The President and Fellows of the Royal Society of London for Improving Natural Knowledge known as the Royal Society, is a learned society. Founded on 28 November 1660, it was granted a royal charter by King Charles II as "The Royal Society", it is the oldest national scientific institution in the world. The society is the United Kingdom's and Commonwealth of Nations' Academy of Sciences and fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, fostering international and global co-operation and public engagement; the society is governed by its Council, chaired by the Society's President, according to a set of statutes and standing orders. The members of Council and the President are elected from and by its Fellows, the basic members of the society, who are themselves elected by existing Fellows; as of 2016, there are about 1,600 fellows, allowed to use the postnominal title FRS, with up to 52 new fellows appointed each year.
There are royal fellows, honorary fellows and foreign members, the last of which are allowed to use the postnominal title ForMemRS. The Royal Society President is Venkatraman Ramakrishnan, who took up the post on 30 November 2015. Since 1967, the society has been based at 6–9 Carlton House Terrace, a Grade I listed building in central London, used by the Embassy of Germany, London; the Invisible College has been described as a precursor group to the Royal Society of London, consisting of a number of natural philosophers around Robert Boyle. The concept of "invisible college" is mentioned in German Rosicrucian pamphlets in the early 17th century. Ben Jonson in England referenced the idea, related in meaning to Francis Bacon's House of Solomon, in a masque The Fortunate Isles and Their Union from 1624/5; the term accrued currency for the exchanges of correspondence within the Republic of Letters. In letters in 1646 and 1647, Boyle refers to "our invisible college" or "our philosophical college".
The society's common theme was to acquire knowledge through experimental investigation. Three dated letters are the basic documentary evidence: Boyle sent them to Isaac Marcombes, Francis Tallents who at that point was a fellow of Magdalene College and London-based Samuel Hartlib; the Royal Society started from groups of physicians and natural philosophers, meeting at a variety of locations, including Gresham College in London. They were influenced by the "new science", as promoted by Francis Bacon in his New Atlantis, from 1645 onwards. A group known as "The Philosophical Society of Oxford" was run under a set of rules still retained by the Bodleian Library. After the English Restoration, there were regular meetings at Gresham College, it is held that these groups were the inspiration for the foundation of the Royal Society. Another view of the founding, held at the time, was that it was due to the influence of French scientists and the Montmor Academy in 1657, reports of which were sent back to England by English scientists attending.
This view was held by Jean-Baptiste du Hamel, Giovanni Domenico Cassini, Bernard le Bovier de Fontenelle and Melchisédech Thévenot at the time and has some grounding in that Henry Oldenburg, the society's first secretary, had attended the Montmor Academy meeting. Robert Hooke, disputed this, writing that: makes Mr Oldenburg to have been the instrument, who inspired the English with a desire to imitate the French, in having Philosophical Clubs, or Meetings. I will not say, that Mr Oldenburg did rather inspire the French to follow the English, or, at least, did help them, hinder us. But'tis well known who were the principal men that began and promoted that design, both in this city and in Oxford, and not only these Philosophic Meetings were. On 28 November 1660, the 1660 committee of 12 announced the formation of a "College for the Promoting of Physico-Mathematical Experimental Learning", which would meet weekly to discuss science and run experiments. At the second meeting, Sir Robert Moray announced that the King approved of the gatherings, a royal charter was signed on 15 July 1662 which created the "Royal Society of London", with Lord Brouncker serving as the first president.
A second royal charter was signed on 23 April 1663, with the king noted as the founder and with the name of "the Royal Society of London for the Improvement of Natural Knowledge". This initial royal favour has continued and, since every monarch has been the patron of the society; the society's early meetings included experiments performed first by Hooke and by Denis Papin, appointed in 1684. These experiments varied in their subject area, were both important in some cases and trivial in others; the society published an English translation of Essays of Natural Experiments Made in the Accademia del Cimento, under the Protection of the Most Serene Prince Leopold of Tuscany in 1684, an Italian book documenting experiments at the Accademia del Cimento. Although meeting at Gresham College, the Society temporarily moved to Arundel House in 1666 after the Great Fire of London, which did not harm Gresham but did lead to its appropriation by the Lord Mayor; the Society r
National Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration is an American scientific agency within the United States Department of Commerce that focuses on the conditions of the oceans, major waterways, the atmosphere. NOAA warns of dangerous weather, charts seas, guides the use and protection of ocean and coastal resources, conducts research to provide understanding and improve stewardship of the environment. NOAA was formed in 1970 and in 2017 had over 11,000 civilian employees, its research and operations are further supported by 321 uniformed service members who make up the NOAA Commissioned Corps. Since October 2017, NOAA has been headed by Timothy Gallaudet, as acting Under Secretary of Commerce for Oceans and Atmosphere and NOAA interim administrator. NOAA plays several specific roles in society, the benefits of which extend beyond the US economy and into the larger global community: A Supplier of Environmental Information Products. NOAA supplies to its customers and partners information pertaining to the state of the oceans and the atmosphere.
This is clear through the production of weather warnings and forecasts via the National Weather Service, but NOAA's information products extend to climate and commerce as well. A Provider of Environmental Stewardship Services. NOAA is a steward of U. S. coastal and marine environments. In coordination with federal, local and international authorities, NOAA manages the use of these environments, regulating fisheries and marine sanctuaries as well as protecting threatened and endangered marine species. A Leader in Applied Scientific Research. NOAA is intended to be a source of accurate and objective scientific information in the four particular areas of national and global importance identified above: ecosystems, climate and water, commerce and transportation; the five "fundamental activities" are: Monitoring and observing Earth systems with instruments and data collection networks. Understanding and describing Earth systems through research and analysis of that data. Assessing and predicting the changes of these systems over time.
Engaging and informing the public and partner organizations with important information. Managing resources for the betterment of society and environment. NOAA traces its history back to multiple agencies, some of which were among the oldest in the federal government: United States Coast and Geodetic Survey, formed in 1807 Weather Bureau of the United States, formed in 1870 Bureau of Commercial Fisheries, formed in 1871 Coast and Geodetic Survey Corps, formed in 1917Another direct predecessor of NOAA was the Environmental Science Services Administration, into which several existing scientific agencies such as the United States Coast and Geodetic Survey, the Weather Bureau and the uniformed Corps were absorbed in 1965. NOAA was established within the Department of Commerce via the Reorganization Plan No. 4 and formed on October 3, 1970 after U. S. President Richard Nixon proposed creating a new agency to serve a national need for "better protection of life and property from natural hazards …for a better understanding of the total environment… for exploration and development leading to the intelligent use of our marine resources."
In 2007, NOAA celebrated 200 years of service in its role as successor to the United States Survey of the Coast. In 2013, NOAA closed 600 weather stations. Since October 25, 2017 Timothy Gallaudet, Assistant Secretary of Commerce for Oceans and Atmosphere, has served as acting Under Secretary of Commerce for Oceans and Atmosphere at the US Department of Commerce and NOAA's interim administrator. Gallaudet succeeded Benjamin Friedman, who served as NOAA's interim administrator since the end of the Obama Administration on January 20, 2017. In October 2017, Barry Lee Myers, CEO of AccuWeather, was proposed to be the agency's administrator by the Trump Administration. NOAA works toward its mission through six major line offices, the National Environmental Satellite and Information Service, the National Marine Fisheries Service, the National Ocean Service, the National Weather Service, the Office of Oceanic and Atmospheric Research and the Office of Marine & Aviation Operations, and in addition more than a dozen staff offices, including the Office of the Federal Coordinator for Meteorology, the NOAA Central Library, the Office of Program Planning and Integration.
The National Weather Service is tasked with providing "weather and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy." This is done through a collection of national and regional centers, 13 river forecast centers, more than 120 local weather forecast offices. They are charged with issuing weather and river forecasts, advisories and warnings on a daily basis, they issue more than 734,000 weather and 850,000 river forecasts, more than 45,000 severe weather warnings annually. NOAA data is relevant to the issues of global warming and ozone depletion; the NWS operates NEXRAD, a nationwide network of Doppler weather radars which can detect precipitation and their velocities. Many of their products are broadcast on NOAA Weather Radio, a network of radio transmitters that broadcasts weather forecasts, severe weather statements and warnings 24 hours a day; the National Ocean Service focuses on ensuring that ocean and coastal areas are safe and productive.
NOS scientists, natural resource managers, specialists serve America by ensuring safe and efficient marine transportation, promoting innovative solutions to protect coastal communities, conserving mari
The Challenger Deep is the deepest known point in the Earth's seabed hydrosphere, with a depth of 10,898 to 10,916 m by direct measurement from submersibles and more by sonar bathymetry. It is located in the Pacific Ocean, at the southern end of the Mariana Trench near the Mariana Islands group; the Challenger Deep is a small slot-shaped depression in the bottom of a larger crescent-shaped oceanic trench, which itself is an unusually deep feature in the ocean floor. The Challenger Deep's bottom is about 11 km long and 1.6 km wide, with sloping sides. The closest land to the Challenger Deep is Fais Island, 287 km southwest, Guam, 304 km to the northeast, it is located in the ocean territory of the Federated States of Micronesia, 1.6 km from its border with ocean territory associated with Guam. The depression is named after the British Royal Navy survey ship HMS Challenger, whose expedition of 1872–1876 made the first recordings of its depth. According to the August 2011 version of the GEBCO Gazetteer of Undersea Feature Names, the location and depth of the Challenger Deep are 11°22.4′N 142°35.5′E and 10,920 m ±10 m.
A 2014 study by Gardner et al. concludes that with the best of 2010 multibeam echosounder technologies a depth uncertainty of ±25 m on nine degrees of freedom and a positional uncertainty of ±20 to 25 m remains. The deepest point and its location recorded in the 2010 sonar mapping conducted by the US Center for Coastal & Ocean Mapping/Joint Hydrographic Center aboard USNS Sumner is 10,984 m at 11.329903°N 142.199305°E / 11.329903. In November 2016 sonar mapping of the Challenger Deep area was conducted by the Royal Netherlands Institute for Sea Research /GEOMAR Helmholtz Centre for Ocean Research Kiel aboard RV Sonne. Using a Kongsberg Maritime EM 122 multibeam echosounder system coupled to positioning equipment that can determine latitude and longitude the team determined that the Challenger Deep has a maximum depth of 10,925 m at 11.332417°N 142.20205°E / 11.332417. The horizontal position of the grid point has an uncertainty of ±50 to 100 m, depending on along-track or across-track direction.
This depth and position measurements differ from the deepest point determined by the Gardner et al. study. The high water pressure at this depth makes operating exploratory craft difficult. Only four descents have been achieved; the first descent by any vehicle was by the manned bathyscaphe Trieste in 1960. This was followed by the unmanned ROVs Kaikō in 1995 and Nereus in 2009. In March 2012 a manned solo descent was made by film director James Cameron in the deep-submergence vehicle Deepsea Challenger. Over many years, the search for the point of maximum depth has involved many different vessels; the Challenger expedition first sounded the depths now known as the Challenger Deep. This first sounding was made on 23 March 1875 at station 225; the reported depth was 4,475 fathoms at 11°24′N 143°16′E, based on two separate soundings. A 1912 book, The Depths of the Ocean by Sir John Murray, records the depth of the Challenger Deep as 31,614 ft, reporting the sounding taken by the converted navy collier USS Nero in 1899.
Murray was one of the expedition scientists. In 1951, about 75 years after its original discovery, the entire Mariana Trench was surveyed by a second Royal Navy vessel, captained by George Stephen Ritchie; this survey recorded the deepest part of the trench using echo sounding, a more precise and easier way to measure depth than the sounding equipment and drag lines used in the original expedition. A depth of 5,960 fathoms was measured at 11°19′N 142°15′E; the maximum surveyed depth of the Challenger Deep was reported in 1957 by the Soviet Research vessel Vityaz recording a spot 11,034 metres ±50 m deep at 11°20.9′N 142°11.5′E. It was dubbed the Mariana Hollow and is listed in many reference sources, including the Encyclopædia Britannica, articles in National Geographic and on maps; the pressure at this depth is 1,099 times atmospheric pressure, or 111 MPa. In 1959, the US Navy research vessel RV Stranger using bomb-sounding surveyed a maximum depth of 10,915 m ±10 m at 11°20.0′N 142°11.8′E. In 1962, the US Navy research vessel RV Spencer F. Baird using a frequency-controlled depth recorder surveyed a maximum depth of 10,915 m ±10 m at 11°20.0′N 142°11.8′E.
In 1975 and 1980, the US Navy research vessel RV Thomas Washington using a precision depth recorder with satellite positioning surveyed a maximum depth of 10,915 m ±10 m at 11°20.0′N 142°11.8′E. In 1984, the survey vessel Takuyo from the Hydrographic Department of Japan, used a narrow, multibeam echo sounder to take a measurement of 10,924 m ±10 m at 11°22.4′N 142°35.5′E. In 1998, a regional bathymetric survey of the Challenger Deep was conducted by the Deep Sea Research Vessel RV Kairei, from the Japan Agency for Marine-Earth Science and Technology, using a SeaBeam 2112 multibeam echosounder; the regional bathymetric map made from the data obtained in 1998 shows that the greatest depths in the eastern and western depressions are 10,922 m ±74 m, 10,898 m
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net, used for trawling is called a trawl; the boats that are used for trawling are called draggers. Trawlers vary in size from small open boats with as little as 30 hp engines to large factory trawlers with over 10,000 hp. Trawling can be carried out by two trawlers fishing cooperatively. Trawling can be contrasted with trolling, where baited fishing lines instead of trawls are drawn through the water. Trolling is used both for recreational and commercial fishing whereas trawling is used for commercial fishing. Trawling is commonly used as a scientific sampling, or survey, method. Trawling can be divided into bottom trawling and midwater trawling, depending on how high the trawl is in the water column. Bottom trawling is towing the trawl close to the sea floor. Midwater trawling is towing the trawl through free water above the bottom of the ocean or benthic zone. Midwater trawling is known as pelagic trawling.
Midwater trawling catches pelagic fish such as anchovies, shrimp and mackerel, whereas bottom trawling targets both bottom-living fish and semi-pelagic fish such as cod and rockfish. The gear itself can vary a great deal. Pelagic trawls are much larger than bottom trawls, with large mesh openings in the net, little or no ground gear, little or no chaffing gear. Additionally, pelagic trawl doors have different shapes than bottom trawl doors, although doors that can be used with both nets do exist; when two boats are used, the horizontal spread of the net is provided by the boats, with one or in the case of pelagic trawling two warps attached to each boat. However, single-boat trawling is more common. Here, the horizontal spread of the net is provided by trawl doors. Trawl doors are available in various sizes and shapes and may be specialized to keep in contact with the sea bottom or to remain elevated in the water. In all cases, doors act as wings, using a hydrodynamic shape to provide horizontal spread.
As with all wings, the towing vessel must go at a certain speed for the doors to remain standing and functional. This speed varies, but is in the range of 2.5–4.0 knots. The vertical opening of a trawl net is created using flotation on the upper edge and weight on the lower edge of the net mouth; the configuration of the footrope varies based on the expected bottom shape. The more uneven the bottom, the more robust the footrope configuration must be to prevent net damage; this is used to catch shrimp, cod and many others. Trawls are funnel-shaped nets that have a closed-off tail where the fish are collected and is open on the top end as the mouth. Trawl nets can be modified, such as changing mesh size, to help with marine research of ocean bottoms. Although trawling today is regulated in some nations, it remains the target of many protests by environmentalists. Environmental concerns related to trawling refer to two areas: the lack of selectivity and the physical damage which the trawl does to the seabed.
Since the practice of trawling started, there have been concerns over trawling's lack of selectivity. Trawls may be non-selective, sweeping both marketable and undesirable fish and fish of both legal and illegal size. Any part of the catch which cannot be used is considered by-catch, some of, killed accidentally by the trawling process. By-catch includes valued species such as dolphins, sea turtles, sharks, may include sublegal or immature individuals of the targeted species. Many studies have documented large volumes of by-catch. For example, researchers conducting a three-year study in the Clarence River found that an estimated 177 tons of by-catch were discarded each year. Size selectivity is controlled by the mesh size of the "cod-end"—the part of the trawl where fish are retained. Fishermen complain that mesh sizes which allow undersized fish to escape allow some catchable fish to escape. There are a number of "fixes", such as tying a rope around the "cod-end" to prevent the mesh from opening which have been developed to work around technical regulation of size selectivity.
One problem is. The capture of undesirable species is a recognized problem with all fishing methods and unites environmentalists, who do not want to see fish killed needlessly, fishermen, who do not want to waste their time sorting marketable fish from their catch. A number of methods to minimize this have been developed for use in trawling. Bycatch reduction grids or square mesh panels of net can be fitted to parts of the trawl, allowing certain species to escape while retaining others. Studies have suggested. Trawling is controversial because of its environmental impacts; because bottom trawling involves towing heavy fishing gear over the seabed, it can cause large-scale destruction on the ocean bottom, including coral shattering, damage to habitats and removal of seaweed. The primary sources of impact are the doors, which can weigh several tonnes and create furrows if dragged along the bottom, the footrope configuration, which remains in contact with the bottom across the entire lower edge of the net.
Depending on the configuration, the footrope may turn over large rocks or boulders dragging them along with the net, disturb or damage sessile organisms or rew
Charles Wyville Thomson
Sir Charles Wyville Thomson was a Scottish natural historian and marine zoologist. He served as the chief scientist on the Challenger expedition. Thomson was born at Bonsyde, in Linlithgow, West Lothian, on 5 March 1830, the son of Andrew Thomson, a surgeon in the service of the East India Company, Sarah Ann Drummond Smith, he was baptised Wyville Thomas Charles Thomson, only changed his name late in life, in 1876. He was educated under Charles Chalmers at Merchiston Castle School from 1845 studied medicine at the University of Edinburgh. However, his focus turned from medicine towards natural science, he joined the Botanical Society of Edinburgh in 1847, soon after became secretary to the Royal Physical Society of Edinburgh. In 1850 he was attending the botany class of John Hutton Balfour at the university. In 1850 he was appointed lecturer of botany, in 1851 professor of botany, at the University of Aberdeen. In 1853 he became a professor of natural history in Queen's College, Ireland, succeeding Professor Hincks.
A year he was nominated to the chair of mineralogy and geology at the Queen's University of Belfast. In 1855 he was elected a Fellow of the Royal Society of Edinburgh, his proposer being his former tutor, John Hutton Balfour, he served as the Society's Vice President from 1877 to 1882. He was elected a Fellow of the Royal Society of London in 1869. In 1860 was transferred to the chair of natural history at the same institution. In 1868 he assumed the duties of professor of botany at the Royal College of Science, in 1870 he received the natural history chair at the University of Edinburgh. In 1871–72 he served as President of the Botanical Society of Edinburgh. Wyville Thomson is remembered for his studies of the biological conditions of the deep seas. Being interested in crinoids, prompted by the results of the dredgings of Michael Sars in the deep sea off the Norwegian coasts, he persuaded the Royal Navy to grant him use of HMS Lightning and HMS Porcupine for deep sea dredging expeditions in the summers of 1868 and 1869.
They showed that animal life existed down to depths of 650 fathoms, that all marine invertebrate groups are present at this depth, that deep-sea temperatures are not as constant as had been supposed, but vary and indicate oceanic circulation. These results were described in The Depths of the Sea, which he published in 1873; the remarkable hydrographic and zoological results which Wyville Thomson had demonstrated, in addition to the growing demands of ocean telegraphy, soon led to the Royal Navy to grant use of HMS Challenger for a global expedition. Wyville Thomson was selected as chief scientist, the ship sailed on 23 December 1872; the Challenger Expedition was deemed a great success, on his return Wyville Thomson received a number of academic honours, as well as a knighthood. In 1873 he published "Depths of the Sea" based on initial findings from the expedition. In 1880 he published two volumes, The Voyage of the Challenger in the Atlantic, a preliminary account of the results of the voyage.
He spent the next two years working on administrative duties connected with the publication of the full monograph of the voyage. Wyville Thomson had a strung mentality, his health was poor throughout his life, he found dealing with publishers over the requirements of publishing 50 volumes of detailed illustration and scientific description enormously stressful. In 1879 he ceased to perform his university duties, gave up overseeing the reports of the expedition in 1881, took to his bed and died a broken man at Bonsyde on 10 March 1882; the publishing was completed by his friend and colleague Sir John Murray. Wyville Thomson is commemorated in the stained glass window above the altar in St. Michael's Parish Church and his headstone is in the churchyard. In addition the Wyville-Thomson Ridge in the North Atlantic Ocean is named after him. Thomson had criticized natural selection, stating it was not enough to explain the evolution of species. Replying in the Nature journal, Charles Darwin commented that "I am sorry to find that Sir Wyville Thomson does not under stand the principle of natural selection, as explained by Mr. Wallace and myself...
Can Sir Wyville Thomson name any one who has said that the evolution of species depends only on natural selection?" The Depths of the Sea The Voyage of the Challenger In 1853 he married Jane Ramage Dawson. They were parents to Frank Wyville Thomson FRSE. European and American voyages of scientific exploration This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed.. "Thomson, Sir Charles Wyville". Encyclopædia Britannica. Cambridge University Press. Works by or about Charles Wyville Thomson at Internet Archive "Thomson, Charles Wyville". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900. Charles Wyville Thomson; the Depths of the Sea: an account of the general results of the dredging cruises of H. M. SS.'Porcupine' and'Lightning' during the summers of 1868, 1869, 1870, under the scientific direction of Dr. Carpenter, F. R. S. J. Gwyn Jeffreys, F. R. S. and Dr. Wyville Thomson, F. R. S. Internet Archive
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
Sediment is a occurring material, broken down by processes of weathering and erosion, is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation and if buried, may become sandstone and siltstone. Sediments are most transported by water, but wind and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian deposition. Glacial moraine deposits and till are ice-transported sediments. Sediment can be classified based on its grain composition. Sediment size is measured on a log base 2 scale, called the "Phi" scale, which classifies particles by size from "colloid" to "boulder". Composition of sediment can be measured in terms of: parent rock lithology mineral composition chemical make-up.
This leads to an ambiguity in which clay can be used as a composition. Sediment is transported based on the strength of the flow that carries it and its own size, volume and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, while larger or denser particles will be more to fall through the flow. Rivers and streams carry sediment in their flows; this sediment can be in a variety of locations within the flow, depending on the balance between the upwards velocity on the particle, the settling velocity of the particle. These relationships are shown in the following table for the Rouse number, a ratio of sediment fall velocity to upwards velocity. Rouse = Settling velocity Upwards velocity from lift and drag = w s κ u ∗ where w s is the fall velocity κ is the von Kármán constant u ∗ is the shear velocity If the upwards velocity is equal to the settling velocity, sediment will be transported downstream as suspended load. If the upwards velocity is much less than the settling velocity, but still high enough for the sediment to move, it will move along the bed as bed load by rolling and saltating.
If the upwards velocity is higher than the settling velocity, the sediment will be transported high in the flow as wash load. As there are a range of different particle sizes in the flow, it is common for material of different sizes to move through all areas of the flow for given stream conditions. Sediment motion can create self-organized structures such as ripples, dunes, or antidunes on the river or stream bed; these bedforms are preserved in sedimentary rocks and can be used to estimate the direction and magnitude of the flow that deposited the sediment. Overland flow can transport them downslope; the erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions. If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion. If overland flow is directly responsible for sediment entrainment but does not form gullies, it is called "sheet erosion". If the flow and the substrate permit channelization, gullies may form.
The major fluvial environments for deposition of sediments include: Deltas Point bars Alluvial fans Braided rivers Oxbow lakes Levees Waterfalls Wind results in the transportation of fine sediment and the formation of sand dune fields and soils from airborne dust. Glaciers carry a wide range of sediment sizes, deposit it in moraines; the overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation. This expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow; this equation is important in that changes in the power of the flow change the ability of the flow to carry sediment, this is reflected in the patterns of erosion and deposition observed throughout a stream. This can be localized, due to small obstacles. Erosion and deposition can be regional. Deposition can occur due to dam emplacement that causes the river to pool and deposit its entire load, or due to base level rise.
Seas and lakes accumulate sediment over time. The sediment can consist of terrigenous material, which originates on land, but may be deposited in either terrestrial, marine, or lacustrine environments, or of sediments originating in the body of water. Terrigenous material is supplied by nearby rivers and streams or reworked marine sediment. In the mid-ocean, the exoskeletons of dead organisms are responsible for sediment accumulation. Deposited sediments are the source of sedimentary rocks, which can contain fossils of