mass travels over a body of water is called fetch, because most lakes are irregular in shape, different angular degrees of travel will yield different distances, typically a fetch of at least 100 km is required to produce lake effect precipitation. Generally, the larger the fetch the more precipitation that will be produced, larger fetches provide the boundary layer with more time to become saturated with water vapor and for heat energy to move from the water to the air. If directional shear between the surface and the height in the atmosphere at which the pressure measures 700 mb is greater than 60 degrees. If the directional shear between the body of water and the height at which the pressure measures 700 mb is between 30 and 60 degrees, weak lake-effect bands are possible. In environments where the shear is less than 30 degrees, strong, speed shear is less critical, but should be relatively uniform. However, assuming the surface to 700 mb winds are uniform, an overall velocity will work to transport moisture quicker from the water. A lower upstream relative humidity will make it difficult and time consuming for lake effect condensation, clouds. The opposite is true if the moisture has a high relative humidity, allowing lake effect condensation, cloud and precipitation to form more readily. Any large body of water upwind will impact lake-effect precipitation to the lee of a lake by adding moisture or pre-existing lake-effect bands. Upwind lakes do not always lead to an increase of precipitation downwind, vorticity advection aloft and large upscale ascent help increase mixing and the convective depth, while cold air advection lowers the temperature and increases instability
Lake effect snow
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Cold northwesterly wind over Great Lakes Superior and Michigan created the lake-effect snowfall of December 5, 2000.
Lake effect snow
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Buffalo, New York, after 82.3 inches (209 cm) of snow fell from December 24, 2001 to December 28, 2001
Lake effect snow
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Fulton, New York after a snowburst dropped 4–6 feet (122–183 cm) of snow over most of Oswego County January 28–31, 2004.
Lake effect snow
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The Veteran's Day storm of November 9–14, 1996 may be the most severe early season lake effect snow (LES) storm the Great Lakes has witnessed in the past fifty years. At the height of the storm, over 160,000 customers were without power in Greater Cleveland alone, as the storm produced isolated snowfall tallies approaching 70 inches (178 cm).
38.
Transylvania County, North Carolina
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Transylvania County is a county located in the U. S. state of North Carolina. As of the 2010 census, the population was 33,090, Transylvania County comprises the Brevard, NC Micropolitan Statistical Area, which is also included in the Asheville-Brevard, NC CSA combined statistical area. Founded in 1861, the name is derived from the colonial Transylvania Company and has Latin origins, trans. Prior to the twentieth century, an overwhelming majority of Transylvania County’s residents subsisted through agriculture, often growing basic staples such as potatoes. In the 1930s, Harry Straus opened a mill in the Pisgah Forest area. During the peak years of the 1950s, DuPont located one of its factories in the county. Since that time, the county has worked to reshape its economy around the growing Appalachian summer and winter tourism industry. According to the U. S. Census Bureau, the county has an area of 381 square miles. There are over 250 waterfalls in the county, receiving over 90 inches of rain annually, Transylvania County is the wettest county in the state. This is contrasted with Buncombe County, which is thirty miles northeast of Transylvania County receiving the lowest precipitation, the Blue Ridge Parkway traverses through parts of the county, affording spectacular views of the Appalachian Mountains, which reach over 6,000 feet elevation in the county. The highest point, Chestnut Knob,6,025 feet, the population density was 83 people per square mile. There were 15,553 housing units at a density of 41 per square mile. The racial makeup of the county was 92. 4% White,3. 9% Black or African American,0. 3% Native American,0. 4% Asian,2. 9% of the population were Hispanic or Latino of any race. 26. 10% of all households were made up of individuals and 12. 40% had someone living alone who was 65 years of age or older, the average household size was 2.30 and the average family size was 2.74. In the county, the population was out with 20. 40% under the age of 18,8. 20% from 18 to 24,23. 10% from 25 to 44,26. 90% from 45 to 64. The median age was 44 years, for every 100 females there were 92.70 males. For every 100 females age 18 and over, there were 89.50 males, the median income for a household in the county was $38,587, and the median income for a family was $45,579. Males had an income of $31,743 versus $21,191 for females
Transylvania County, North Carolina
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Transylvania County Courthouse
Transylvania County, North Carolina
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Seal
Transylvania County, North Carolina
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The
Biltmore School of Forestry, founded in 1898, was the nation's first forestry school.
Transylvania County, North Carolina
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Looking Glass Falls
39.
Appalachian Mountains
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The Appalachian Mountains, often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period and it once reached elevations similar to those of the Alps and the Rocky Mountains before naturally occurring erosion. The Appalachian chain is a barrier to east-west travel, as it forms a series of alternating ridgelines, definitions vary on the precise boundaries of the Appalachians. A common variant definition does not include the Adirondack Mountains, which belong to the Grenville Orogeny and have a different geological history from the rest of the Appalachians. The range covers parts of the islands of Saint Pierre and Miquelon, the system is divided into a series of ranges, with the individual mountains averaging around 3,000 ft. The highest of the group is Mount Mitchell in North Carolina at 6,684 feet, the term Appalachian refers to several different regions associated with the mountain range. Most broadly, it refers to the mountain range with its surrounding hills. The Ouachita Mountains in Arkansas and Oklahoma were originally part of the Appalachians as well, the name was soon altered by the Spanish to Apalachee and used as a name for the tribe and region spreading well inland to the north. Pánfilo de Narváezs expedition first entered Apalachee territory on June 15,1528, now spelled Appalachian, it is the fourth-oldest surviving European place-name in the US. After the de Soto expedition in 1540, Spanish cartographers began to apply the name of the tribe to the mountains themselves. The first cartographic appearance of Apalchen is on Diego Gutierrezs map of 1562, the name was not commonly used for the whole mountain range until the late 19th century. A competing and often more popular name was the Allegheny Mountains, Alleghenies, in the early 19th century, Washington Irving proposed renaming the United States either Appalachia or Alleghania. In U. S. dialects in the regions of the Appalachians. In northern parts of the range, it is pronounced /ˌæpəˈleɪtʃᵻnz/ or /ˌæpəˈleɪʃᵻnz/, the third syllable is like lay. There is often debate between the residents of the regions as to which pronunciation is the more correct one. Elsewhere, a commonly accepted pronunciation for the adjective Appalachian is /ˌæpəˈlætʃiən/, the whole system may be divided into three great sections, Northern, The northern section runs from the Canadian province of Newfoundland and Labrador to the Hudson River. The Monteregian Hills, which cross the Green Mountains in Quebec, are also unassociated with the Appalachians, Central, The central section goes from the Hudson Valley to the New River running through Virginia and West Virginia. Southern, The southern section runs from the New River onwards and it consists of the prolongation of the Blue Ridge, which is divided into the Western Blue Ridge Front and the Eastern Blue Ridge Front, the Ridge-and-Valley Appalachians, and the Cumberland Plateau
Appalachian Mountains
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View from the slopes of
Back Allegheny Mountain, looking east; visible are
Allegheny Mountain (in the
Monongahela National Forest of
West Virginia, middle distance) and
Shenandoah Mountain (in the
George Washington National Forest of
Virginia, far distance)
Appalachian Mountains
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Detail of Diego Gutiérrez's 1562 map of the Western Hemisphere, showing the first known use of a variation of the place name "Appalachia" ("Apalchen") - from the map Americae sive qvartae orbis partis nova et exactissima descriptio
Appalachian Mountains
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Shaded relief map of the
Cumberland Plateau and
Ridge-and-Valley Appalachians on the
Virginia –
West Virginia border
Appalachian Mountains
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Old
fault exposed by roadcut near
Harrisburg,
Pennsylvania, along
Interstate 81, such faults are common in the folded Appalachians
40.
West Virginia
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West Virginia /ˌwɛst vərˈdʒɪnjə/ is a state located in the Appalachian region of the Southern United States. It is bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, Pennsylvania to the north, West Virginia is the 9th smallest by area, is ranked 38th in population, and has the second lowest household income of the 50 United States. The capital and largest city is Charleston, West Virginia was admitted to the Union on June 20,1863, and was a key Civil War border state. The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States, the unique position of West Virginia means that it is often included in several geographical regions, including the Mid-Atlantic, the Upland South, and the Southeastern United States. It is the state that is entirely within the area served by the Appalachian Regional Commission. The state is noted for its mountains and rolling hills, its historically significant logging and coal mining industries and it is one of the most densely karstic areas in the world, making it a choice area for recreational caving and scientific research. The karst lands contribute to much of the states cool trout waters and it is also known for a wide range of outdoor recreational opportunities, including skiing, whitewater rafting, fishing, hiking, backpacking, mountain biking, and hunting. Many ancient man-made earthen mounds from various mound builder cultures survive, especially in the areas of Moundsville, South Charleston. The artifacts uncovered in these give evidence of village societies and they had a tribal trade system culture that crafted cold-worked copper pieces. The Iroquois drove out other American Indian tribes from the region to reserve the upper Ohio Valley as a ground in the 1670s. Siouan language tribes such as the Moneton had also recorded in the area previously. West Virginia was originally part of the British Virginia Colony from 1607 to 1776, residents of the western and northern counties set up a separate government under Francis Pierpont in 1861, which they called the restored government. Most voted to separate from Virginia and the new state was admitted to the Union in 1863, in 1864 a state constitutional convention drafted a constitution, which was ratified by the legislature without putting it to popular vote. West Virginia abolished slavery and temporarily disfranchised men who had held Confederate office or fought for the Confederacy, West Virginias history has been profoundly affected by its mountainous terrain, numerous and vast river valleys, and rich natural resources. These were all factors driving its economy and the lifestyles of its residents, a 2010 analysis of a local stalagmite revealed that Native Americans were burning forests to clear land as early as 100 BC. Some regional late-prehistoric Eastern Woodland tribes were involved in hunting and fishing, practicing the slash. Another group progressed to the more time-consuming, advanced companion crop fields method of gardening, also continuing from ancient indigenous people of the state, field space and time was given to tobacco growing through to early historic. Maize did not make a contribution to the diet until after 1150 BP
West Virginia
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Thomas Lee, the first manager of the
Ohio Company of Virginia.
West Virginia
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Flag
West Virginia
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A celebration at a slave wedding in Virginia, 1838
West Virginia
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On October 24, 1861, when voters from 41 counties voted to form a new state, voter turnout was 34%. The name was subsequently changed from Kanawha to West Virginia.
41.
Ecoregions of Madagascar
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The ecoregions of Madagascar, as defined by the World Wildlife Fund, include seven terrestrial, five freshwater, and two marine ecoregions. Madagascars diverse natural habitats harbour a rich fauna and flora with high levels of endemism, Madagascar belongs to the Afrotropical realm. Madagascar features very contrasting topography, climate, and geology, a mountain range on the east, rising to 2,876 m at its highest point, captures most rainfall brought in by trade winds from the Indian Ocean. Consequently, the eastern belt harbours most of the humid forests, the rain shadow region in the southwest has a sub-arid climate. Temperatures are highest on the west coast, with means of up to 30 °C, while the high massifs have a cool climate. Seven terrestrial ecoregions are defined by the World Wildlife Fund for Madagascar and they range from the very humid eastern lowland forests to the sub-arid spiny thickets in the southwest. Freshwater ecoregions correspond to major catchment areas with an assemblage of species. They are divided into two ecoregions, Southeast Madagascar Western and Northern Madagascar
Ecoregions of Madagascar
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Satellite image of Madagascar
42.
Madagascar
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Madagascar, officially the Republic of Madagascar, and previously known as the Malagasy Republic, is an island country in the Indian Ocean, off the coast of Southeast Africa. The nation comprises the island of Madagascar, and numerous smaller peripheral islands, consequently, Madagascar is a biodiversity hotspot, over 90% of its wildlife is found nowhere else on Earth. The islands diverse ecosystems and unique wildlife are threatened by the encroachment of the growing human population. The first archaeological evidence for human foraging on Madagascar dates to 2000 BC, human settlement of Madagascar occurred between 350 BC and AD550 by Austronesian peoples arriving on outrigger canoes from Borneo. These were joined around AD1000 by Bantu migrants crossing the Mozambique Channel from East Africa, other groups continued to settle on Madagascar over time, each one making lasting contributions to Malagasy cultural life. The Malagasy ethnic group is divided into 18 or more sub-groups of which the largest are the Merina of the central highlands. Until the late 18th century, the island of Madagascar was ruled by an assortment of shifting sociopolitical alliances. Beginning in the early 19th century, most of the island was united and ruled as the Kingdom of Madagascar by a series of Merina nobles, the monarchy collapsed in 1897 when the island was absorbed into the French colonial empire, from which the island gained independence in 1960. The autonomous state of Madagascar has since undergone four major constitutional periods, since 1992, the nation has officially been governed as a constitutional democracy from its capital at Antananarivo. However, in an uprising in 2009, president Marc Ravalomanana was made to resign. Constitutional governance was restored in January 2014, when Hery Rajaonarimampianina was named president following a 2013 election deemed fair, Madagascar is a member of the United Nations, the Organisation Internationale de la Francophonie and the Southern African Development Community. Madagascar belongs to the group of least developed countries, according to the United Nations, Malagasy and French are both official languages of the state. The majority of the population adheres to traditional beliefs, Christianity, ecotourism and agriculture, paired with greater investments in education, health, and private enterprise, are key elements of Madagascars development strategy. As of 2017, the economy has been weakened by the 2009-2013 political crisis, in the Malagasy language, the island of Madagascar is called Madagasikara and its people are referred to as Malagasy. The islands appellation Madagascar is not of origin, but rather was popularized in the Middle Ages by Europeans. On St. Laurences Day in 1500, Portuguese explorer Diogo Dias landed on the island, polos name was preferred and popularized on Renaissance maps. At 592,800 square kilometres, Madagascar is the worlds 47th largest country, the country lies mostly between latitudes 12°S and 26°S, and longitudes 43°E and 51°E. Neighboring islands include the French territory of Réunion and the country of Mauritius to the east, as well as the state of Comoros, the nearest mainland state is Mozambique, located to the west
Madagascar
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The terraced paddy fields of the
central highlands of Madagascar (left) give way to tropical rainforest along the eastern coast (center) bordered by the shores of the
Indian Ocean (right).
Madagascar
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Flag
Madagascar
Madagascar
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The grassy plains that dominate the western landscape are dotted with stony massifs (left), patches of deciduous forest, and
baobab trees (center), while the south is characterized by desert and
spiny forests (right).
43.
Table Mountain
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Table Mountain is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa. It is a significant tourist attraction, with visitors using the cableway or hiking to the top. The mountain forms part of the Table Mountain National Park, the main feature of Table Mountain is the level plateau approximately 3 kilometres from side to side, edged by impressive cliffs. The plateau, flanked by Devils Peak to the east and by Lions Head to the west and this broad sweep of mountainous heights, together with Signal Hill, forms the natural amphitheatre of the City Bowl and Table Bay harbour. The highest point on Table Mountain is towards the end of the plateau and is marked by Maclears Beacon. It is 1,086 metres above sea level, nou en about 19 metres higher than the station at the western end of the plateau. Legend attributes this phenomenon to a smoking contest between the Devil and a pirate called Van Hunks. When the table cloth is seen, it symbolizes the contest, immediately to the south of Table Mountain is a rugged plateau at a somewhat lower elevation than the Table Mountain Plateau, called the Back Table. The Back Table extends southwards for approximately 6 km to the Constantia Nek-Hout Bay valley, the Atlantic side of the Back Table, is known as the Twelve Apostles, which extends from Kloof Nek to Hout Bay. It is better known by the names of the areas on its the lower slopes, Groote Schuur Estate, Newlands Forest, Kirstenbosch Botanical Gardens, Cecilia Forest. The upper approximately 600 m portion of the 1 km high table-topped mountain, or mesa, the Graafwater rocks can best be seen just above the contour path on the front of Table Mountain, and around Devils Peak. They can also seen in the cutting along Chapmans Peak Drive. These rocks are believed to have originated in shallow tidal flats, in which a few Ordovician fossils, the overlying TMS probably arose in deeper water, either as a result of subsidence, or a rise in the sea level. The Graafwater rocks rest on the basement consisting of Cape Granite, Devils Peak, Signal Hill, the City Bowl and much of the Cape Flats, however, rest on heavily folded and altered phyllites and hornfelses known informally as the Malmesbury shales. The Cape Granite and Malmesbury shales form the lower, gentler slopes of the Table Mountain range on the Cape Peninsula and they are of late Precambrian age, pre-dating the Graafwater rocks by at least 40 million years. The basement rocks are not nearly as resistant to weathering as the TMS, but significant outcrops of the Cape Granite are visible on the side of Lions Head. The weathered granite soil of the slopes of the Peninsula Mountain range are more fertile than the nutrient-poor soils derived from TMS. Most of the vineyards found on the Cape Peninsula are therefore found on granitic slopes of the Table Mountain range
Table Mountain
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Table Mountain
Table Mountain
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Table Mountain seen from
Lion's Head with low lying cloud cover over Cape Town.
Table Mountain
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Panorama from the top of Table Mountain. From left to right are visible
Lion's Head,
Signal Hill,
Robben Island, the
Cape Town city centre,
Table Bay, and
Devil's Peak.
Table Mountain
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Cape Peninsula and Table Mountain—
Landsat image over
SRTM Elevation. North is on the left of the image, and Table Mountain is in the foreground at the northern end of the peninsula.
44.
Cape Town
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Cape Town is a coastal city in South Africa. It is the second-most populous urban area in South Africa after Johannesburg and it is also the capital and primate city of the Western Cape province. As the seat of the Parliament of South Africa, it is also the capital of the country. It forms part of the City of Cape Town metropolitan municipality, the city is famous for its harbour, for its natural setting in the Cape Floristic Region, and for such well-known landmarks as Table Mountain and Cape Point. As of 2014, it is the 10th most populous city in Africa and it is one of the most multicultural cities in the world, reflecting its role as a major destination for immigrants and expatriates to South Africa. The city was named the World Design Capital for 2014 by the International Council of Societies of Industrial Design, in 2014, Cape Town was named the best place in the world to visit by both the American New York Times and the British Daily Telegraph. Located on the shore of Table Bay, Cape Town was first developed by the Dutch East India Company as a station for Dutch ships sailing to East Africa, India. Jan van Riebeecks arrival on 6 April 1652 established the first permanent European settlement in South Africa, Cape Town quickly outgrew its original purpose as the first European outpost at the Castle of Good Hope, becoming the economic and cultural hub of the Cape Colony. Until the Witwatersrand Gold Rush and the development of Johannesburg, Cape Town was the largest city in South Africa, the earliest known remnants in the region were found at Peers Cave in Fish Hoek and date to between 15,000 and 12,000 years ago. It was later renamed by John II of Portugal as Cape of Good Hope because of the optimism engendered by the opening of a sea route to India. Vasco da Gama recorded a sighting of the Cape of Good Hope in 1497, in the late 16th century, Portuguese, French, Danish, Dutch and English but mainly Portuguese ships regularly stopped over in Table Bay en route to the Indies. They traded tobacco, copper and iron with the Khoikhoi in exchange for fresh meat, the settlement grew slowly during this period, as it was hard to find adequate labour. This labour shortage prompted the authorities to import slaves from Indonesia, many of these became ancestors of the first Cape Coloured communities. Some of these, including grapes, cereals, ground nuts, potatoes, apples and citrus, had an important, the Dutch Republic being transformed in Revolutionary Frances vassal Batavian Republic, Great Britain moved to take control of its colonies. Britain captured Cape Town in 1795, but the Cape was returned to the Dutch by treaty in 1803, British forces occupied the Cape again in 1806 following the Battle of Blaauwberg. In the Anglo-Dutch Treaty of 1814, Cape Town was permanently ceded to Britain and it became the capital of the newly formed Cape Colony, whose territory expanded very substantially through the 1800s. With expansion came calls for independence from Britain, with the Cape attaining its own parliament. Suffrage was established according to the non-racial, but sexist Cape Qualified Franchise, the discovery of diamonds in Griqualand West in 1867, and the Witwatersrand Gold Rush in 1886, prompted a flood of immigrants to South Africa
Cape Town
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Clockwise from top: Cape Town CBD,
Strand,
Clifton beach,
Table Mountain,
Port of Cape Town,
Cape Town City Hall
Cape Town
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Coat of arms
Cape Town
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Arrival of
Jan van Riebeeck in
Table Bay by
Charles Bell
Cape Town
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View of Table Bay with ships of the
Dutch East India Company, c. 1683
45.
South Africa
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South Africa, officially the Republic of South Africa, is the southernmost country in Africa. South Africa is the 25th-largest country in the world by land area and it is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different Bantu languages, the remaining population consists of Africas largest communities of European, Asian, and multiracial ancestry. South Africa is a multiethnic society encompassing a variety of cultures, languages. Its pluralistic makeup is reflected in the recognition of 11 official languages. The country is one of the few in Africa never to have had a coup détat, however, the vast majority of black South Africans were not enfranchised until 1994. During the 20th century, the black majority sought to recover its rights from the dominant white minority, with this struggle playing a role in the countrys recent history. The National Party imposed apartheid in 1948, institutionalising previous racial segregation, since 1994, all ethnic and linguistic groups have held political representation in the countrys democracy, which comprises a parliamentary republic and nine provinces. South Africa is often referred to as the Rainbow Nation to describe the multicultural diversity. The World Bank classifies South Africa as an economy. Its economy is the second-largest in Africa, and the 34th-largest in the world, in terms of purchasing power parity, South Africa has the seventh-highest per capita income in Africa. However, poverty and inequality remain widespread, with about a quarter of the population unemployed, nevertheless, South Africa has been identified as a middle power in international affairs, and maintains significant regional influence. The name South Africa is derived from the geographic location at the southern tip of Africa. Upon formation the country was named the Union of South Africa in English, since 1961 the long form name in English has been the Republic of South Africa. In Dutch the country was named Republiek van Zuid-Afrika, replaced in 1983 by the Afrikaans Republiek van Suid-Afrika, since 1994 the Republic has had an official name in each of its 11 official languages. Mzansi, derived from the Xhosa noun umzantsi meaning south, is a name for South Africa. South Africa contains some of the oldest archaeological and human fossil sites in the world, extensive fossil remains have been recovered from a series of caves in Gauteng Province. The area is a UNESCO World Heritage site and has termed the Cradle of Humankind
South Africa
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Mapungubwe Hill, the site of the former capital of the
Kingdom of Mapungubwe
South Africa
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Flag
South Africa
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Arrival of
Jan van Riebeeck, the first European to settle in South Africa, with
Devil's Peak in the background
South Africa
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Depiction of a
Zulu attack on a Boer camp in February 1838
46.
Oppland
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Oppland is a county in Norway, bordering Sør-Trøndelag, Møre og Romsdal, Sogn og Fjordane, Buskerud, Akershus, Oslo and Hedmark. The county administration is in Lillehammer, Oppland is, together with Hedmark, one of the only two landlocked counties of Norway. Innlandet is one of several names proposed for an administrative region consisting of Hedmark. The two counties are slated to be re-merged after having split in 1781. Historically, the region was known as Opplandene. Oppland extends from the lakes Mjøsa and Randsfjorden to the mountains Dovrefjell, Jotunheimen, the county is conventionally divided into traditional districts. These are the Gudbrandsdalen, Valdres, Toten, Hadeland and Land, Oppland includes the towns Lillehammer, Gjøvik, Otta, and Fagernes, and Norways two highest mountains, Glittertind and Galdhøpiggen, Valdres and the Gudbrand Valley being popular attractions. The Gudbrand Valley surrounds the river Gudbrandsdalslågen, and includes the udes the area extending from Jotunheimen down to Bagn at Begna River and it is a well known place for skiing and winter sports. The main population centres in this area are Beitostølen and Fagernes, eight of the ten highest mountains in Norway are located in the western part of Oppland. In Norse times the inner parts of Norway were called Upplǫnd the upper countries, the first element is upp upper. The last element is lǫnd, the form of land. In 1757 the inner parts of the great Akershus amt were separated and this was divided in 1781 into Christians Amt and Hedemarkens Amt. The name/form was changed to Kristians Amt in 1877, in 1919 the name Kristians Amt was changed to Opland fylke, and the form Oppland was settled in 1950. The coat of arms were granted in 1989, and it shows two Pulsatilla vernalis, Oppland County has a total of 26 municipalities, Media related to Oppland at Wikimedia Commons Oppland travel guide from Wikivoyage
Oppland
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Oppland fylke
47.
Norway
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The Antarctic Peter I Island and the sub-Antarctic Bouvet Island are dependent territories and thus not considered part of the Kingdom. Norway also lays claim to a section of Antarctica known as Queen Maud Land, until 1814, the kingdom included the Faroe Islands, Greenland, and Iceland. It also included Isle of Man until 1266, Shetland and Orkney until 1468, Norway has a total area of 385,252 square kilometres and a population of 5,258,317. The country shares a long border with Sweden. Norway is bordered by Finland and Russia to the north-east, Norway has an extensive coastline, facing the North Atlantic Ocean and the Barents Sea. King Harald V of the Dano-German House of Glücksburg is the current King of Norway, erna Solberg became Prime Minister in 2013, replacing Jens Stoltenberg. A constitutional monarchy, Norway divides state power between the Parliament, the Cabinet and the Supreme Court, as determined by the 1814 Constitution, the kingdom is established as a merger of several petty kingdoms. By the traditional count from the year 872, the kingdom has existed continuously for 1,144 years, Norway has both administrative and political subdivisions on two levels, counties and municipalities. The Sámi people have an amount of self-determination and influence over traditional territories through the Sámi Parliament. Norway maintains close ties with the European Union and the United States, the country maintains a combination of market economy and a Nordic welfare model with universal health care and a comprehensive social security system. Norway has extensive reserves of petroleum, natural gas, minerals, lumber, seafood, the petroleum industry accounts for around a quarter of the countrys gross domestic product. On a per-capita basis, Norway is the worlds largest producer of oil, the country has the fourth-highest per capita income in the world on the World Bank and IMF lists. On the CIAs GDP per capita list which includes territories and some regions, from 2001 to 2006, and then again from 2009 to 2017, Norway had the highest Human Development Index ranking in the world. It also has the highest inequality-adjusted ranking, Norway ranks first on the World Happiness Report, the OECD Better Life Index, the Index of Public Integrity and the Democracy Index. Norway has two names, Noreg in Nynorsk and Norge in Bokmål. The name Norway comes from the Old English word Norðrveg mentioned in 880, meaning way or way leading to the north. In contrasting with suðrvegar southern way for Germany, and austrvegr eastern way for the Baltic, the Anglo-Saxon of Britain also referred to the kingdom of Norway in 880 as Norðmanna land. This was the area of Harald Fairhair, the first king of Norway, and because of him
Norway
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The
helmet found at Gjermundbu near
Haugsbygd,
Buskerud, is the only
Viking Age helmet that has been found.
Norway
–
Flag
Norway
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The
Gokstad ship at the
Viking Ship Museum in
Oslo, Norway
Norway
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The
Battle of the Sound between an allied Dano-Norwegian–
Dutch fleet and the Swedish navy, 8 November 1658 (29 October
O.S.)
48.
Himalayas
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The Himalayas, or Himalaya, form a mountain range in Asia separating the plains of the Indian subcontinent from the Tibetan Plateau. The Himalayan range has the Earths highest peaks, including the highest, the Himalayas include over a hundred mountains exceeding 7,200 metres in elevation. By contrast, the highest peak outside Asia – Aconcagua, in the Andes – is 6,961 metres tall. The Himalayas are spread across five countries, Bhutan, India, Nepal, China, the Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the major rivers, the Indus, the Ganges, and the Tsangpo-Brahmaputra, rise in the Himalayas. The Himalayas have profoundly shaped the cultures of South Asia, many Himalayan peaks are sacred in Hinduism and Buddhism. Lifted by the subduction of the Indian tectonic plate under the Eurasian Plate and its western anchor, Nanga Parbat, lies just south of the northernmost bend of Indus river. Its eastern anchor, Namcha Barwa, is just west of the bend of the Tsangpo river. The range varies in width from 400 kilometres in the west to 150 kilometres in the east, the name of the range derives from the Sanskrit Himā-laya, from himá and ā-laya. They are now known as the Himalaya Mountains, usually shortened to the Himalayas, formerly, they were described in the singular as the Himalaya. This was also previously transcribed Himmaleh, as in Emily Dickinsons poetry and Henry David Thoreaus essays. The mountains are known as the Himālaya in Nepali and Hindi, the Himalaya or The Land of Snow in Tibetan, the Hamaleh Mountain Range in Urdu, the flora and fauna of the Himalayas vary with climate, rainfall, altitude, and soils. The climate ranges from tropical at the base of the mountains to permanent ice, the amount of yearly rainfall increases from west to east along the southern front of the range. This diversity of altitude, rainfall and soil conditions combined with the high snow line supports a variety of distinct plant. The extremes of high altitude combined with extreme cold favor extremophile organisms, the unique floral and faunal wealth of the Himalayas is undergoing structural and compositional changes due to climate change. The increase in temperature is shifting various species to higher elevations, the oak forest is being invaded by pine forests in the Garhwal Himalayan region. There are reports of early flowering and fruiting in some species, especially rhododendron, apple. The highest known tree species in the Himalayas is Juniperus tibetica located at 4,900 metres in Southeastern Tibet, the Himalayan range is one of the youngest mountain ranges on the planet and consists mostly of uplifted sedimentary and metamorphic rock
Himalayas
–
The north face of
Mount Everest seen from the path to the base camp in
Tibet Autonomous Region,
China
Himalayas
Himalayas
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Panoramic view of Langtang Range in
Nepal
Himalayas
–
Indus River
49.
Tibetan Plateau
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It stretches approximately 1,000 kilometres north to south and 2,500 kilometres east to west. Sometimes termed the Third Pole, the Tibetan Plateau contains the headwaters of the basins of most of the streams in surrounding regions. Its tens of thousands of glaciers and other geographical and ecological features serve as a water tower storing water, the impact of global warming on the Tibetan Plateau is of intense scientific interest. The Tibetan Plateau is surrounded by mountain ranges. In the west the curve of the rugged Karakoram range of northern Kashmir embraces the plateau, the Indus River originates in the western Tibetan Plateau in the vicinity of Lake Mansarovar. The Tibetan Plateau is bounded in the north by an escarpment where the altitude drops from around 5,000 metres to 1,500 metres over a horizontal distance of less than 150 kilometres. Along the escarpment is a range of mountains, in the west the Kunlun Mountains separate the plateau from the Tarim Basin. About halfway across the Tarim the bounding range becomes the Altyn-Tagh, in the V formed by this split is the western part of the Qaidam Basin. The Altyn-Tagh ends near the Dangjin pass on the Dunhuang-Golmud road, to the west are short ranges called the Danghe, Yema, Shule, and Tulai Nanshans. The easternmost range is the Qilian Mountains, the line of mountains continues east of the plateau as the Qin Mountains which separate the Ordos Region from Sichuan. North of the runs the Gansu or Hexi Corridor which was the main silk-road route from China proper to the West. The plateau is an arid steppe interspersed with mountain ranges. Annual precipitation ranges from 100 to 300 millimetres and falls mainly as hail, the southern and eastern edges of the steppe have grasslands which can sustainably support populations of nomadic herdsmen, although frost occurs for six months of the year. Permafrost occurs over parts of the plateau. Proceeding to the north and northwest, the plateau becomes progressively higher, colder and drier, here the average altitude exceeds 5,000 metres and winter temperatures can drop to −40 °C. The geological history of the Tibetan Plateau is closely related to that of the Himalayan mountain range, the Himalayas are among the youngest mountain ranges on the planet and consist mostly of uplifted sedimentary and metamorphic rock. Their formation is a result of a collision or orogeny along the convergent boundary between the Indo-Australian Plate and the Eurasian Plate. The collision began in the Upper Cretaceous period about 70 million years ago, since these sediments were light, they crumpled into mountain ranges rather than sinking to the floor
Tibetan Plateau
–
Buddhist stupa and houses outside the town of
Aba, on the Tibetan Plateau.
Tibetan Plateau
–
The Qinghai-Tibetan Plateau lies between the
Himalayan range to the south and the
Kunlun Range to the north.
Tibetan Plateau
–
NASA satellite image of the south-eastern area of Tibetan Plateau.
Brahmaputra River is in the lower right.
Tibetan Plateau
–
The Tibetan Plateau lies between the
Himalayan range to the south and the
Taklamakan Desert to the north.
50.
Atacama Desert
–
The Atacama Desert is a plateau in South America, covering a 1, 000-kilometre strip of land on the Pacific coast, west of the Andes mountains. It is the driest non-polar desert in the world, according to estimates, the Atacama Desert proper occupies 105,000 square kilometres, or 128,000 square kilometres if the barren lower slopes of the Andes are included. Most of the desert is composed of terrain, salt lakes, sand. The National Geographic Society considers the area of southern Peru to be part of the Atacama Desert. Peru borders it on the north and the Chilean Matorral ecoregion borders it on the south, to the east lies the less arid Central Andean dry puna ecoregion. The drier portion of this ecoregion is located south of the Loa River between the parallel Sierra Vicuña Mackenna and Cordillera Domeyko, to the north of the Loa lies the Pampa del Tamarugal. The Coastal Cliff of northern Chile west of the Chilean Coast Range is the topographic feature of the coast. The geomorphology of the Atacama Desert has been characterized as a low-relief bench similar to a giant uplifted terrace by Armijo and co-workers. The intermediate depression forms a series of basins in much of Atacama Desert south of latitude 19°30’ S. North of this latitude the intermediate depression drains into the Pacific Ocean. Although the almost total lack of precipitation is the most prominent characteristic of the Atacama Desert, in 2012, the altiplano winter brought floods to San Pedro de Atacama. On 25 March 2015, heavy rainfall affected the part of the Atacama desert. Resulting floods triggered mudflows that affected the cities of Copiapo, Tierra Amarilla, Chile, Chanaral, the Atacama Desert is commonly known as the driest non-polar place in the world, especially the surroundings of the abandoned Yungay town. The average rainfall is about 15 mm per year, although some locations, such as Arica and Iquique, moreover, some weather stations in the Atacama have never received rain. Periods of up to four years have been registered with no rainfall in the sector, delimited by the cities of Antofagasta, Calama and Copiapó. Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971, the Atacama Desert may be the oldest desert on earth, and has experienced extreme hyperaridity for at least 3 million years, making it the oldest continuously arid region on earth. The long history of aridity raises the possibility that supergene mineralisation, under the conditions, can form in arid environments. This desert is so arid, many mountains higher than 6,000 m are free of glaciers. Only the highest peaks have some permanent snow coverage, the southern part of the desert, between 25 and 27°S, may have been glacier-free throughout the Quaternary, though permafrost extends down to an altitude of 4,400 m and is continuous above 5,600 m
Atacama Desert
–
A flat area of the Atacama Desert between Antofagasta and
Taltal
Atacama Desert
–
Atacama by
NASA World Wind
Atacama Desert
–
Snow in
Paranal Observatory at 2,600
masl.
Atacama Desert
–
Rare rainfall events cause the
flowering desert phenomenon in the southern Atacama Desert
