A mountain is a large landform that rises above the surrounding land in a limited area in the form of a peak. A mountain is steeper than a hill. Mountains are formed through tectonic forces or volcanism; these forces can locally raise the surface of the earth. Mountains erode through the action of rivers, weather conditions, glaciers. A few mountains are isolated summits. High elevations on mountains produce colder climates than at sea level; these colder climates affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains tend to be used less for agriculture and more for resource extraction and recreation, such as mountain climbing; the highest mountain on Earth is Mount Everest in the Himalayas of Asia, whose summit is 8,850 m above mean sea level. The highest known mountain on any planet in the Solar System is Olympus Mons on Mars at 21,171 m. There is no universally accepted definition of a mountain.
Elevation, relief, steepness and continuity have been used as criteria for defining a mountain. In the Oxford English Dictionary a mountain is defined as "a natural elevation of the earth surface rising more or less abruptly from the surrounding level and attaining an altitude which to the adjacent elevation, is impressive or notable."Whether a landform is called a mountain may depend on local usage. Mount Scott outside Lawton, Oklahoma, USA, is only 251 m from its base to its highest point. Whittow's Dictionary of Physical Geography states "Some authorities regard eminences above 600 metres as mountains, those below being referred to as hills." In the United Kingdom and the Republic of Ireland, a mountain is defined as any summit at least 2,000 feet high, whilst the official UK government's definition of a mountain, for the purposes of access, is a summit of 600 metres or higher. In addition, some definitions include a topographical prominence requirement 100 or 500 feet. At one time the U.
S. Board on Geographic Names defined a mountain as being 1,000 feet or taller, but has abandoned the definition since the 1970s. Any similar landform lower. However, the United States Geological Survey concludes that these terms do not have technical definitions in the US; the UN Environmental Programme's definition of "mountainous environment" includes any of the following: Elevation of at least 2,500 m. Using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, 14% of Africa; as a whole, 24% of the Earth's land mass is mountainous. There are three main types of mountains: volcanic and block. All three types are formed from plate tectonics: when portions of the Earth's crust move and dive. Compressional forces, isostatic uplift and intrusion of igneous matter forces surface rock upward, creating a landform higher than the surrounding features; the height of the feature makes it either a hill or, if steeper, a mountain. Major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity.
Volcanoes are formed when a plate is pushed at a mid-ocean ridge or hotspot. At a depth of around 100 km, melting occurs in rock above the slab, forms magma that reaches the surface; when the magma reaches the surface, it builds a volcanic mountain, such as a shield volcano or a stratovolcano. Examples of volcanoes include Mount Pinatubo in the Philippines; the magma does not have to reach the surface in order to create a mountain: magma that solidifies below ground can still form dome mountains, such as Navajo Mountain in the US. Fold mountains occur when two plates collide: shortening occurs along thrust faults and the crust is overthickened. Since the less dense continental crust "floats" on the denser mantle rocks beneath, the weight of any crustal material forced upward to form hills, plateaus or mountains must be balanced by the buoyancy force of a much greater volume forced downward into the mantle, thus the continental crust is much thicker under mountains, compared to lower lying areas.
Rock can fold either asymmetrically. The upfolds are anticlines and the downfolds are synclines: in asymmetric folding there may be recumbent and overturned folds; the Balkan Mountains and the Jura Mountains are examples of fold mountains. Block mountains are caused by faults in the crust: a plane; when rocks on one side of a fault rise relative to the other, it can form a mountain. The uplifted blocks are block horsts; the intervening dropped blocks are termed graben: these can be small or form extensive rift valley systems. This form of landscape can be seen in East Africa, the Vosges, the Basin and Range Province of Western North America and the Rhine valley; these areas occur when the regional stress is extensional and the crust is thinned. During and following uplift, mountains are subjected to the agents of erosion which wear the uplifted area down. Erosion causes the surface of mountains to be younger than the rocks that form the mountains themselves. Glacial processes produce characteristic landforms, such as pyramidal peaks, knife-edge arêtes, bowl-shaped cirques that can contai
A mountain range or hill range is a series of mountains or hills ranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form and alignment that have arisen from the same cause an orogeny. Mountain ranges are formed by a variety of geological processes, but most of the significant ones on Earth are the result of plate tectonics. Mountain ranges are found on many planetary mass objects in the Solar System and are a feature of most terrestrial planets. Mountain ranges are segmented by highlands or mountain passes and valleys. Individual mountains within the same mountain range do not have the same geologic structure or petrology, they may be a mix of different orogenic expressions and terranes, for example thrust sheets, uplifted blocks, fold mountains, volcanic landforms resulting in a variety of rock types. Most geologically young mountain ranges on the Earth's land surface are associated with either the Pacific Ring of Fire or the Alpide Belt.
The Pacific Ring of Fire includes the Andes of South America, extends through the North American Cordillera along the Pacific Coast, the Aleutian Range, on through Kamchatka, Taiwan, the Philippines, Papua New Guinea, to New Zealand. The Andes is 7,000 kilometres long and is considered the world's longest mountain system; the Alpide belt includes Indonesia and Southeast Asia, through the Himalaya, Caucasus Mountains, Balkan Mountains fold mountain range, the Alps, ends in the Spanish mountains and the Atlas Mountains. The belt includes other European and Asian mountain ranges; the Himalayas contain the highest mountains in the world, including Mount Everest, 8,848 metres high and traverses the border between China and Nepal. Mountain ranges outside these two systems include the Arctic Cordillera, the Urals, the Appalachians, the Scandinavian Mountains, the Great Dividing Range, the Altai Mountains and the Hijaz Mountains. If the definition of a mountain range is stretched to include underwater mountains the Ocean Ridges form the longest continuous mountain system on Earth, with a length of 65,000 kilometres.
The mountain systems of the earth are characterized by a tree structure, where mountain ranges can contain sub-ranges. The sub-range relationship is expressed as a parent-child relationship. For example, the White Mountains of New Hampshire and the Blue Ridge Mountains are sub-ranges of the Appalachian Mountains. Equivalently, the Appalachians are the parent of the White Mountains and Blue Ridge Mountains, the White Mountains and the Blue Ridge Mountains are children of the Appalachians; the parent-child expression extends to the sub-ranges themselves: the Sandwich Range and the Presidential Range are children of the White Mountains, while the Presidential Range is parent to the Northern Presidential Range and Southern Presidential Range. The position of mountains influences climate, such as snow; when air masses move up and over mountains, the air cools producing orographic precipitation. As the air descends on the leeward side, it warms again and is drier, having been stripped of much of its moisture.
A rain shadow will affect the leeward side of a range. Mountain ranges are subjected to erosional forces which work to tear them down; the basins adjacent to an eroding mountain range are filled with sediments which are buried and turned into sedimentary rock. Erosion is at work while the mountains are being uplifted until the mountains are reduced to low hills and plains; the early Cenozoic uplift of the Rocky Mountains of Colorado provides an example. As the uplift was occurring some 10,000 feet of Mesozoic sedimentary strata were removed by erosion over the core of the mountain range and spread as sand and clays across the Great Plains to the east; this mass of rock was removed as the range was undergoing uplift. The removal of such a mass from the core of the range most caused further uplift as the region adjusted isostatically in response to the removed weight. Rivers are traditionally believed to be the principal cause of mountain range erosion, by cutting into bedrock and transporting sediment.
Computer simulation has shown that as mountain belts change from tectonically active to inactive, the rate of erosion drops because there are fewer abrasive particles in the water and fewer landslides. Mountains on other planets and natural satellites of the Solar System are isolated and formed by processes such as impacts, though there are examples of mountain ranges somewhat similar to those on Earth. Saturn's moon Titan and Pluto, in particular exhibit large mountain ranges in chains composed of ices rather than rock. Examples include the Mithrim Montes and Doom Mons on Titan, Tenzing Montes and Hillary Montes on Pluto; some terrestrial planets other than Earth exhibit rocky mountain ranges, such as Maxwell Montes on Venus taller than any on Earth and Tartarus Montes on Mars, Jupiter's moon Io has mountain ranges formed from tectonic processes including Boösaule Montes, Dorian Montes, Hi'iaka Montes and Euboea Montes. Peakbagger Ranges Home Page Bivouac.com
A summit is a point on a surface, higher in elevation than all points adjacent to it. The topographic terms acme, apex and zenith are synonymous; the term top is used only for a mountain peak, located at some distance from the nearest point of higher elevation. For example, a big massive rock next to the main summit of a mountain is not considered a summit. Summits near a higher peak, with some prominence or isolation, but not reaching a certain cutoff value for the quantities, are considered subsummits of the higher peak, are considered part of the same mountain. A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top. Summit may refer to the highest point along a line, trail, or route; the highest summit in the world is Everest with height of 8844.43 m above sea level. The first official ascent was made by Sir Edmund Hillary, they reached the mountain`s peak in 1953. Whether a highest point is classified as a summit, a sub peak or a separate mountain is subjective; the UIAA definition of a peak is.
Otherwise, it's a subpeak. In many parts of the western United States, the term summit refers to the highest point along a road, highway, or railroad. For example, the highest point along Interstate 80 in California is referred to as Donner Summit and the highest point on Interstate 5 is Siskiyou Mountain Summit. A summit climbing differs from the common mountaineering. Summit expedition requires: 1+ year of training, a good physical shape, a special gear. Although a huge part of climber’s stuff can be left and taken at the base camps or given to porters, there is a long list of personal equipment. In addition to common mountaineers’ gear, Summit climbers need to take Diamox and bottles of oxygen. There are special requirements for crampons, ice axe, rappel device, etc. Geoid Hill – Landform that extends above the surrounding terrain Nadir Summit accordance Peak finder Summit Climbing Gear List
Yukon is the smallest and westernmost of Canada's three federal territories. It has the smallest population of any province or territory in Canada, with 35,874 people, although it has the largest city in any of the three territories. Whitehorse is Yukon's only city. Yukon was split from the Northwest Territories in 1898 and was named the Yukon Territory; the federal government's Yukon Act, which received royal assent on March 27, 2002, established Yukon as the territory's official name, though Yukon Territory is still popular in usage and Canada Post continues to use the territory's internationally approved postal abbreviation of YT. Though bilingual, the Yukon government recognizes First Nations languages. At 5,959 m, Yukon's Mount Logan, in Kluane National Park and Reserve, is the highest mountain in Canada and the second-highest on the North American continent. Most of Yukon has a subarctic climate, characterized by brief warm summers; the Arctic Ocean coast has a tundra climate. Notable rivers include the Yukon River, as well as the Pelly, Peel and Tatshenshini rivers.
The territory is named after the longest river in Yukon. The name itself is from a contraction of the words in the Gwich'in phrase chųų gąįį han, which means white water river and refers to "the pale colour" of glacial runoff in the Yukon River. Long before the arrival of Europeans and southern Yukon was populated by First Nations people, the area escaped glaciation. Sites of archeological significance in Yukon hold some of the earliest evidence of the presence of human habitation in North America; the sites safeguard the earliest First Nations of the Yukon. The volcanic eruption of Mount Churchill in 800 AD in what is now the U. S. state of Alaska blanketed southern Yukon with a layer of ash which can still be seen along the Klondike Highway, which forms part of the oral tradition of First Nations peoples in Yukon and further south in Canada. Coastal and inland First Nations had extensive trading networks. European incursions into the area began early in the 19th century with the fur trade, followed by missionaries.
By the 1870s and 1880s gold miners began to arrive. This drove a population increase that justified the establishment of a police force, just in time for the start of the Klondike Gold Rush in 1897; the increased population coming with the gold rush led to the separation of the Yukon district from the Northwest Territories and the formation of the separate Yukon Territory in 1898. The territory is the approximate shape of a right triangle, bordering the U. S. state of Alaska to the west and northwest for 1,210 km along longitude 141° W, the Northwest Territories to the east and British Columbia to the south. Its northern coast is on the Beaufort Sea, its ragged eastern boundary follows the divide between the Yukon Basin and the Mackenzie River drainage basin to the east in the Mackenzie mountains. Most of the territory is in the watershed of the Yukon River; the southern Yukon is dotted with a large number of large and narrow glacier-fed alpine lakes, most of which flow into the Yukon River system.
The larger lakes include Teslin Lake, Atlin Lake, Tagish Lake, Marsh Lake, Lake Laberge, Kusawa Lake and Kluane Lake. Bennett Lake on the Klondike Gold Rush trail is a lake flowing into Nares Lake, with the greater part of its area within Yukon. Canada's highest point, Mount Logan, is in the territory's southwest. Mount Logan and a large part of Yukon's southwest are in Kluane National Park and Reserve, a UNESCO World Heritage Site. Other national parks include Ivvavik National Vuntut National Park in the north. Other watersheds include the Mackenzie River, the Peel Watershed and the Alsek–Tatshenshini, a number of rivers flowing directly into the Beaufort Sea; the two main Yukon rivers flowing into the Mackenzie in the Northwest Territories are the Liard River in the southeast and the Peel River and its tributaries in the northeast. Notable widespread tree species within Yukon are white spruce. Many trees are stunted because of severe climate; the capital, Whitehorse, is the largest city, with about three-quarters of the population.
British Columbia Northwest Territories Alaska, United States While the average winter temperature in Yukon is mild by Canadian arctic standards, no other place in North America gets as cold as Yukon during extreme cold snaps. The temperature has dropped down to −60 °C three times, 1947, 1954, 1968; the most extreme cold snap occurred in February 1947 when the abandoned town of Snag dropped down to −63.0 °C. Unlike most of Canada where the most extreme heat waves occur in July and September, Yukon's extreme heat tends to occur in June and May. Yukon has recorded 36 °C three times; the first time was in June 1969 when Mayo recorded a temperature of 36.1 °C. 14 years this record was beaten when Forty Mile recorded 36 °C in May 1983. The old record was broken 21 years in June 2004 when the Mayo Road weather station, located just northwest of Whitehorse, recorded a temperature of 36.5 °C. The 2016 census reported a Yukon population of 35,874, an increase of 5.8% from 2011. With a land area of 474,712.64 km2, it had a population de
The Ogilvie Mountains are a mountain range in the Yukon Territory of northwestern Canada. Geologically they are part of the Yukon Ranges, in the upper Laramide Belt of the North American Cordillera; the range lies north of Dawson City, is crossed by the Dempster Highway. The area was first surveyed by the range subsequently named after him. Sub-rangesNahoni Range The best known mountain peaks of the Ogilvie Mountains are located within Tombstone Territorial Park; the highest mountain within the range is Mount Frank Rae, at 2,362 m in elevation. The range's most familiar mountains, with their jagged granite peaks, are: Tombstone Mountain Mount Monolith Canadian Mountain Encyclopedia: Ogilvie Mountains
Dawson City the Town of the City of Dawson, is a town in the Canadian territory of Yukon. It is inseparably linked to the Klondike Gold Rush, its population was 1,375 as of the 2016 census. Making it the second largest town of Yukon. In prehistoric times the area was used for agriculture by the Hän-speaking people of the Tr’ondëk Hwëch’in and their forebears; the heart of their homeland was Tr'ochëk, a fishing camp at the confluence of the Klondike River and Yukon River, now a National Historic Site of Canada, just across the Klondike River from modern Dawson City. This site was an important summer gathering spot and a base for moose-hunting on the Klondike Valley; the current settlement was founded by Joseph Ladue and named in January 1897 after noted Canadian geologist George M. Dawson, who had explored and mapped the region in 1887, it served as Yukon's capital from the territory's founding in 1898 until 1952, when the seat was moved to Whitehorse. Dawson City was the centre of the Klondike Gold Rush.
It began in 1896 and changed the First Nations camp into a thriving city of 40,000 by 1898. By 1899, the gold rush had ended and the town's population plummeted as all but 8,000 people left; when Dawson was incorporated as a city in 1902, the population was under 5,000. St. Paul's Anglican Church built; the population dropped after World War II when the Alaska Highway bypassed it 300 miles to the south. The economic damage to Dawson City was such that Whitehorse, the highway's hub, replaced it as territorial capital in 1953. Dawson City's population languished around the 600–900 mark through the 1960s and 1970s, but has risen and held stable since then; the high price of gold has made modern placer mining operations profitable, the growth of the tourism industry has encouraged development of facilities. In the early 1950s, Dawson was linked by road to Alaska, in fall 1955, with Whitehorse along a road that now forms part of the Klondike Highway. In 1978, another kind of buried treasure was discovered when a construction excavation inadvertently uncovered a forgotten collection of more than 500 discarded films on flammable nitrate film stock from the early 20th century that were buried in the permafrost.
These silent-era film reels, dating from "between 1903 and 1929, were uncovered in the rubble beneath old hockey rink". Owing to its dangerous chemical volatility, the historical find was moved by military transport to Library and Archives Canada and the U. S. Library of Congress for both transfer to safety film and storage. A documentary about the find, Dawson City: Frozen Time was released in 2016; the City of Dawson and the nearby ghost town of Forty Mile are featured prominently in the novels and short stories of American author Jack London, including The Call of the Wild. London lived in the Dawson area from October 1897 to June 1898. Other writers who lived in and wrote of Dawson City include Pierre Berton and the poet Robert Service; the childhood home of the former is now used as a retreat for professional writers administered by the Writers' Trust of Canada. Dawson City lies on the Tintina Fault; this fault continues eastward for several hundred kilometres. Erosional remnants of lava flows form outcrops north and west of Dawson City.
Like most of Yukon, Dawson City has a subarctic climate. The average temperature in July is 15.7 °C and in January is −26.0 °C. The highest temperature recorded is 35.0 °C on 9 July 1899 and 18 June 1950. The lowest temperature recorded is −58.3 °C on 3 February 1947. It experiences a wide range of temperatures surpassing 30 °C in most summers and dropping below −40 °C in winter; the community is at an elevation of 320 m and the average rainfall in July is 49.0 mm and the average snowfall in January is 27.6 cm. Dawson has averages 70 frost free days per year; the town is built on a layer of frozen earth, which may pose a threat to the town's infrastructure in the future if the permafrost melts. Dawson was incorporated as a city in 1902 when it met the criteria for "city" status under the municipal act of that time, it retained the incorporation as the population plummeted. When a new municipal act was adopted in the 1980s, Dawson met the criteria of "town", was incorporated as such although with a special provision to allow it to continue to use the word "City" for historical reasons and to distinguish it from Dawson Creek, a small city in northeastern British Columbia.
Dawson Creek is named in honour of George M. Dawson; this led the territorial government to post the following signs at the boundaries of the town: "Welcome to the Town of the City of Dawson". In 2004, the Yukon government removed the mayor and the town council, as a result of the town going bankrupt; the territorial government accepted a large portion of the responsibility for this situation in March 2006, writing off $3.43 million of the debt and leaving the town with $1.5 million still to pay off. Elections were set for June 15, 2006. John Steins, a local artist and one of the leaders of the movement to restore democracy to Dawson, was acclaimed as mayor, while 13 residents ran for the four council seats. Steins was succeeded in office by former mayor Peter Jenkins, who in turn was succeeded by the current mayor, Wayne Potoroka. Other past mayors of Dawson City have included Art Webster, Colin Mayes, Yolanda Burkhard, Mike Comadain and Vi Campbell. In the Legislative Assembly of Yukon, Dawson City is in the electoral district of Klondike represented by Sandy Silver of the Yukon Liberal Party.
The government of Tr’ond
In modern mapping, a topographic map is a type of map characterized by large-scale detail and quantitative representation of relief using contour lines, but using a variety of methods. Traditional definitions require a topographic map to show both man-made features. A topographic survey is published as a map series, made up of two or more map sheets that combine to form the whole map. A contour line is a line connecting places of equal elevation. Natural Resources Canada provides this description of topographic maps:These maps depict in detail ground relief, forest cover, administrative areas, populated areas, transportation routes and facilities, other man-made features. Other authors define topographic maps by contrasting them with another type of map. However, in the vernacular and day to day world, the representation of relief is popularly held to define the genre, such that small-scale maps showing relief are called "topographic"; the study or discipline of topography is a much broader field of study, which takes into account all natural and man-made features of terrain.
Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms; this is in contrast to older cadastral surveys, which show property and governmental boundaries. The first multi-sheet topographic map series of an entire country, the Carte géométrique de la France, was completed in 1789; the Great Trigonometric Survey of India, started by the East India Company in 1802 taken over by the British Raj after 1857 was notable as a successful effort on a larger scale and for determining heights of Himalayan peaks from viewpoints over one hundred miles distant. Topographic surveys were prepared by the military to assist in planning for battle and for defensive emplacements; as such, elevation information was of vital importance. As they evolved, topographic map series became a national resource in modern nations in planning infrastructure and resource exploitation. In the United States, the national map-making function, shared by both the Army Corps of Engineers and the Department of the Interior migrated to the newly created United States Geological Survey in 1879, where it has remained since.1913 saw the beginning of the International Map of the World initiative, which set out to map all of Earth's significant land areas at a scale of 1:1 million, on about one thousand sheets, each covering four degrees latitude by six or more degrees longitude.
Excluding borders, each sheet was up to 66 cm wide. Although the project foundered, it left an indexing system that remains in use. By the 1980s, centralized printing of standardized topographic maps began to be superseded by databases of coordinates that could be used on computers by moderately skilled end users to view or print maps with arbitrary contents and scale. For example, the Federal government of the United States' TIGER initiative compiled interlinked databases of federal and local political borders and census enumeration areas, of roadways and water features with support for locating street addresses within street segments. TIGER was used in the 1990 and subsequent decennial censuses. Digital elevation models were compiled from topographic maps and stereographic interpretation of aerial photographs and from satellite photography and radar data. Since all these were government projects funded with taxes and not classified for national security reasons, the datasets were in the public domain and usable without fees or licensing.
TIGER and DEM datasets facilitated Geographic information systems and made the Global Positioning System much more useful by providing context around locations given by the technology as coordinates. Initial applications were professionalized forms such as innovative surveying instruments and agency-level GIS systems tended by experts. By the mid-1990s user-friendly resources such as online mapping in two and three dimensions, integration of GPS with mobile phones and automotive navigation systems appeared; as of 2011, the future of standardized, centrally printed topographical maps is left somewhat in doubt. Topographic maps have multiple uses in the present day: any type of geographic planning or large-scale architecture; the various features shown on the map are represented by conventional symbols. For example, colors can be used to indicate a classification of roads; these signs are explained in the margin of the map, or on a separately published characteristic sheet. Topographic maps are commonly called contour maps or topo maps.
In the United States, where the primary national series is organized by a strict 7.5-minute grid, they are called topo quads or quadrangles. Topographic maps conventionally show land contours, by means of contour lines. Contour lines are curves. In other words, every point on the marked line of 100 m elevation is 100 m above mean sea level; these maps show