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
Denali is the highest mountain peak in North America, with a summit elevation of 20,310 feet above sea level. With a topographic prominence of 20,156 feet and a topographic isolation of 4,629 miles, Denali is the third most prominent and third most isolated peak on Earth, after Mount Everest and Aconcagua. Located in the Alaska Range in the interior of the U. S. state of Alaska, Denali is the centerpiece of Preserve. The Koyukon people who inhabit the area around the mountain have referred to the peak as "Denali" for centuries. In 1896, a gold prospector named it "Mount McKinley" in support of then-presidential candidate William McKinley. In August 2015, following the 1975 lead of the State of Alaska, the United States Department of the Interior announced the change of the official name of the mountain to Denali. In 1903, James Wickersham recorded the first attempt at climbing Denali, unsuccessful. In 1906, Frederick Cook claimed the first ascent, proven to be false; the first verifiable ascent to Denali's summit was achieved on June 7, 1913, by climbers Hudson Stuck, Harry Karstens, Walter Harper, Robert Tatum, who went by the South Summit.
In 1951, Bradford Washburn pioneered the West Buttress route, considered to be the safest and easiest route, therefore the most popular in use. On September 2, 2015, the U. S. Geological Survey announced that the mountain is 20,310 feet high, not 20,320 feet, as measured in 1952 using photogrammetry. Denali is a granitic pluton lifted by tectonic pressure from the subduction of the Pacific Plate beneath the North American Plate; the forces that lifted Denali cause many deep earthquakes in Alaska and the Aleutian Islands. The Pacific Plate is seismically active beneath Denali, a tectonic region, known as the "McKinley cluster". Denali has a summit elevation of 20,310 feet above sea level, making it the highest peak in North America and the northernmost mountain above 6,000 meters elevation in the world. Measured from base to peak at some 18,000 ft, it is among the largest mountains situated above sea level. Denali rises from a sloping plain with elevations from 1,000 to 3,000 ft, for a base-to-peak height of 17,000 to 19,000 ft.
By comparison, Mount Everest rises from the Tibetan Plateau at a much higher base elevation. Base elevations for Everest range from 13,800 ft on the south side to 17,100 ft on the Tibetan Plateau, for a base-to-peak height in the range of 12,000 to 15,300 ft. Denali's base-to-peak height is little more than half the 33,500 ft of the volcano Mauna Kea, which lies under water. Denali has two significant summits: the South Summit is the higher one, while the North Summit has an elevation of 19,470 ft and a prominence of 1,270 ft; the North Summit is sometimes counted as sometimes not. Five large glaciers flow off the slopes of the mountain; the Peters Glacier lies on the northwest side of the massif, while the Muldrow Glacier falls from its northeast slopes. Just to the east of the Muldrow, abutting the eastern side of the massif, is the Traleika Glacier; the Ruth Glacier lies to the southeast of the mountain, the Kahiltna Glacier leads up to the southwest side of the mountain. With a length of 44 mi, the Kahiltna Glacier is the longest glacier in the Alaska Range.
The Koyukon Athabaskans who inhabit the area around the mountain have for centuries referred to the peak as Dinale or Denali. The name is based on a Koyukon word for "high" or "tall". During the Russian ownership of Alaska, the common name for the mountain was Bolshaya Gora, the Russian translation of Denali, it was called Densmore's Mountain in the late 1880s and early 1890s after Frank Densmore, an Alaskan prospector, the first European to reach the base of the mountain. In 1896, a gold prospector named it McKinley as political support for then-presidential candidate William McKinley, who became president the following year; the United States formally recognized the name Mount McKinley after President Wilson signed the Mount McKinley National Park Act of February 26, 1917. In 1965, Lyndon B. Johnson declared the north and south peaks of the mountain the "Churchill Peaks", in honor of British statesman Winston Churchill; the Alaska Board of Geographic Names changed the name of the mountain to Denali in 1975, how it is called locally.
However, a request in 1975 from the Alaska state legislature to the United States Board on Geographic Names to do the same at the federal level was blocked by Ohio congressman Ralph Regula, whose district included McKinley's hometown of Canton. On August 30, 2015, just ahead of a presidential visit to Alaska, the Barack Obama administration announced the name Denali would be restored in line with the Alaska Geographic Board's designation. U. S. Secretary of the Interior Sally Jewell issued the order changing the name to Denali on August 28, 2015, effective immediately. Jewell said the change had been "a long time coming"; the renaming of the mountain received praise from Alaska's senior U. S. senator, Lisa Murkowski, who had introduced legislation to accomplish the name change, but it drew criticism from several politicians from Pres
Bishop is a city in Inyo County, United States. Though Bishop is the only incorporated city and the largest populated place in Inyo County, the county seat is located in Independence. Bishop is located at an elevation of 4,150 feet; the town was named after Bishop Creek. Located near numerous tourist attractions, Bishop is a major resort town; the population of the city was 3,879 at the 2010 census, up from 3,575 at the 2000 census. The population of the built-up zone containing Bishop is much larger, however. More than 14,500 people live in a compact area that includes Bishop, West Bishop, Dixon Lane-Meadow Creek, the Bishop Reservation, it is by far the largest settlement in Inyo County. A number of western films were shot in Bishop, including movies starring John Wayne, Charlton Heston and Joel McCrea. Bishop lies west of the Owens River at the northern end of the Owens Valley, it is on U. S. Route 395, the main north-south artery through the Owens Valley, connecting the Inland Empire to Reno, Nevada.
US 395 connects Bishop to Los Angeles via State Route 14 through Palmdale. Bishop is the western terminus of U. S. Route 6; the Paiute-Shoshone Indians of the Bishop Community of the Bishop Colony control land just west of the town. The Los Angeles Department of Water and Power controls much of the upstream and surrounding area. Bishop is to the east of the Sierra Nevada, west of the White Mountains. Numerous peaks are within a short distance of Bishop, including Mount Humphreys, to the west, White Mountain Peak in the northeast, pyramidal Mount Tom northwest of town. Basin Mountain is viewed to the west from Bishop. According to the United States Census Bureau, the city has a total area of 1.9 square miles, over 97% of it land. Bishop is known as the "Mule Capital of the World" and a week-long festival called Bishop Mule Days has been held since 1969 on the week of Memorial Day, celebrating the contributions of pack mules to the area; the festival attracts many tourists from the Southern California area.
Bishop is well known in the rock climbing community. Near the city are numerous climbing spots that attract visitors from around the world. There are over 2,000 bouldering problems in Bishop; the two main types of rock are volcanic granite. Bishop Visitors Bureau Bishop Area Chamber of Commerce City of Bishop Inyo National Forest Supervisor's Office Paiute Indian Reservation Paiute-Shoshone Cultural Center Museum Laws Rail Museum Keoughs Hot Springs Eastern Sierra Regional Airport Ancient Bristlecone Pine Forest The City of Bishop in Inyo County, California was named for one of the first European settlers in the area, Samuel A. Bishop. Owens Lake was named for Richard Owens, a member of John C. Fremont's 1845 exploration party which included Ed Kern; the entire valley became known as The Owens Valley. The Paiute Indians called Owens Lake by the name of “Pacheta” and the Owens River “Wakopee.” Geographically, Inyo County is today the second largest county in California with a population of over 18,000 residents.
The county is so big that several eastern states put together would fit neatly within its boundaries. Inyo County contains the lowest points in the contiguous United States. A difference of nearly 15,000 feet; the “Inyo” in Inyo County is believed to be a Paiute word meaning “dwelling place of the great spirit,” although some scholars are now convinced that it is a mistranslation of the word, “Indio,” Spanish for Indian. It is possible that the Paiute were trying to explain to the earliest English speaking settlers in the Owens Valley that this was their land by using a form of “Indio” they had learned from other Indian tribes, who in turn, had learned it from the Spanish or Mexicans, not realizing that not all Europeans spoke the same language, thus Inyo may mean “Indian Land.” The first American explorers in the Owens Valley of Eastern California included the famous mountain men Jedediah Smith in 1826 and Joseph Walker in 1834. This remote area of California had never been explored by the Spanish and though it was shown as Mexican territory on early maps, the Eastern Sierra region remained unvisited by them.
Present day Walker Lake in western Nevada, the Walker River on the California/Nevada border and Walker Pass in the southern Sierra were named for their discoverer, Joseph Walker. The most renowned early explorer to visit the area was John C. Fremont, he was the first Republican candidate to run for President of the United States in 1856 and a famous Union Civil War general. Sanctioned by the federal government, his 1845 mapping party to the Eastern Sierra included the celebrated Indian scout Kit Carson, for whom the capitol of Nevada, Carson City, was named. In the party were Ed Kern for whom Kern County, California was named, Richard Owens, who gave his name to the Owens Lake near Lone Pine and the Owens Valley itself. Fremont lost a cannon that he had brought along in case of Indian attacks somewhere near present day Bridgeport, California. Someone will stumble across the rusty old cannon someday; the City of Bishop came into being due to the need for beef in a booming mining camp some eighty miles to the north, Nevada, (Aurora w
A combat engineer is a soldier who performs a variety of construction and demolition tasks under combat conditions. The combat engineer's goals involve facilitating movement and support of friendly forces while impeding those of the enemy. Combat engineers build fighting positions and roads, they conduct clear minefields using specialized vehicles. Typical combat engineer missions include construction and breaching of trenches, tank traps and other fortifications. A combat engineer is trained as an infantryman, combat engineer units have a secondary role fighting as infantry. A general combat engineer is called a pioneer or sapper, terms derived from the French and British armies. In some armies and sapper indicate specific military ranks and levels of combat engineers, who work under fire in all seasons, may be allocated to different corps, as they were in the former Soviet Army, or they may be organized in the same corps. Geomatics is another area of military engineering but is performed by the combat engineers of some nations and in other cases is a separate responsibility, as was the case in the Australian Army.
While the officers of a combat engineering unit may be professionally certified civil or mechanical engineers, the non-commissioned members are not. Sapper: In the U. S. British, Canadian and New Zealand armies, is a soldier who has specialized combat engineer training. In the Israeli Defence Forces, Sapper is a military profession code denoting a combat engineer who has graduated from various levels of combat engineering training. Sapper 05 is the basic level, Sapper 06 is the general level, Sapper 08 is the combat engineer commander's level and Sapper 11 is the combat engineer officer level. All IDF sappers are trained as Rifleman 07, matching infantry. In the Canadian Army, is a term for soldiers that have completed the basic Combat Engineer training. In the Portuguese Army, a sapador de engenharia is a soldier of the engineering branch that has specialized combat engineer training. A sapador de infantaria is a soldier of the infantry branch that has a similar training and that serves in the combat support sapper platoon of an infantry battalion.
The Italian Army uses the term "Guastatori" for their combat engineers. Pioneer: In the Finnish army, pioneeri is the private equivalent rank in the army for a soldier who has completed the basic combat engineering training. Naval engineers bear the pioneeri insignia on their sleeves; the German Bundeswehr uses the term "Pionier" for their combat engineers and other specialized units, who are associated with Special Forces to clear obstacles and perform engineering duties. The combat engineers in the Austro-Hungarian k.u.k. Forces were called "Pioniere". Assault pioneer: In the British and Australian armies, an assault pioneer is an infantry soldier with some limited combat engineer training in clearing obstacles during assaults and light engineering duties; until assault pioneers were responsible for the operation of flamethrowers. Field engineer: is a term used in many Commonwealth armies. In modern usage, it is synonymous with "combat engineer". However, the term identified those military engineers who supported an army operating in the field as opposed to garrison engineers who built and supported permanent fix bases.
In its original usage, "field engineering" would have been inclusive of but broader than "combat engineering." Miner Pontonier Combat engineers are force multipliers and enhance the survival of other troops through the use and practice of camouflage, reconnaissance and other services. These include the construction of roads, field fortifications and the construction and running of water points. In these roles, combat engineers use a wide variety of power tools, they are responsible for construction rigging, the use of explosives, the carrying out of demolitions, obstacle clearance, obstacle construction, assault of fortifications, use of assault boats in water obstacle crossings, helipad construction, general construction, route reconnaissance and road reconnaissance, erecting communication installations. Combat engineers build and run water distribution points, carrying out water filtration, NBC decontamination when necessary, storage prior to distribution. All these role activities and technologies are divided into several areas of combat engineering: Mobility Improving the ability of one's own force to move around the battlefield.
Combat engineers support this role through reduction of enemy obstacles which include point and row minefields, anti-tank ditches, wire obstacles and metal anti-vehicle barriers, Improvised Explosive Devices and wall and door breaching in urban terrain. Mechanized combat engineer units have armored vehicles capable of laying short bridges for limited gap-crossing. Clearing terrain obstacles Overcoming trenches and ditches Opening routes for armored fighting vehicles Constructing roads and bridges Route clearanceCountermobility Building obstacles to prevent the enemy from moving around the battlefield. Destroying bridges, blocking roads, creating airstrips, digging trenches, etc. Can include planting land mines and anti-handling devices when authorized and directed to do so; when the defender must retreat it is desirable to destroy anything that may be of use to the enem
Francis P. Farquhar
Francis Peloubet Farquhar was an American mountaineer and author in addition to his career as a Certified Public Accountant. Farquhar was born in Newton, the son of David Webber Farquhar and Grace Thaxter Peloubet, he attended Harvard University, where he edited The Harvard Crimson for three years and studied under, among others, Bliss Perry and George Santayana. Graduating from Harvard in 1909, he came to San Francisco in 1910, where he worked for a publisher and began a lifelong interest in fine printing, he visited Yosemite and joined the Sierra Club in 1911. He returned to New England to pursue the profession of accounting, studying under Clinton Scovell, a pioneer in the field of cost accounting. In 1914 he moved again to California, he served in the Navy there and in Washington, D. C. during World War I. In 1922 he set up his own accounting firm in San Francisco. In 1936 he brought in Clifford Heimbuchder, who soon became a full partner in the firm, renamed Farquhar and Heimbucher. Farquhar was active in the Sierra Club, serving on its board of directors from 1924 to 1951 and president in 1933-1935 and 1948-1949.
He served as Sierra Club Bulletin editor from 1926 to 1946. Farquhar was a mountaineer who invited Robert L. M. Underhill to introduce proper use of modern Alpine rope techniques to Sierra Club members on an annual club High Trip in 1931, he made multiple first ascents. On August 26, 1921, he completed the first ascent of Middle Palisade by the south-west chute with Ansel Hall, he was the author of numerous articles for the Sierra Club and the California Historical Society, some of which were reprinted in book form. In 1956-59 he was editor of the American Alpine Journal published by the American Alpine Club, he wrote forewords for several books on California history. His best known book is History of the Sierra Nevada, still in print. In addition to serving as Sierra Club president, he was president of the California Society of Certified Public Accountants, California Academy of Sciences, the California Historical Society. In 1965 he was awarded the Sierra Club's John Muir Award for distinguished work as a conservationist and mountaineer.
He received the Henry R. Wagner Memorial Award of the California Historical Society in 1966; the University of California at Los Angeles conferred on him the honorary degree of Doctor of Humane Letters in 1967. In 1934 he married fellow mountaineer, his half brother was the Los Angeles architect Robert D. Farquhar, who moved in with the Farquhars in Berkeley in 1953. Marjorie Bridge Farquhar died in 1999 in San Francisco. Mount Farquhar, located 1.6 miles northwest of Mount Brewer in Kings Canyon National Park, was named in his honor. Since 1970, the Sierra Club has given the Francis P. Farquhar Mountaineering Award in his honor. 1925: Exploration of the Sierra Nevada, California Historical Society 1926: Place Names of the High Sierra, Sierra Club 1930: Up and Down California in 1860-1864: The Journal of William H. Brewer, University of California Press 1932: Joaquin Murieta, the Brigand Chief of California, Grabhorn Press, San Francisco 1938: Preface to Clarence King's The Helmet of Mambrino, The Book Club of California 1943: A Brief Chronology of Discovery in the Pacific Ocean from Balboa to Capt.
Cook's First Voyage, 1513 to 1770, Grabhorn Press, San Francisco 1947: Preface and editing, Clarence King's Mountaineering in the Sierra Nevada 1948: Yosemite, the Big Trees and the High Sierra: A Selective Bibliography, University of California Press, ISBN 978-1-57898-155-7 1950: Flight to the North Pole, 24 August 1949, Grabhorn Press 1953: First Ascents Throughout the World, 1901-1950, Grabhorn Press 1953: The Books of the Colorado River & the Grand Canyon, Fretwater Press, ISBN 978-1-892327-14-7 1957: Place Names for Bohemians: Clubhouse to Grove, Silverado Squatters 1959: Naming Alaska's mountains: with some accounts of their first ascents, American Alpine Club 1965: History of the Sierra Nevada, University of California Press, Berkeley, ISBN 0-520-01551-7 1968: "Comments on Some Bay Area Fine Printers" in Edwin Grabhorn: Recollections of the Grabhorn Press, University of California, Bancroft Library, Regional Oral History Office Francis Farquhar Obituary Francis P. Farquhar, Exploration of the Sierra Nevada Francis P. Farquhar, Place Names of the High Sierra Guide to the Francis P. Farquhar Papers at The Bancroft Library Portrait Photo on Mt. Whitney Francis P. Farquhar at Find a Grave
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
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