The horizon or skyline is the apparent line that separates earth from sky, the line that divides all visible directions into two categories: those that intersect the Earth's surface, those that do not. The true horizon is a theoretical line, which can only be observed when it lies on the sea surface. At many locations, this line is obscured by land, buildings, etc. and the resulting intersection of earth and sky is called the visible horizon. When looking at a sea from a shore, the part of the sea closest to the horizon is called the offing; the true horizon is horizontal. It surrounds the observer and it is assumed to be a circle, drawn on the surface of a spherical model of the Earth, its center is below sea level. Its distance from the observer varies from day to day due to atmospheric refraction, affected by weather conditions; the higher the observer's eyes are from sea level, the farther away is the horizon from the observer. For instance, in standard atmospheric conditions, for an observer with eye level above sea level by 1.70 metres, the horizon is at a distance of about 5 kilometres.
When observed from high standpoints, such as a space station, the horizon is much farther away and it encompasses a much larger area of Earth's surface. In this case, it becomes evident that the horizon more resembles an ellipse than a perfect circle when the observer is above the equator, that the Earth's surface can be better modeled as an ellipsoid than as a sphere; the word horizon derives from the Greek "ὁρίζων κύκλος" horizōn kyklos, "separating circle", where "ὁρίζων" is from the verb ὁρίζω horizō, "to divide", "to separate", which in turn derives from "ὅρος", "boundary, landmark". The distance to the visible horizon has long been vital to survival and successful navigation at sea, because it determined an observer's maximum range of vision and thus of communication, with all the obvious consequences for safety and the transmission of information that this range implied; this importance lessened with the development of the radio and the telegraph, but today, when flying an aircraft under visual flight rules, a technique called attitude flying is used to control the aircraft, where the pilot uses the visual relationship between the aircraft's nose and the horizon to control the aircraft.
A pilot can retain his or her spatial orientation by referring to the horizon. In many contexts perspective drawing, the curvature of the Earth is disregarded and the horizon is considered the theoretical line to which points on any horizontal plane converge as their distance from the observer increases. For observers near sea level the difference between this geometrical horizon and the true horizon is imperceptible to the naked eye. In astronomy the horizon is the horizontal plane through the eyes of the observer, it is the fundamental plane of the horizontal coordinate system, the locus of points that have an altitude of zero degrees. While similar in ways to the geometrical horizon, in this context a horizon may be considered to be a plane in space, rather than a line on a picture plane. One sees further along the Earth's curved surface than a simple geometric calculation allows for because of refraction error. If the ground, or water, surface is colder than the air above it, a cold, dense layer of air forms close to the surface, causing light to be refracted downward as it travels, therefore, to some extent, to go around the curvature of the Earth.
The reverse happens if the ground is hotter than the air above it, as happens in deserts, producing mirages. As an approximate compensation for refraction, surveyors measuring distances longer than 100 meters subtract 14% from the calculated curvature error and ensure lines of sight are at least 1.5 meters from the ground, to reduce random errors created by refraction. However, ignoring the effect of atmospheric refraction, distance to the true horizon from an observer close to the Earth's surface is about d ≈ 3.57 h, where d is in kilometres and h is height above sea level in metres. The constant 3.57 has units of km/m½. When d is measured in miles and h in feet, the distance is d ≈ 1.5 h ≈ 1.22 h. where the constant 1.22 has units of mi/ft½. In this equation Earth's surface is assumed to be spherical, with radius equal to about 6,371 kilometres. Assuming no atmospheric refraction and a spherical Earth with radius R=6,371 kilometres: For an observer standing on the ground with h = 1.70 metres, the horizon is at a distance of 4.7 kilometres.
For an observer standing on the ground with h = 2 metres, the horizon is at a distance of 5 kilometres. For an observer standing on a hill or tower 100 feet above sea level, the horizon is at a distance of 12.2 miles. For an observer standing on a hill or tower 100 metres above sea level, the horizon is at a distance of 36 kilometres. For an observer standing on the roof of the Burj Khalifa, 828 metres from ground, about 834 metres above sea level, the horizon is at a distance of 103 kilometres. For an observe
Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Fog can be considered a type of low-lying cloud resembling stratus, is influenced by nearby bodies of water and wind conditions. In turn, fog has affected many human activities, such as shipping and warfare; the term "fog" is distinguished from the more generic term "cloud" in that fog is low-lying, the moisture in the fog is generated locally. By definition, fog reduces visibility to less than 1 kilometre, whereas mist causes lesser impairment of visibility. For aviation purposes in the UK, a visibility of less than 5 kilometres but greater than 999 metres is considered to be mist if the relative humidity is 95% or greater. Fog forms when the difference between air temperature and dew point is less than 2.5 °C. Fog begins to form when water vapor condenses into tiny liquid water droplets that are suspended in the air. Six examples of ways that water vapor is added to the air are by wind convergence into areas of upward motion.
Water vapor begins to condense on condensation nuclei such as dust and salt in order to form clouds. Fog, like its elevated cousin stratus, is a stable cloud deck which tends to form when a cool, stable air mass is trapped underneath a warm air mass. Fog occurs at a relative humidity near 100%; this occurs from either added moisture in the air, or falling ambient air temperature. However, fog can form at lower humidities, can sometimes fail to form with relative humidity at 100%. At 100% relative humidity, the air cannot hold additional moisture, the air will become supersaturated if additional moisture is added. Fog produces precipitation in the form of drizzle or light snow. Drizzle occurs when the humidity of fog attains 100% and the minute cloud droplets begin to coalesce into larger droplets; this can occur when the fog layer is lifted and cooled sufficiently, or when it is forcibly compressed from above by descending air. Drizzle becomes freezing drizzle; the thickness of a fog layer is determined by the altitude of the inversion boundary, which in coastal or oceanic locales is the top of the marine layer, above which the air mass is warmer and drier.
The inversion boundary varies its altitude in response to the weight of the air above it, measured in terms of atmospheric pressure. The marine layer, any fogbank it may contain, will be "squashed" when the pressure is high, conversely, may expand upwards when the pressure above it is lowering. Fog can form in a number of ways, depending on how the cooling that caused the condensation occurred. Radiation fog is formed by the cooling of land after sunset by infrared thermal radiation in calm conditions with a clear sky; the cooling ground cools adjacent air by conduction, causing the air temperature to fall and reach the dew point, forming fog. In perfect calm, the fog layer can be less than a meter thick, but turbulence can promote a thicker layer. Radiation fog occurs at night, does not last long after sunrise, but it can persist all day in the winter months in areas bounded by high ground. Radiation fog is most common in early winter. Examples of this phenomenon include the Tule fog. Ground fog is fog that obscures less than 60% of the sky and does not extend to the base of any overhead clouds.
However, the term is a synonym for shallow radiation fog. Advection fog occurs when moist air is cooled, it is common. It is most common at sea when moist air encounters cooler waters, including areas of cold water upwelling, such as along the California coast. A strong enough temperature difference over water or bare ground can cause advection fog. Although strong winds mix the air and can disperse, fragment, or prevent many kinds of fog, markedly warmer and humid air blowing over a snowpack can continue to generate advection fog at elevated velocities up to 80 km/h or more – this fog will be in a turbulent moving, comparatively shallow layer, observed as a few centimeters/inches in depth over flat farm fields, flat urban terrain and the like, and/or form more complex forms where the terrain is different such as rotating areas in the lee of hills or large buildings and so on. Fog formed by advection along the California coastline is propelled onto land by one of several processes. A cold front can push the marine layer coast-ward, an occurrence most typical in the spring or late fall.
During the summer months, a low pressure trough produced by intense heating inland creates a strong pressure gradient, drawing in the dense marine layer. During the summer, strong high pressure aloft over the desert southwest in connection with the summer monsoon, produces a south to southeasterly flow which can drive the offshore marine layer up the coastline. However, if the monsoonal flow is sufficiently turbulent, it might instead break up the marine layer a
Lake-effect snow is produced during cooler atmospheric conditions when a cold air mass moves across long expanses of warmer lake water, warming the lower layer of air which picks up water vapor from the lake, rises up through the colder air above, freezes and is deposited on the leeward shores. The same effect occurs over bodies of salt water, when it is termed ocean-effect or bay-effect snow; the effect is enhanced when the moving air mass is uplifted by the orographic influence of higher elevations on the downwind shores. This uplifting can produce narrow but intense bands of precipitation, which deposit at a rate of many inches of snow each hour resulting in a large amount of total snowfall; the areas affected by lake-effect snow are called snowbelts. These include areas east of the Great Lakes, the west coasts of northern Japan, the Kamchatka Peninsula in Russia, areas near the Great Salt Lake, Black Sea, Caspian Sea, Baltic Sea, the Adriatic Sea. Lake-effect blizzards are the blizzard-like conditions resulting from lake-effect snow.
Under certain conditions, strong winds can accompany lake-effect snows creating blizzard-like conditions. If the air temperature is low enough to keep the precipitation frozen, it falls as lake-effect snow. If not it falls as lake-effect rain. For lake-effect rain or snow to form, the air moving across the lake must be cooler than the surface air; 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 water surface can produce thundersnow, snow showers accompanied by lightning and thunder. There are some key elements that are required to form lake-effect precipitation and which determine its characteristics: instability, wind shear, upstream moisture, upwind lakes, synoptic -scale forcing, orography/topography, snow or ice cover. A temperature difference of 13 °C between the lake temperature and the height in the atmosphere provides for absolute instability and allows vigorous heat and moisture transportation vertically.
Atmospheric lapse rate and convective depth are directly affected by both the mesoscale lake environment and the synoptic environment. 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. 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; as the air mass reaches the other side of the lake, the engine of rising and cooling water vapor pans itself out in the form of condensation and falls as snow within 40 kilometers of the lake but sometimes up to about 100 miles. Directional shear is one of the most important factors governing the development of squalls. If directional shear between the surface and the height in the atmosphere at which the barometric pressure measures 700 mb is greater than 60 degrees, nothing more than flurries can be expected.
If the directional shear between the body of water and the vertical 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, well organized bands can be expected. Speed shear is less critical, but should be uniform; the wind speed difference between the surface and vertical height at which the pressure reads 700 mb should be no greater than 40 knots so as to prevent the upper portions of the band from shearing off. However, assuming the surface to 700 mb winds are uniform, a faster overall velocity will work to transport moisture quicker from the water, the band will travel much farther inland. A lower upstream relative humidity will make it more difficult and time consuming for lake effect condensation and precipitation to form; the opposite is true if the upstream moisture has a high relative humidity, allowing lake effect condensation and precipitation to form more and in a greater quantity.
Any large body of water upwind will impact lake-effect precipitation to the lee of a downwind lake by adding moisture or pre-existing lake-effect bands, which can re-intensify over the downwind lake. 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 precipitation will increase with elevation to the lee of the lake as topographic forcing squeezes out precipitation and dries out the squall much faster
Air New Zealand Flight 901
Air New Zealand Flight 901 was a scheduled Air New Zealand Antarctic sightseeing flight that operated between 1977 and 1979. The flight would leave Auckland Airport in the morning and spend a few hours flying over the Antarctic continent, before returning to Auckland in the evening via Christchurch. On 28 November 1979, the fourteenth flight of TE-901, a McDonnell Douglas DC-10-30, registration ZK-NZP, flew into Mount Erebus on Ross Island, killing all 237 passengers and 20 crew on board; the accident became known as the Mount Erebus disaster. The initial investigation concluded the accident was caused by pilot error, but public outcry led to the establishment of a Royal Commission of Inquiry into the crash; the commission, presided over by Justice Peter Mahon QC, concluded that the accident was caused by a correction made to the coordinates of the flight path the night before the disaster, coupled with a failure to inform the flight crew of the change, with the result that the aircraft, instead of being directed by computer down McMurdo Sound, was instead re-routed to a path toward Mount Erebus.
Justice Mahon's report accused Air New Zealand of presenting "an orchestrated litany of lies" and this led to changes in senior management at the airline. The accident is New Zealand's deadliest peacetime disaster, as well as the deadliest accident in the history of Air New Zealand; the flight was designed and marketed as a unique sightseeing experience, carrying an experienced Antarctic guide who pointed out scenic features and landmarks using the aircraft public-address system, while passengers enjoyed a low-flying sweep of McMurdo Sound. The flights returned to New Zealand the same day. Flight 901 would leave Auckland International Airport at 8:00 am for Antarctica, arrive back at Christchurch International Airport at 7:00 pm after flying a total of 5,360 miles; the aircraft would make a 45-minute stop at Christchurch for refuelling and crew change, before flying the remaining 464 miles to Auckland, arriving at 9:00 pm. Tickets for the November 1979 flights cost NZ$359 per person. Dignitaries including Sir Edmund Hillary had acted as guides on previous flights.
Hillary was scheduled to act as the guide for the fatal flight of 28 November 1979, but had to cancel owing to other commitments. His long-time friend and climbing companion, Peter Mulgrew, stood in as guide; the flights operated at about 85% of capacity. The aircraft used on the Antarctic flights were Air New Zealand's eight McDonnell Douglas DC-10-30 trijets; the aircraft on 28 November was registered ZK-NZP. The 182nd DC-10 to be built, the fourth DC-10 to be introduced by Air New Zealand, ZK-NZP was handed over to the airline on 12 December 1974 at McDonnell Douglas's Long Beach plant, it was the first Air New Zealand DC-10 to be fitted with General Electric CF6-50C engines as built, had logged more than 20,700 flight hours prior to the crash. Captain Jim Collins and co-pilot Greg Cassin had never flown to Antarctica before, but they were experienced pilots and were considered qualified for the flight. On 9 November 1979, 19 days before departure, the two pilots attended a briefing in which they were given a copy of the previous flight's flight plan.
The flight plan, approved in 1977 by the New Zealand Department of Transport Civil Aviation Division was along a track directly from Cape Hallett to the McMurdo non-directional beacon, coincidentally, entailed flying directly over the 12,448-foot peak of Mount Erebus. However, because of a typing error in the coordinates when the route was computerised, the printout from Air New Zealand's ground computer system presented at the 9 November briefing corresponded to a southerly flight path down the middle of the wide McMurdo Sound 27 miles to the west of Mount Erebus; the majority of the previous 13 flights had entered this flight plan's coordinates into their aircraft navigational systems and flown the McMurdo Sound route, unaware that the route flown did not correspond with the approved route. Captain Leslie Simpson, the pilot of a flight on 14 November and present at the 9 November briefing, compared the coordinates of the McMurdo TACAN navigation beacon, the McMurdo waypoint that his flight crew had entered into the INS, was surprised to find a large distance between the two.
After his flight, Captain Simpson advised Air New Zealand's Navigation section of the difference in positions. For reasons that were disputed, this triggered Air New Zealand's Navigation section to resolve to update the McMurdo waypoint coordinates stored in the ground computer to correspond with the coordinates of the McMurdo TACAN beacon, despite this not corresponding with the approved route; the Navigation section changed the McMurdo waypoint coordinate stored in the ground computer system at 1:40 am on the morning of the flight. Crucially, the flight crew of Flight 901 was not notified of the change; the flight plan printout given to the crew on the morning of the flight, subsequently entered by them into the aircraft's INS, differed from the flight plan presented at the 9 November briefing and from Captain Collins' map mark-ups which he had prepared the night before the fatal flight. The key difference was that the flight plan presented at the briefing corresponded to a track down McMurdo Sound, giving Mount Erebus a wide berth to the ea
Sir Edmund Percival Hillary was a New Zealand mountaineer and philanthropist. On 29 May 1953, Hillary and Nepalese Sherpa mountaineer Tenzing Norgay became the first climbers confirmed to have reached the summit of Mount Everest, they were part of the ninth British expedition to Everest, led by John Hunt. From 1985 to 1988 he served as New Zealand's High Commissioner to India and Bangladesh and concurrently as Ambassador to Nepal. Hillary became interested in mountaineering while in secondary school, he made his first major climb in 1939. He served in the Royal New Zealand Air Force as a navigator during World War II. Prior to the Everest expedition, Hillary had been part of the British reconnaissance expedition to the mountain in 1951 as well as an unsuccessful attempt to climb Cho Oyu in 1952; as part of the Commonwealth Trans-Antarctic Expedition he reached the South Pole overland in 1958. He subsequently reached the North Pole, making him the first person to reach both poles and summit Everest.
Following his ascent of Everest, Hillary devoted himself to assisting the Sherpa people of Nepal through the Himalayan Trust, which he established. His efforts are credited with the construction of many hospitals in Nepal. Hillary had numerous honours conferred upon him, including the Order of the Garter in 1995. Upon his death in 2008, he was given a state funeral in New Zealand. Hillary was born to Percival Augustus and Gertrude Hillary in Auckland, New Zealand, on 20 July 1919, his father Percy had served at Gallipoli with the 15th Regiment, was discharged "medically unfit" from the Army in 1916. His grandparents had emigrated from Yorkshire to northern Wairoa in the mid-19th century, his family moved to Tuakau, south of Auckland, in 1920, after Percy was allocated eight acres of land there as a returned soldier. Percy had been a journalist prewar, soon became founding editor of the weekly Tuakau District News as well as an apiarist. Ed had a brother Rex. Hillary was educated at Tuakau Primary School and Auckland Grammar School.
He finished primary school aged 11 or two years early, at "Grammar" achieved average marks. His mother wanted him to go to a "good school" and he commuted by train, cycling to Tuakau station before 7 am and returning after 6 pm for 3½ years until the family moved to Remuera, Auckland in 1935, his last of four years at "Grammar", he was smaller than his peers and shy, did not enjoy "Grammar", where commuting barred him from after-school activities. He gained confidence after taking up boxing, he became interested in climbing when he was 16 following a 1935 school trip to Mount Ruapehu, after which he showed more interest in tramping than in studying and said he "wanted to see the world". He attended Auckland University College, joined the Tramping Club there, but in 1938 "after two notably unsuccessful years studying mathematics and science" he gave up on formal education. He became an apiarist with his father and brother Rex. So he kept bees in summer, concentrated on climbing in winter, his father edited the journal "The N.
Z. Honeybee" and his mother Gertrude was famous for selling queen bees. In 1938 he went to hear Herbert Sutcliffe, the proponent of a life philosophy called "Radiant Living", with his family; the family all became foundation members, his mother became its secretary in 1939. He went to Gisborne as Sutcliff’s assistant, in 1941 sat examinations to become a teacher of Radiant Living, getting a 100% pass mark, his test lecture was on "Inferiority – cause and cure". He said of his five year association with the movement that "I learned to speak confidently from the platform. Tenets included healthy pacificism, he joined the Radiant Living Tramping Club, further developed his love of the outdoors in the Waitakere Ranges. In 1939 he completed his first major climb, reaching the summit of Mount Ollivier, near Aoraki / Mount Cook in the Southern Alps. Climbing brought new friends. At the outbreak of World War II, Hillary applied to join the Royal New Zealand Air Force but withdrew the application writing that he was "harassed by my religious conscience".
In 1943, with the Japanese threat in the Pacific and the arrival of conscription, he joined the RNZAF as a navigator in No. 6 Squadron RNZAF and No. 5 Squadron RNZAF on Catalina flying boats. In 1945, he was sent to the Solomon Islands, where he was badly burnt in an accident. In January 1948, Hillary and others ascended the south ridge of Aoraki / Mount Cook, New Zealand's highest peak. In 1951 he was part of a British reconnaissance expedition to Everest led by Eric Shipton, before joining the successful British attempt of 1953. In 1952, Hillary and George Lowe were part of the British team led by Shipton, that attempted Cho Oyu. After that attempt failed due to the lack of route from the Nepal side and Lowe crossed the Nup La pass into Tibet and reached the old Camp II, on the northern side, where all the previous expeditions had camped. In 1949, the long-standing climbing route to the summit of Everest was closed by Chinese-controlled Tibet. For the next several years, Nepal allowed only one or two expeditions p
Proprioception, is the sense of self-movement and body position. It is sometimes described as the "sixth sense". Proprioception is mediated by mechanically-sensitive proprioceptor neurons distributed throughout an animal's body. Most vertebrates possess three basic types of proprioceptors: muscle spindles, which are embedded in skeletal muscle fibers, Golgi tendon organs, which lie at the interface of muscles and tendons, joint receptors, which are low-threshold mechanoreceptors embedded in joint capsules. Many invertebrates, such as insects possess three basic proprioceptor types with analogous functional properties: chordotonal neurons, campaniform sensilla, hair plates; the central nervous system integrates information from proprioception and other sensory systems, such as vision and the vestibular system, to create an overall representation of body position and acceleration. The sense of proprioception is ubiquitous across mobile animals, is essential for the motor coordination of the body.
More proprioception has been described in flowering land plants. Proprioception is from Latin proprius, meaning "one's own", "individual", capio, capere, to take or grasp, thus to grasp one's own position in space, including the position of the limbs in relation to each other and the body as a whole. The word kinesthesia or kinæsthesia refers to movement sense, but has been used inconsistently to refer either to proprioception alone or to the brain's integration of proprioceptive and vestibular inputs. Kinesthesia is a modern medical term composed of elements from Greek; the position-movement sensation was described in 1557 by Julius Caesar Scaliger as a "sense of locomotion". Much in 1826, Charles Bell expounded the idea of a "muscle sense", credited as one of the first descriptions of physiologic feedback mechanisms. Bell's idea was that commands are carried from the brain to the muscles, that reports on the muscle's condition would be sent in the reverse direction. In 1847 the London neurologist Robert Todd highlighted important differences in the anterolateral and posterior columns of the spinal cord, suggested that the latter were involved in the coordination of movement and balance.
At around the same time, Moritz Heinrich Romberg, a Berlin neurologist, was describing unsteadiness made worse by eye closure or darkness, now known as the eponymous Romberg's sign, once synonymous with tabes dorsalis, that became recognised as common to all proprioceptive disorders of the legs. In 1880, Henry Charlton Bastian suggested "kinaesthesia" instead of "muscle sense" on the basis that some of the afferent information comes from other structures, including tendons and skin. In 1889, Alfred Goldscheider suggested a classification of kinaesthesia into three types: muscle and articular sensitivity. In 1906, Charles Scott Sherrington published a landmark work that introduced the terms "proprioception", "interoception", "exteroception"; the "exteroceptors" are the organs that provide information originating outside the body, such as the eyes, ears and skin. The interoceptors provide information about the internal organs, the "proprioceptors" provide information about movement derived from muscular and articular sources.
Using Sherrington's system and anatomists search for specialised nerve endings that transmit mechanical data on joint capsule and muscle tension, which play a large role in proprioception. Primary endings of muscle spindles "respond to the size of a muscle length change and its speed" and "contribute both to the sense of limb position and movement". Secondary endings of muscle spindles detect changes in muscle length, thus supply information regarding only the sense of position. Muscle spindles are stretch receptors, it has been accepted that cutaneous receptors contribute directly to proprioception by providing "accurate perceptual information about joint position and movement", this knowledge is combined with information from the muscle spindles. A major component of proprioception is joint position sense, determined by measuring the accuracy of joint–angle replication. Clinical aspects of joint position sense are measured in joint position matching tests that measure a subject's ability to detect an externally imposed passive movement, or the ability to reposition a joint to a predetermined position.
These involve an individual's ability to perceive the position of a joint without the aid of vision. It is assumed that the ability of one of these aspects will be related to another; this suggests that while these components may well be related in a cognitive manner, they may in fact be physiologically separate. More recent work into the mechanism of ankle sprains suggests that the role of reflexes may be more limited due to their long latencies, as ankle sprain events occur in 100 ms or less. In accordance, a model has been proposed to include a'feedforward' component of proprioception, whereby the subject will have central information about the body's position before attaining it. Kinesthesia is a key component in muscle memory and hand-eye coordination, training can improve this sense; the ability to swing a golf club or to catch a ball requires a finely tuned sense of the position o
A landscape is the visible features of an area of land, its landforms, how they integrate with natural or man-made features. A landscape includes the physical elements of geophysically defined landforms such as mountains, water bodies such as rivers, lakes and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of land use and structures, transitory elements such as lighting and weather conditions. Combining both their physical origins and the cultural overlay of human presence created over millennia, landscapes reflect a living synthesis of people and place, vital to local and national identity; the character of a landscape helps define the self-image of the people who inhabit it and a sense of place that differentiates one region from other regions. It is the dynamic backdrop to people's lives. Landscape can be as varied as a landscape park or wilderness; the Earth has a vast range of landscapes, including the icy landscapes of polar regions, mountainous landscapes, vast arid desert landscapes and coastal landscapes, densely forested or wooded landscapes including past boreal forests and tropical rainforests, agricultural landscapes of temperate and tropical regions.
The activity of modifying the visible features of an area of land is referred to as landscaping. There are several definitions of. In common usage however, a landscape refers either to all the visible features of an area of land considered in terms of aesthetic appeal, or to a pictorial representation of an area of countryside within the genre of landscape painting; when people deliberately improve the aesthetic appearance of a piece of land—by changing contours and vegetation, etc.—it is said to have been landscaped, though the result may not constitute a landscape according to some definitions. The word landscape arrived in England—and therefore into the English language—after the fifth century, following the arrival of the Anglo-Saxons; the term landscape emerged around the turn of the sixteenth century to denote a painting whose primary subject matter was natural scenery. Land may be taken in its sense of something; the suffix ‑scape is equivalent to the more common English suffix ‑ship. The roots of ‑ ship are etymologically akin to Old English scyppan, meaning to shape.
The suffix ‑schaft is related to the verb schaffen, so that ‑ship and shape are etymologically linked. The modern form of the word, with its connotations of scenery, appeared in the late sixteenth century when the term landschap was introduced by Dutch painters who used it to refer to paintings of inland natural or rural scenery; the word landscape, first recorded in 1598, was borrowed from a Dutch painters' term. The popular conception of the landscape, reflected in dictionaries conveys both a particular and a general meaning, the particular referring to an area of the Earth's surface and the general being that which can be seen by an observer. An example of this second usage can be found as early as 1662 in the Book of Common Prayer: Could we but climb where Moses stood, And view the landscape over.. There are several words that are associated with the word landscape: Scenery: The natural features of a landscape considered in terms of their appearance, esp. when picturesque: spectacular views of mountain scenery.
Setting: In works of narrative, it includes the historical moment in time and geographic location in which a story takes place, helps initiate the main backdrop and mood for a story. Picturesque: The word means "in the manner of a picture. Gilpin’s Essay on Prints defined picturesque as "a term expressive of that peculiar kind of beauty, agreeable in a picture". A view: "A sight or prospect of some landscape or extended scene. Wilderness: An uncultivated and inhospitable region. See Natural landscape. Cityscape: The urban equivalent of a landscape. In the visual arts a cityscape is an artistic representation, such as a painting, print or photograph, of the physical aspects of a city or urban area. Seascape: A photograph, painting, or other work of art which depicts the sea, in other words an example of marine art. Geomorphology is the scientific study of the origin and evolution of topographic and bathymetric features created by physical or chemical processes operating at or near Earth's surface.
Geomorphologists seek to understand why landscapes look the way they do, to understand landform history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphology is practiced within physical geography, geodesy, engineering geology and geotechnical engineering; this broad base of interests contributes to many research interests within the field. The surface of Earth is modified by a combination of surface processes that sculpt landscapes, geologic processes that cause tectonic uplift and subsidence, shape the coastal geography. Surface processes comprise the action of water, ice and living things on the surface of the Earth, along with chemical reactions that form soils and alter material properties