Atmospheric pressure
Atmospheric pressure, sometimes called barometric pressure, is the pressure within the atmosphere of Earth. The standard atmosphere is a unit of pressure defined as 1013.25 mbar, equivalent to 760 mmHg, 29.9212 inches Hg, or 14.696 psi. The atm unit is equivalent to the mean sea-level atmospheric pressure on Earth, that is, the Earth's atmospheric pressure at sea level is 1 atm. In most circumstances atmospheric pressure is approximated by the hydrostatic pressure caused by the weight of air above the measurement point; as elevation increases, there is less overlying atmospheric mass, so that atmospheric pressure decreases with increasing elevation. Pressure measures force per unit area, with SI units of Pascals. On average, a column of air with a cross-sectional area of 1 square centimetre, measured from mean sea level to the top of Earth's atmosphere, has a mass of about 1.03 kilogram and exerts a force or "weight" of about 10.1 newtons or 2.37 lbf, resulting in a pressure at sea level of about 10.1 N/cm2 or 101 kN/m2.
A column of air with a cross-sectional area of 1 in2 would have a mass of about 6.65 kg and a weight of about 65.4 N or 14.7 lbf, resulting in a pressure of 10.1 N/cm2 or 14.7 lbf/in2. Atmospheric pressure is caused by the gravitational attraction of the planet on the atmospheric gases above the surface, is a function of the mass of the planet, the radius of the surface, the amount and composition of the gases and their vertical distribution in the atmosphere, it is modified by the planetary rotation and local effects such as wind velocity, density variations due to temperature and variations in composition. The mean sea-level pressure is the average atmospheric pressure at mean sea level; this is the atmospheric pressure given in weather reports on radio and newspapers or on the Internet. When barometers in the home are set to match the local weather reports, they measure pressure adjusted to sea level, not the actual local atmospheric pressure; the altimeter setting in aviation is an atmospheric pressure adjustment.
Average sea-level pressure is 1013.25 mbar. In aviation, weather reports, QNH is transmitted around the world in millibars or hectopascals, except in the United States and Colombia where it is reported in inches of mercury; the United States and Canada report sea-level pressure SLP, adjusted to sea level by a different method, in the remarks section, not in the internationally transmitted part of the code, in hectopascals or millibars. However, in Canada's public weather reports, sea level pressure is instead reported in kilopascals. In the US weather code remarks, three digits are all; the highest sea-level pressure on Earth occurs in Siberia, where the Siberian High attains a sea-level pressure above 1050 mbar, with record highs close to 1085 mbar. The lowest measurable sea-level pressure is found at the centers of tropical cyclones and tornadoes, with a record low of 870 mbar. Surface pressure is the atmospheric pressure at a location on Earth's surface, it is directly proportional to the mass of air over that location.
For numerical reasons, atmospheric models such as general circulation models predict the nondimensional logarithm of surface pressure. The average value of surface pressure on Earth is 985 hPa; this is in contrast to mean sea-level pressure, which involves the extrapolation of pressure to sea-level for locations above or below sea-level. The average pressure at mean sea-level in the International Standard Atmosphere is 1013.25 hPa, or 1 atmosphere, or 29.92 inches of mercury. Pressure and the acceleration due to gravity, are related by P = F/A = /A, where A is surface area. Atmospheric pressure is thus proportional to the weight per unit area of the atmospheric mass above that location. Pressure on Earth varies with the altitude of the surface. Pressure varies smoothly from the Earth's surface to the top of the mesosphere. Although the pressure changes with the weather, NASA has averaged the conditions for all parts of the earth year-round; as altitude increases, atmospheric pressure decreases.
One can calculate the atmospheric pressure at a given altitude. Temperature and humidity affect the atmospheric pressure, it is necessary to know these to compute an accurate figure; the graph at right was developed for a temperature of 15 °C and a relative humidity of 0%. At low altitudes above sea level, the pressure decreases by about 1.2 kPa for every 100 metres. For higher altitudes within the troposphere, the following equation relates atmospheric pressure p to altitude h p = p 0 ⋅ g ⋅ M R 0 ⋅
United States National Grassland
National Grassland is a classification of protected and managed federal lands in the United States authorized by Title III of the Bankhead–Jones Farm Tenant Act of 1937. For administrative purposes, they are identical to United States National Forests, except that grasslands are areas consisting of prairie. Like National Forests, National Grasslands may be open for hunting, mineral extraction and other uses. Various National Grasslands are administered in conjunction with nearby National Forests. All but three National Grasslands are at the edge of the Great Plains; those three are in southeastern Idaho, northeastern California, central Oregon. The three National Grasslands in North Dakota, together with one in northwestern South Dakota, are administered jointly as the Dakota Prairie Grasslands. National Grasslands are much smaller than National Forests. Whereas a typical National Forest would be about 1,000,000 acres, the average Grassland size is 191,914 acres; the largest National Grassland, the Little Missouri National Grassland in North Dakota, covers 1,028,784 acres, the median size of a National Forest.
As of September 30, 2007, the total area of all 20 National Grasslands was 3,838,280 acres. The catastrophic Dust Bowl of the 1930s led to the creation of the Soil Conservation Service in 1933; this and subsequent federal laws paved the way for establishing national grasslands. Grassland Prairie Temperate grasslands and shrublands List of U. S. National Forests Wilderness preservation systems in the United States
Black Hills National Forest
Black Hills National Forest is located in southwestern South Dakota and northeastern Wyoming, United States. The forest is managed by the Forest Service. Forest headquarters are located in South Dakota. There are local ranger district offices in Custer, Rapid City, Spearfish in South Dakota, in Sundance, Wyoming. Predominantly ponderosa pine, the forest includes hard woods like aspen, bur oak, birch; the lower elevations include grassland prairie, but the National Forest System lands encompass most of the mountainous region known as the Black Hills of South Dakota and Wyoming. Within the forest is Black Elk Peak, the tallest mountain in South Dakota and the highest peak east of the Rocky Mountains in the United States. After a series of devastating wildfires in 1893, U. S. President Grover Cleveland created the Black Hills Forest Reserve on February 22, 1897. U. S. President William McKinley issued a presidential proclamation on September 19, 1898 appending the Black Hills Forest Reserve geographic boundaries while acknowledging the forest preservation decrees established by the Timber Culture Act and Forest Reserve Act of 1891.
Upon the creation of the Forest Service in 1905, the reserve was transferred to the new agency under the United States Department of Agriculture and redesignated as a National Forest two years later. Lakota words pahá sápa meaning "hills that are black" may be one of the factors in the regions naming. Early settlers and explorers called the Laramie Range the Black Hills prior to Lt. G. K. Warren's expedition in 1857. Prior to explorations by the La Verendrye brothers in 1742, many tribes frequented the Black Hills including Ponca, Kiowa Apache, Arapaho and Cheyenne for at least the past 10,000 years; the smallpox epidemics of 1771 to 1781 broke the will of the Arikara who prior to that time held the Sioux east of the Missouri. American Horse's winter count of 1775-76 is interpreted as depicting the Sioux discovery of the Black Hills; the mountains and other key features in and around the Black Hills and now within the Forest were considered sacred to indigenous peoples and many came here on vision quests, for hunting and for trade.
The forest is located in parts of seven counties in South Wyoming. In descending order of forestland area they are Pennington, Lawrence, Fall River and Weston counties; the Forest is located west and south of Rapid City and can be accessed from Interstate 90. The forest headquarters is located in South Dakota; the Peter Norbeck National Scenic Byway passes through the forest in proximity to Mount Rushmore and along with the Spearfish Canyon National Forest Scenic Byway, provide two of the more scenic drives in the Country. Although surrounded by Black Hills National Forest, both Jewel Cave National Monument and Mount Rushmore National Memorial are separate areas administered by the National Park Service. Wind Cave National Park, another area administered by the National Park Service, borders portions of the forest in the southeast. Black Elk Wilderness is a wilderness within the Forest and no motorized transport is permitted. Outside of the wilderness, mining and ranching are permitted on public lands through land leases with companies and private parties, referred to as "permittees."
The Black Hills National Forest encompasses three distinct mountain ranges: the Black Hills and the Elk Mountains in South Dakota as well as the Bear Lodge Mountains in Wyoming. The Black Hills are by far the largest of the three ranges. While ponderosa pine is the most common tree species found in the forest, spruce can be found in the higher elevations. Elk, mule deer and white-tailed deer are seen. Black bears have been spotted in the Black Hills. Cougars are increasing as a result of prolific herds of deer and elk. Coyotes, bighorn sheep and mountain goats are frequently seen by visitors. Bald eagles, osprey, peregrine falcon and another two hundred species of birds can be found in this forest along streams and near water sources. 30 campgrounds are located in the forest and there are 11 reservoirs that are well stocked for sport fishing. 450 miles of hiking trails provide access to more remote destinations and to the summit of Black Elk Peak. With over 5,000 miles of Forest system roads, the Forest is a haven for motorized travel.
Black Hills National Forest travel guide from Wikivoyage "Black Hills National Forest". U. S. Forest Service
Natural monument
A natural monument is a natural or natural/cultural feature of outstanding or unique value because of its inherent rarity, representative of aesthetic qualities or cultural significance. Under World Commission on Protected Areas guidelines, natural monuments are level III, described as: "Areas are set aside to protect a specific natural monument, which can be a landform, sea mount, submarine cavern, geological feature such as a cave or a living feature such as an ancient grove, they are quite small protected areas and have high visitor value."This is a lower level of protection than level II and level I. The European Environment Agency's guidelines for selection of a natural monument are: The area should contain one or more features of outstanding significance. Appropriate natural features include waterfalls, craters, fossil beds, sand dunes and marine features, along with unique or representative fauna and flora; the area should be large enough to protect the integrity of the feature and its related surroundings.
Natural monument signs selection IUCN Protected Area Management Categories: Category III Natural Monument or Feature U. S. National Monument World Conservation Union A-Z of Areas of Biodiversity Importance: Natural Monument or Feature Natural Monuments in Brazil
United States
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
Mammoth Cave National Park
Mammoth Cave National Park is an American national park in central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world. Since the 1972 unification of Mammoth Cave with the even-longer system under Flint Ridge to the north, the official name of the system has been the Mammoth–Flint Ridge Cave System; the park was established as a national park on July 1, 1941, a World Heritage Site on October 27, 1981, an international Biosphere Reserve on September 26, 1990. The park's 52,830 acres are located in Edmonson County, with small areas extending eastward into Hart and Barren counties; the Green River runs through the park, with a tributary called the Nolin River feeding into the Green just inside the park. Mammoth Cave is the world's longest known cave system with more than 400 miles of surveyed passageways, nearly twice as long as the second-longest cave system, Mexico's Sac Actun underwater cave. Mammoth Cave developed in thick Mississippian-aged limestone strata capped by a layer of sandstone, which has made the system remarkably stable.
It is known to include more than 400 miles of passageway. Mammoth Cave National Park was established to preserve the cave system; the upper sandstone member is known as the Big Clifty Sandstone. Thin, sparse layers of limestone interspersed within the sandstones give rise to an epikarstic zone, in which tiny conduits are dissolved by the natural acidity of groundwater; the epikarstic zone concentrates local flows of runoff into high-elevation springs which emerge at the edges of ridges. The resurgent water from these springs flows on the surface before sinking underground again at elevation of the contact between the sandstone caprock and the underlying massive limestones, it is in these underlying massive limestone layers that the human-explorable caves of the region have developed. The limestone layers of the stratigraphic column beneath the Big Clifty, in increasing order of depth below the ridgetops, are the Girkin Formation, the Ste. Genevieve Limestone, the St. Louis Limestone. For example, the large Main Cave passage seen on the Historic Tour is located at the bottom of the Girkin and the top of the Ste.
Genevieve Formation. Each of the primary layers of limestone subunits. One area of cave research involves correlating the stratigraphy with the cave survey produced by explorers; this makes it possible to produce approximate three-dimensional maps of the contours of the various layer boundaries without the necessity for test wells and extracting core samples. The upper sandstone caprock is hard for water to penetrate: the exceptions are where vertical cracks occur; this protective role means that many of the older, upper passages of the cave system are dry, with no stalactites, stalagmites, or other formations which require flowing or dripping water to develop. However, the sandstone caprock layer has been dissolved and eroded at many locations within the park, such as the Frozen Niagara room; the contact between limestone and sandstone can be found by hiking from the valley bottoms to the ridgetops: as one approaches the top of a ridge, one sees the outcrops of exposed rock change in composition from limestone to sandstone at a well-defined elevation.
At one valley bottom in the southern region of the park, a massive sinkhole has developed. Known as Cedar Sink, the sinkhole features a small river entering one side and disappearing back underground at the other side. Mammoth Cave is home to a sightless albino shrimp; the National Park Service offers several cave tours to visitors. Some notable features of the cave, such as Grand Avenue, Frozen Niagara, Fat Man's Misery, can be seen on lighted tours ranging from one to six hours in length. Two tours, lit only by visitor-carried paraffin lamps, are popular alternatives to the electric-lit routes. Several "wild" tours venture away from the developed parts of the cave into muddy crawls and dusty tunnels; the Echo River Tour, one of the cave's most famous attractions, used to take visitors on a boat ride along an underground river. The tour was discontinued for environmental reasons in the early 1990s. Mammoth Cave headquarters and visitor's center is located on Mammoth Cave Parkway; the parkway connects with Kentucky Route 70 from the north and Kentucky Route 255 from the south within the park.
The story of human beings in relation to Mammoth Cave spans six thousand years. Several sets of Native American remains have been recovered from Mammoth Cave, or other nearby caves in the region, in both the 19th and 20th centuries. Most mummies found represent examples of intentional burial, with ample evidence of pre-Columbian funerary practice. An exception to purposeful burial was discovered when in 1935 the remains of an adult male were discovered under a large boulder; the boulder had shifted and settled onto the victim, a pre-Columbian miner, who had disturbed the rubble supporting it. The remains of the ancient victim were named "Lost John" and exhibited to the public into the 1970s, when they were interred in a secret location in Mammoth Cave for reasons of preservation as well as emerging political sensitivities with respect to the public display of Native American remains. Research beginning in the late 1950s led by Patty Jo Watson, of Washington University in St. Louis, has done much to illuminate the lives of the late Archaic and early Woodland peoples who explored and exploited caves in the region.
Preserved by the constant cave environment, dietary evidence yielded carbon dates enabling Watson and others to determine the age of t
Bear Butte
Bear Butte is a geological laccolith feature located near Sturgis, South Dakota, United States, established as a State Park in 1961. An important landmark and religious site for the Plains Indians tribes long before Europeans reached South Dakota, Bear Butte is called Matȟó Pahá, or Bear Mountain, by the Lakota, or Sioux. To the Cheyenne, it is known as Noahȧ-vose or Náhkȯhe-vose, is the place where Ma'heo'o imparted to Sweet Medicine, a Cheyenne prophet, the knowledge from which the Cheyenne derive their religious, political and economic customs; the mountain is sacred to many indigenous peoples, who make pilgrimages to leave prayer cloths and tobacco bundles tied to the branches of the trees along the mountain's flanks. Other offerings are left at the top of the mountain; the site is associated with various religious ceremonies throughout the year. The mountain is a place of prayer and peace; the park includes a campsite west of South Dakota Highway 79 where horseback riding and boating are permitted.
On the summit side of Highway 79, a moderately sized herd of buffalo roams the base of the mountain. An education center and a summit trail are available. Official park policy advises visitors to Bear Butte to respect worshipers and to leave religious offerings undisturbed. Park fees are waived for those undertaking religious activities. In 2007, Gov. Mike Rounds of South Dakota announced a proposal to use state and private money to buy a perpetual easement in order to prevent commercial and residential development of some land on the western side of Bear Butte; this would cost more than $1 million, but would prevent development of nuisance businesses on ranch land near the mountain on the northern edge of the Black Hills. Bear Butte is not a butte, but a laccolith: an intrusive body of igneous rock, uplifting the earlier sedimentary layers, which have since eroded away; this is the result of the forcible entry of magma into cooler crustal rock in the Black Hills area during the Eocene Epoch.
In this, Bear Butte shares a similar geological history with other formations in the region, including the Black Hills, Devils Tower, the Missouri Buttes, some parts of the Rocky Mountains. It is possible that when the intrusion was emplaced, some magma may have breached the surface, forming a volcano; the peak is 4,426 feet above sea level. Human artifacts have been found on or near Bear Butte that date back 10,000 years, indicating a long and continuous interest in the mountain; the Cheyenne and Lakota people have maintained a spiritual interest in Bear Butte from their earliest recorded history. Notable visitors like Red Cloud, Crazy Horse, Sitting Bull made pilgrimages to the site. In 1857, a council of many Indian nations gathered at Bear Butte to discuss the growing presence of white settlers in the Black Hills. Violating a treaty of 1868, George Armstrong Custer led an expedition to the Black Hills region in 1874, according to custom he camped near Bear Butte. Custer verified the rumors of gold in the Black Hills, Bear Butte served as an identifiable landmark for the rush of invading prospectors and settlers into the region.
Indian reaction to the illegal movements of whites into the area was hostile. The government reneged on its treaty obligations regarding the Black Hills and instead embarked on a program to confine all northern Plains tribes to reservations. Ezra Bovee homesteaded on the southern slopes of the mountain, by the time of World War II, he and his family were the legal owners of the site. In the spring of 1945, the Northern Cheyenne received permission from Bovee to hold a ceremony at Bear Butte to pray for the end of World War II; the Cheyenne found that the Bovee family welcomed their interest in the mountain, over the years the Bovees continued to encourage native religious ceremonies. By the mid-1950s Ezra Bovee was attempting to stir up interest in making Bear Butte a national park. After his death, his family continued the effort; when federal interest in the project waned, the state government in Pierre took action, Bear Butte became a state park in 1961 and was registered as a National Historic Landmark in 1981.
Frank Fools Crow, the Lakota ceremonial chief, made pilgrimages to Bear Butte throughout his lifetime. Fools Crow taught racial harmony not just between whites and Indians, but among all the peoples of the world, he believed. A bust and plaque in front of the education center at Bear Butte State Park honor Fools Crow's efforts. Frank Fools Crow was the plaintiff in one of the most prominent attempts by Native Americans to gain access to sacred lands under the American Indian Religious Freedom Act of 1978; the case, Fools Crow v. Gullett, related to the introduction in 1982 of limits on when and for how long Lakota and Cheyenne religious ceremonies could take place on the Bluff; the Indian Americans argued that both the American Indian Religious Freedom Act and the First Amendment protected their right to unlimited access to the Bluff. They wanted the Bluff to remain untouched as it was sacred; the plaintiffs lost their case on both the District and Appellate level and were denied a hearing by the Supreme Court.
In 2011, the National Trust for Historic Preservation included Bear Butte on its list of the 11 Most Endangered Places. List of National Historic Landmarks in South Dakota National Register of Historic Places listings in Meade County, South Dakota List of South Dakota state parks Oehlerking, Jerry. T
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