U.S. National Geodetic Survey
"United States Coast Survey" and "United States Coast and Geodetic Survey" redirect here. They are former scientific agencies of the United States government which should not be confused with the United States Coast Guard, a seagoing U. S. government law enforcement and safety agency, the modern Coast Survey, a U. S. government agency that makes nautical charts, or the United States Geological Survey, a U. S. government agency that studies earth science and makes topographical maps. The National Geodetic Survey the United States Survey of the Coast, United States Coast Survey, United States Coast and Geodetic Survey, is a United States federal agency that defines and manages a national coordinate system, providing the foundation for transportation and communication. Since its foundation in its present form in 1970, it has been part of the National Oceanic and Atmospheric Administration, of the United States Department of Commerce; the National Geodetic Survey's history and heritage are intertwined with those of other NOAA offices.
As the U. S. Coast Survey and U. S. Coast and Geodetic Survey, the agency operated a fleet of survey ships, from 1917 the Coast and Geodetic Survey was one of the uniformed services of the United States with its own corps of commissioned officers. Upon the creation of the Environmental Science Services Administration in 1965, the commissioned corps was separated from the Survey to become the Environmental Science Services Administration Corps. Upon the creation of NOAA in 1970, the ESSA Corps became the National Oceanic and Atmospheric Administration Commissioned Officer Corps. Thus, the National Geodetic Survey's ancestor organizations are the ancestors of today's NOAA Corps and Office of Coast Survey and are among the ancestors of today's NOAA fleet. In addition, today's National Institute of Standards and Technology, although long since separated from the Survey, got its start as the Survey's Office of Weights and Measures; the National Geodetic Survey is an office of NOAA's National Ocean Service.
Its core function is to maintain the National Spatial Reference System, "a consistent coordinate system that defines latitude, height, scale and orientation throughout the United States." NGS is responsible for defining the NSRS and its relationship with the International Terrestrial Reference Frame. The NSRS enables precise and accessible knowledge of where things are in the United States and its territories; the NSRS may be divided into its geometric and physical components. The official geodetic datum of the United States, NAD83 defines the geometric relationship between points within the United States in three-dimensional space; the datum may be accessed via NGS's network of survey marks or through the Continuously Operating Reference Station network of GPS reference antennas. NGS is responsible for computing the relationship between NAD83 and the ITRF; the physical components of the NSRS are reflected in its height system, defined by the vertical datum NAVD88. This datum is a network of orthometric heights obtained through spirit leveling.
Because of the close relationship between height and Earth's gravity field, NGS collects and curates terrestrial gravity measurements and develops regional models of the geoid and its slope, the deflection of the vertical. NGS is responsible for ensuring the accuracy of the NSRS over time as the North American plate rotates and deforms over time due to crustal strain, post-glacial rebound, elastic deformation of the crust, other geophysical phenomena. NGS will release new datums in 2022; the North American Terrestrial Reference Frame of 2022 will supersede NAD83 in defining the geometric relationship between the North American plate and the ITRF. United States territories on the Pacific and Mariana plates will have their own respective geodetic datums; the North American-Pacific Geopotential Datum of 2022 will separately define the height system of the United States and its territories, replacing NAVD88. It will use a geoid model accurate to 1 centimeter to relate orthometric height to ellipsoidal height measured by GPS, eliminating the need for future leveling projects.
This geoid model will be based on airborne and terrestrial gravity measurements collected by NGS's GRAV-D program as well as satellite-based gravity models derived from observations collected by GRACE, GOCE, satellite altimetry missions. NGS provides a number of other public services, it maps changing shorelines in the United States and provides aerial imagery of regions affected by natural disasters, enabling rapid damage assessment by emergency managers and members of the public. The Online Positioning and User Service processes user-input GPS data and outputs position solutions within the NSRS; the agency offers other tools for conversion between datums. The original predecessor agency of the National Geodetic Survey was the United States Survey of the Coast, created within the United States Department of the Treasury by an Act of Congress on February 10, 1807, to conduct a "Survey of the Coast." The Survey of the Coast, the United States government's first scientific agency, represented the interest of the administration of President Thomas Jefferson in science and the stimulation of international trade by using scientific surveying methods to chart t
In topography, prominence measures the height of a mountain or hill's summit relative to the lowest contour line encircling it but containing no higher summit within it. It is a measure of the independence of a summit. A peak's key col is a unique point on this contour line and the parent peak is some higher mountain, selected according to various objective criteria. There are at least two definitions of prominence: The prominence of a peak is the minimum height necessary to descend to get from the summit to any higher terrain, which can be calculated for a given peak in the following way: for every path connecting the peak to higher terrain, find the lowest point on the path. See Figure 1; the prominence of a peak is the height of the peak’s summit above the lowest contour line encircling it but containing no higher summit within it. This allows the prominence of points like Everest to be calculated, as long as a lowest point can be defined; the following mental exercise may illustrate the meaning of topographic prominence.
Imagine a peak and imagine that an imaginary sea level rises to the peak. Now lower the imaginary sea level and an imaginary island appears beneath your feet; the island will merge with other islands that emerge. The island will touch an island with a higher peak than the initial island The summit of that island is the parent peak of the summit, the point at which the two islands touch is the key col of the summit, the elevation rise from the key col to the summit is the topographic prominence of the summit; the parent peak may be either far from the subject peak. The summit of Mount Everest is the parent peak of Aconcagua at a distance of 17,755 km, as well as the parent of the South Summit of Mount Everest at a distance of 360 m; the key col may be close to the subject peak or far from it. The key col for Aconcagua, if sea level is disregarded, is the Bering Strait at a distance of 13,655 km; the key col for the South Summit of Mount Everest is about 100 m distant. Prominence is interesting to many mountaineers because it is an objective measurement, correlated with the subjective significance of a summit.
Peaks with low prominence are either subsidiary tops of some higher summit or insignificant independent summits. Peaks with high prominence tend to be the highest points around and are to have extraordinary views. Only summits with a sufficient degree of prominence are regarded as independent mountains. For example, the world's second-highest mountain is K2. While Mount Everest's South Summit is taller than K2, it is not considered an independent mountain because it is a sub-summit of the main summit. Many lists of mountains take topographic prominence as cutoff. John and Anne Nuttall's The Mountains of England and Wales uses a cutoff of 15 m, Alan Dawson's list of Marilyns uses 150 m.. In the contiguous United States, the famous list of "fourteeners" uses a cutoff of 300 ft / 91 m. In the U. S. 2000 ft of prominence has become an informal threshold that signifies that a peak has major stature. Lists with a high topographic prominence cutoff tend to favor isolated peaks or those that are the highest point of their massif.
While the use of prominence as a cutoff to form a list of peaks ranked by elevation is standard and is the most common use of the concept, it is possible to use prominence as a mountain measure in itself. This generates lists of peaks ranked by prominence, which are qualitatively different from lists ranked by elevation; such lists tend to emphasize isolated high peaks, such as range or island high points and stratovolcanoes. One advantage of a prominence-ranked list is that it needs no cutoff since a peak with high prominence is automatically an independent peak, it is common to define a peak's parent as a particular peak in the higher terrain connected to the peak by the key col. If there are many higher peaks there are various ways of defining which one is the parent, not based on geological or geomorphological factors; the "parent" relationship defines a hierarchy. For example, in Figure 1, the middle peak is a subpeak of the right peak, in turn a subpeak of the left peak, the highest point on its landmass.
In that example, there is no controversy over the hierarchy. These different definitions follow. A special case occurs for the highest point on an oceanic continent; some sources define no parent in this case. Called prominence island parentage, this is defined as follows. In figure 2 the key col of peak A is at the meeting place of two closed contours, one encircling A and the other containing at least one higher peak; the encirclement parent of A is the highest peak, inside this other contour. In terms of the
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
Ivanpah Lake is a dry lake bed in the Mojave Desert of San Bernardino County, California on the border of California and Nevada. Nestled in the Ivanpah Valley near Primm on Interstate 15, the 13-square-mile lake is entirely within California. At the north edge of the lake lie a California Lottery retailer, it is a popular place for land kite buggying. On March 26, 2009, the world land speed record for a wind-powered vehicle was set here by the Greenbird, clocked at 126.1 mph. Hundreds of thousands of gallons of water carrying radioactive waste from rare earth element mining spilled into and around Ivanpah Dry Lake. In the 1980s, the Mountain Pass rare earth mine began piping wastewater as far as 14 miles to evaporation ponds on or near Ivanpah Dry Lake, east of Interstate 15 near Nevada; this pipeline ruptured during cleaning operations to remove mineral deposits called scale. The scale is radioactive because of the presence of thorium and radium, which occur in the rare earth ore. A federal investigation found that some 60 spills—some unreported—occurred between 1984 and 1998, when the pipeline was shut down.
In all, about 600,000 US gallons of radiological and other hazardous waste flowed onto the desert floor, according to federal authorities. By the end of the 1990s, Unocal had been hit with a cleanup order and a San Bernardino County district attorney's lawsuit; the company paid more than $1.4 million in settlements. After preparing a cleanup plan and completing an extensive environmental study, Unocal in 2004 won approval of a county permit that allowed the mine to operate for another 30 years. In 2008, Unocal/Chevron sold the mine to held Molycorp Minerals LLC, a company formed to revive the Mountain Pass Mine. List of lakes in California U. S. Geological Survey Geographic Names Information System: Ivanpah Lake Satellite Photo Bureau of Land Management - Needles CA district including access information
Abies concolor, the white fir, is a coniferous tree in the pine family Pinaceae. This tree is native to the mountains of western North America from the southern Cascade range in Oregon, south throughout California and into the Sierra de San Pedro Mártir in northern Baja California. White fir live over 300-years and occur at an elevation between 900–3,400 m, it is popular as a Christmas tree. The specific epithet concolor means "all one color"; this large evergreen coniferous tree grows best in the central Sierra Nevada of California, where the record specimen was recorded as 74.9 m tall and measured 4.6 m in diameter at breast height in Yosemite National Park. The typical size of white fir ranges from 25–60 m tall and up to 2.7 m dbh. The largest specimens are found in the central Sierra Nevada, where the largest diameter recorded was found in Sierra National Forest at 58.5 x 8.5 m Rocky mountain white fir exceed 38 m tall or 0.9 m dbh. Large but not huge trees, in good soil, range from 40 to 60 m tall and from 99 to 165 cm dbh in California and southwestern Oregon and to 41 m tall and 124 cm dbh in Arizona and New Mexico.
The leaves are needle-like, flattened, 2.5–6 cm long and 2 mm wide by 0.5–1 mm thick, green to glaucous blue-green above, with two glaucous blue-white bands of stomatal bloom below, notched to bluntly pointed at the tip. The leaf arrangement is spiral on the shoot, but with each leaf variably twisted at the base so they all lie in either two more-or-less flat ranks on either side of the shoot, or upswept across the top of the shoot but not below the shoot; the cones are 6–12 cm long and 4–4.5 cm broad, green or purple ripening pale brown, with about 100–150 scales. The winged seeds are released when the cones disintegrate at maturity about 6 months after pollination; as treated here, there are two subspecies. Concolor — Colorado white fir or Rocky Mountains white fir. In the United States, at altitudes of 1,700–3,400 m in the Rocky Mountains from southern Idaho, south through Utah and Colorado, to New Mexico and Arizona, on the higher Great Basin mountains of Nevada and extreme southeastern California, a short distance into northern Sonora, Mexico.
A smaller tree to 25–35 m tall 45 m. Foliage upcurved to erect on all except weak shaded shoots in the lower crown. Tolerates winter temperatures down to about −40 °C. Abies concolor subsp. Lowiana — Low's white fir or Sierra Nevada white fir. In the United States, at altitudes of 900–2,300 m from the Cascades of central Oregon south through California to northern Baja California, Mexico. A larger tree to 40–60 m tall. Foliage flattened on lower crown shoots, the leaves raised above the shoot on upper crown shoots but not strongly upcurved. Tolerates winter temperatures down to about −30 °C; the United States Department of Agriculture plants database describes this subspecies as the full species Sierra white fir - Abies lowiana A. Murray bis. White fir is closely related to grand fir, with subspecies lowiana being similar to the interior variety of grand fir A. grandis var. idahoensis, intergrading with it where they meet in the Cascades of central Oregon. To the south in Mexico, it is replaced by Durango fir and Mexican fir.
White fir is a shade tolerant, climax species, which means the forest has reached complex maturity in forest succession in western coniferous forests of the United States. White fir and yellow pine have co-existed for millennia in old growth forests throughout their range. In the presence of logging of large diameter trees and exclusion of cleansing wildfires, young trees have become abundant over the past two centuries. White fir had been regarded as a pest in the past by those in the lumber industry, but this opinion has changed. White fir is now one of the most important of all commercial softwoods according to the Western Wood Products Association; the white fir trait of retaining lower limbs creates an escape route for medium to small forest birds from larger flying predators and provides a drip zone around the roots for collecting moisture. The retained limbs can become a fire ladder. Limbing-up white fir, instead of removing medium to large diameter trees, in areas where the public is more to start fires can help keep other trees and giant sequoia from experiencing canopy fire.
Recent concern for sequoia groves has caused agencies to call for removal of white fir in the Sierra Nevada. While sequoia seedlings and young saplings are susceptible to mortality or serious injury by fire.
Rock climbing is a sport in which participants climb up, down or across natural rock formations or artificial rock walls. The goal is to reach the summit of a formation or the endpoint of a pre-defined route without falling. Professional rock climbing competitions have the objectives of either completing the route in the quickest possible time or attaining the farthest point on an difficult route. Due to the length of time and extended endurance required, because accidents are most to happen on the descent, rock climbers do not climb back down the route, or "downclimb" on the larger multiple pitch class III–IV, or multi-day grade IV–VI climbs. Rock climbing is a physically and mentally demanding sport, one that tests a climber's strength, endurance and balance along with mental control, it can be a dangerous activity and knowledge of proper climbing techniques and use of specialized climbing equipment is crucial for the safe completion of routes. Because of the wide range and variety of rock formations around the world, rock climbing has been separated into several different styles and sub-disciplines, such as scrambling, another activity involving the scaling of hills and similar formations, differentiated by rock climbing's sustained use of hands to support the climber's weight as well as to provide balance.
Paintings dating from 200 BC show Chinese men rock climbing. In early America, the cliff-dwelling Anasazi in the 12th century are thought to have been excellent climbers. Early European climbers used rock climbing techniques as a skill required to reach the summit in their mountaineering exploits. In the 1880s, European rock climbing became an independent pursuit outside of mountain climbing. Although rock climbing was an important component of Victorian mountaineering in the Alps, it is thought that the sport of rock climbing began in the last quarter of the nineteenth century in various parts of Europe. Rock climbing evolved from an alpine necessity to a distinct athletic activity. Aid climbing, climbing using equipment that acts as artificial handhold or footholds, became popular during the period 1920–1960, leading to ascents in the Alps and in Yosemite Valley that were considered impossible without such means. However, climbing techniques and ethical considerations have evolved steadily.
Today, free climbing, climbing using holds made of natural rock while using gear for protection and not for upward movement, is the most popular form of the sport. Free climbing has since been divided into several sub-styles of climbing dependent on belay configuration. Over time, grading systems have been created in order to compare more the relative difficulties of the rock climbs. In How to Rock Climb, John Long notes that for moderately skilled climbers getting to the top of a route is not enough. Within free climbing, there are distinctions given to ascents: on-sight and redpoint. To on-sight a route is to ascend the wall without aid or any foreknowledge, it is considered the way to climb with the most style. Flashing is similar to on-sighting, except that the climber has previous information about the route including talking about the beta with other climbers. Redpointing means to make a free ascent of the route after having first tried it. Style is up to each individual climber and among climbers the verbiage and definitions can differ.
Most of the climbing done in modern times is considered free climbing—climbing using one's own physical strength, with equipment used as protection and not as support—as opposed to aid climbing, the gear-dependent form of climbing, dominant in the sport's earlier days. Free climbing is divided into several styles that differ from one another depending on the choice of equipment used and the configurations of their belay and anchor systems; as routes get higher off the ground, the increased risk of life-threatening injuries necessitates additional safety measures. A variety of specialized climbing techniques and climbing equipment exists to provide that safety. Climbers will work in pairs and utilize a system of ropes and anchors designed to catch falls. Ropes and anchors can be configured in different ways to suit many styles of climbing, roped climbing are thus divided into further sub-types that vary based on how their belay systems are set up. Speaking, beginners will start with top roping and/or easy bouldering and work their way up to lead climbing and beyond.
Still the most popular method of climbing big walls, aid climbers make progress up a wall by placing and weighting gear, used directly to aid ascent and enhance safety. This form of climbing is used when ascent is too technically difficult or impossible for free climbing; the most used method to ascend climbs refers to climbs where the climber's own physical strength and skill are relied on to accomplish the climb. Free climbing may rely on top rope belay systems, or on lead climbing to establish protection and the belay stations. Anchors and protection are used to back up the climber and are passive as opposed to active ascending aids. Subtypes of free climbing are trad sport climbing. Free climbing is done as "clean lead" meaning no pitons or pins are used as protection. Climbing on short, low routes without the use of the safety rope, typical of most other styles. Protection, if used at all consists of a cushioned bouldering pad below the route and a spotter, a person who watches from below and directs the fall of the climber away from hazardous areas.
Bouldering may be an arena for intense and safe competition, resulting in exceptionally high diffic