In earth science, erosion is the action of surface processes that removes soil, rock, or dissolved material from one location on the Earth's crust, transports it to another location. This natural process is caused by the dynamic activity of erosive agents, that is, ice, air, plants and humans. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind erosion, zoogenic erosion, anthropogenic erosion; the particulate breakdown of rock or soil into clastic sediment is referred to as physical or mechanical erosion. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Natural rates of erosion are controlled by the action of geological weathering geomorphic drivers, such as rainfall; the rates at which such processes act control. Physical erosion proceeds fastest on steeply sloping surfaces, rates may be sensitive to some climatically-controlled properties including amounts of water supplied, wind speed, wave fetch, or atmospheric temperature.
Feedbacks are possible between rates of erosion and the amount of eroded material, carried by, for example, a river or glacier. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, which control the arrival and emplacement of material at a new location. While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the natural rate of erosion in the region. Excessive erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the eventual end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses.
Water and wind erosion are the two primary causes of land degradation. Intensive agriculture, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, sheet erosion, rill erosion, gully erosion. Splash erosion is seen as the first and least severe stage in the soil erosion process, followed by sheet erosion rill erosion and gully erosion. In splash erosion, the impact of a falling raindrop creates a small crater in the soil, ejecting soil particles; the distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs.
If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope. Sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are of the order of a few centimetres or less and along-channel slopes may be quite steep; this means that rills exhibit hydraulic physics different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and flows in narrow channels during or after heavy rains or melting snow, removing soil to a considerable depth. Valley or stream erosion occurs with continued water flow along a linear feature; the erosion is both downward, deepening the valley, headward, extending the valley into the hillside, creating head cuts and steep banks.
In the earliest stage of stream erosion, the erosive activity is dominantly vertical, the valleys have a typical V cross-section and the stream gradient is steep. When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain; the stream gradient becomes nearly flat, lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far the most erosion occurs during times of flood when more and faster-moving water is available to carry a larger sediment load. In such processes, it is not the water alone
Alabama is a state in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east and the Gulf of Mexico to the south, Mississippi to the west. Alabama is the 30th largest by area and the 24th-most populous of the U. S. states. With a total of 1,500 miles of inland waterways, Alabama has among the most of any state. Alabama is nicknamed the Yellowhammer State, after the state bird. Alabama is known as the "Heart of Dixie" and the "Cotton State"; the state tree is the longleaf pine, the state flower is the camellia. Alabama's capital is Montgomery; the largest city by population is Birmingham. The oldest city is Mobile, founded by French colonists in 1702 as the capital of French Louisiana. From the American Civil War until World War II, like many states in the southern U. S. suffered economic hardship, in part because of its continued dependence on agriculture. Similar to other former slave states, Alabamian legislators employed Jim Crow laws to disenfranchise and otherwise discriminate against African Americans from the end of the Reconstruction Era up until at least the 1970s.
Despite the growth of major industries and urban centers, white rural interests dominated the state legislature from 1901 to the 1960s. During this time, urban interests and African Americans were markedly under-represented. Following World War II, Alabama grew as the state's economy changed from one based on agriculture to one with diversified interests; the state's economy in the 21st century is based on management, finance, aerospace, mineral extraction, education and technology. The European-American naming of the Alabama River and state was derived from the Alabama people, a Muskogean-speaking tribe whose members lived just below the confluence of the Coosa and Tallapoosa rivers on the upper reaches of the river. In the Alabama language, the word for a person of Alabama lineage is Albaamo; the suggestion that "Alabama" was borrowed from the Choctaw language is unlikely. The word's spelling varies among historical sources; the first usage appears in three accounts of the Hernando de Soto expedition of 1540: Garcilaso de la Vega used Alibamo, while the Knight of Elvas and Rodrigo Ranjel wrote Alibamu and Limamu in transliterations of the term.
As early as 1702, the French called the tribe the Alibamon, with French maps identifying the river as Rivière des Alibamons. Other spellings of the name have included Alibamu, Albama, Alibama, Alabamu, Allibamou. Sources disagree on the word's meaning; some scholars suggest the word comes from amo. The meaning may have been "clearers of the thicket" or "herb gatherers", referring to clearing land for cultivation or collecting medicinal plants; the state has numerous place names of Native American origin. However, there are no correspondingly similar words in the Alabama language. An 1842 article in the Jacksonville Republican proposed it meant "Here We Rest." This notion was popularized in the 1850s through the writings of Alexander Beaufort Meek. Experts in the Muskogean languages have not found any evidence to support such a translation. Indigenous peoples of varying cultures lived in the area for thousands of years before the advent of European colonization. Trade with the northeastern tribes by the Ohio River began during the Burial Mound Period and continued until European contact.
The agrarian Mississippian culture covered most of the state from 1000 to 1600 AD, with one of its major centers built at what is now the Moundville Archaeological Site in Moundville, Alabama. This is the second-largest complex of the classic Middle Mississippian era, after Cahokia in present-day Illinois, the center of the culture. Analysis of artifacts from archaeological excavations at Moundville were the basis of scholars' formulating the characteristics of the Southeastern Ceremonial Complex. Contrary to popular belief, the SECC appears to have no direct links to Mesoamerican culture, but developed independently; the Ceremonial Complex represents a major component of the religion of the Mississippian peoples. Among the historical tribes of Native American people living in present-day Alabama at the time of European contact were the Cherokee, an Iroquoian language people. While part of the same large language family, the Muskogee tribes developed distinct cultures and languages. With exploration in the 16th century, the Spanish were the first Europeans to reach Alabama.
The expedition of Hernando de Soto passed through Mabila and other parts of the state in 1540. More than 160 years the French founded the region's first European settlement at Old Mobile in 1702; the city was moved to the current site of Mobile in 1711. This area was claimed by the French from 1702 to 1763 as part of La Louisiane. After the French lost to the British in the Seven Years' War, it became part of British West Florida from 1763 to 1783. After the United States victory in the American Revolutionary War, the territory was divided between the United States and Spain; the latter retained control of this western territory from 1783 until the surrender of the Spanish garrison at Mobile to U. S. forces on April 13, 1813. Thomas Bassett, a loyalist to the British monarchy during the Revolutionary era, was one of the earliest white settlers in the state
A valley is a low area between hills or mountains with a river running through it. In geology, a valley or dale is a depression, longer than it is wide; the terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys. Most valleys belong to one of these two main types or a mixture of them, at least with respect to the cross section of the slopes or hillsides. A valley in its broadest geographic sense is known as a dale. Other terms used for valleys are: Vale: A valley. Dell: A small and wooded valley. Glen: A long valley bounded by sloped concave sides. Strath: A wide, flat valley through which a river runs. Mountain cove: A small valley, closed at one or both ends, in the central or southern Appalachian Mountains which sometimes results from the erosion of a geologic window. Hollow: A term used sometimes for a small valley surrounded by mountains or ridges. Cwm: A deep, narrow valley. A steephead valley is a deep, flat bottomed valley with an abrupt ending. Erosional valley: A valley formed by erosion.
Structural valley: A valley formed by geologic events such as drop faults or the rise of highlands. Dry valley: A valley not created by sustained surface water flow. Longitudinal valley: An elongated valley found between two parallel mountain chains. Similar geological structures, such as canyons, gorges, gullies and kloofs, are not referred to as valleys. A valley formed by flowing water, called fluvial valley or river valley, is V-shaped; the exact shape will depend on the characteristics of the stream flowing through it. Rivers with steep gradients, as in mountain ranges, produce a bottom. Shallower slopes may produce gentler valleys. However, in the lowest stretch of a river, where it approaches its base level, it begins to deposit sediment and the valley bottom becomes a floodplain; some broad V examples are: North America: Black Canyon of the Gunnison National Park, others in Grand Canyon NP Europe: Austria: narrow passages of upper Inn valley, affluents of Enns Switzerland: Napf region, Zurich Oberland, Engadin Germany: affluents to the middle reaches of Rhine and MoselSome of the first human complex societies originated in river valleys, such as that of the Nile, Tigris-Euphrates, Ganges, Yellow River and arguably Amazon.
In prehistory, the rivers were used as a source of fresh water and food, as well as a place to wash and a sewer. The proximity of water moderated temperature extremes and provided a source for irrigation, stimulating the development of agriculture. Most of the first civilizations developed from these river valley communities. In geography, a vale is a wide river valley with a wide flood plain or flat valley bottom. In Southern England, vales occur between the escarpment slopes of pairs of chalk formations, where the chalk dome has been eroded, exposing less resistant underlying rock claystone. Rift valleys, such as the Albertine Rift and Gregory Rift are formed by the expansion of the Earth's crust due to tectonic activity beneath the Earth's surface. There are various forms of valley associated with glaciation that may be referred to as glacial valleys. A valley carved by glaciers is U-shaped and resembles a trough; this trough valley becomes visible upon the recession of the glacier. When the ice recedes or thaws, the valley remains littered with small boulders that were transported within the ice.
Floor gradient does not affect the valley's shape, it is the glacier's size. Continuously flowing glaciers – in the ice age – and large-sized glaciers carve wide, deep incised valleys, sometimes with valley steps that reflect differing erosion rates. Examples of U-shaped valleys are found in every mountainous region that has experienced glaciation during the Pleistocene ice ages. Most present U-shaped valleys started as V-shaped before glaciation; the glaciers carved it out wider and deeper changing the shape. This proceeds through the glacial erosion processes of glaciation and abrasion, which results in large rocky material being carried in the glacier. A material called; as the ice melts and retreats, the valley is left with steep sides and a wide, flat floor. A river or stream may remain in the valley; this replaces the original stream or river and is known as a misfit stream because it is smaller than one would expect given the size of its valley. Other interesting glacially carved valleys include: Yosemite Valley Side valleys of the Austrian river Salzach for their parallel directions and hanging mouths.
Some Scottish glens full with flowers. That of the St. Mary River in Glacier National Park in Montana, USA. A tunnel valley is a large, long, U-shaped valley cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and covering portions of all continents during past glacial ages. A tunnel valley can be up to 100 km, 4 km wide, 400 m deep. Tunnel valleys were formed by subglacial erosion by water, they served as subglacial drainage pathways carrying large volumes of melt water. Their cross-sections exhibit steep-sided flanks similar to fjord walls, their flat bottoms are typical of subglacial glacial erosion. In northern Central Europe, the Scandinavian ice sheet during the various ice ages advanced uphill against the lie of the land; as a result, its meltwaters flowed parallel to the ice margin to reach the North Sea basin, formin
Pennsylvania the Commonwealth of Pennsylvania, is a state located in the northeastern and Mid-Atlantic regions of the United States. The Appalachian Mountains run through its middle; the Commonwealth is bordered by Delaware to the southeast, Maryland to the south, West Virginia to the southwest, Ohio to the west, Lake Erie and the Canadian province of Ontario to the northwest, New York to the north, New Jersey to the east. Pennsylvania is the 33rd-largest state by area, the 6th-most populous state according to the most recent official U. S. Census count in 2010, it is the 9th-most densely populated of the 50 states. Pennsylvania's two most populous cities are Philadelphia, Pittsburgh; the state capital and its 10th largest city is Harrisburg. Pennsylvania has 140 miles of waterfront along the Delaware Estuary; the state is one of the 13 original founding states of the United States. Part of Pennsylvania, together with the present State of Delaware, had earlier been organized as the Colony of New Sweden.
It was the second state to ratify the United States Constitution, on December 12, 1787. Independence Hall, where the United States Declaration of Independence and United States Constitution were drafted, is located in the state's largest city of Philadelphia. During the American Civil War, the Battle of Gettysburg was fought in the south central region of the state. Valley Forge near Philadelphia was General Washington's headquarters during the bitter winter of 1777–78. Pennsylvania is 170 miles north to south and 283 miles east to west. Of a total 46,055 square miles, 44,817 square miles are land, 490 square miles are inland waters, 749 square miles are waters in Lake Erie, it is the 33rd-largest state in the United States. Pennsylvania has 51 miles of coastline along Lake Erie and 57 miles of shoreline along the Delaware Estuary. Of the original Thirteen Colonies, Pennsylvania is the only state that does not border the Atlantic Ocean; the boundaries of the state are the Mason–Dixon line to the south, the Twelve-Mile Circle on the Pennsylvania-Delaware border, the Delaware River to the east, 80° 31' W to the west and the 42° N to the north, with the exception of a short segment on the western end, where a triangle extends north to Lake Erie.
Cities include Philadelphia, Reading and Lancaster in the southeast, Pittsburgh in the southwest, the tri-cities of Allentown and Easton in the central east. The northeast includes the former anthracite coal mining cities of Scranton, Wilkes-Barre and Hazleton. Erie is located in the northwest. State College serves the central region while Williamsport serves the commonwealth's north-central region as does Chambersburg the south-central region, with York and the state capital Harrisburg on the Susquehanna River in the east-central region of the Commonwealth and Altoona and Johnstown in the west-central region; the state has five geographical regions, namely the Allegheny Plateau and Valley, Atlantic Coastal Plain and the Erie Plain. New York Ontario Maryland Delaware West Virginia New Jersey Ohio Pennsylvania's diverse topography produces a variety of climates, though the entire state experiences cold winters and humid summers. Straddling two major zones, the majority of the state, with the exception of the southeastern corner, has a humid continental climate.
The southern portion of the state has a humid subtropical climate. The largest city, has some characteristics of the humid subtropical climate that covers much of Delaware and Maryland to the south. Summers are hot and humid. Moving toward the mountainous interior of the state, the winter climate becomes colder, the number of cloudy days increases, snowfall amounts are greater. Western areas of the state locations near Lake Erie, can receive over 100 inches of snowfall annually, the entire state receives plentiful precipitation throughout the year; the state may be subject to severe weather from spring through summer into fall. Tornadoes occur annually in the state, sometimes in large numbers, such as 30 recorded tornadoes in 2011; as of 1600, the tribes living in Pennsylvania were the Algonquian Lenape, the Iroquoian Susquehannock & Petun and the Siouan Monongahela Culture, who may have been the same as a little known tribe called the Calicua, or Cali. Other tribes who entered the region during the colonial era were the Trockwae, Saponi, Nanticoke, Conoy Piscataway, Iroquois Confederacy—possibly among others.
Other tribes, like the Erie, may have once held some land in Pennsylvania, but no longer did so by the year 1600. Both the Dutch and the English claimed both sides of the Delaware River as part of their colonial lands in America; the Dutch were the first to take possession. By June 3, 1631, the Dutch had begun settling the Delmarva Peninsula by establishing the Zwaanendael Colony on the site of present-day Lewes, Delaware. In 1638, Sweden established the New Sweden Colony, in the region of Fort Christina, on the site of present-day Wilmington, Delaware. New Sweden claimed and, for the most part, controlled the lower Delaware River region (parts of present-day Delaware, New Jersey, Pe
The Allegheny Front is the major southeast- or east-facing escarpment in the Allegheny Mountains in southern Pennsylvania, western Maryland, eastern West Virginia, USA. The Allegheny Front forms the boundary between the Ridge-and-Valley Appalachians to its east and the Appalachian Plateau to its west; the Front is associated with the Appalachian Mountains' Eastern Continental Divide, which in this area divides the waters of the Ohio/Mississippi river system, flowing to the Gulf of Mexico, from rivers flowing into Chesapeake Bay and from there into the Atlantic Ocean. However, the Front and the Divide do not always coincide; the Allegheny Front is one of the windiest spots east of the Mississippi, leading to the recent establishment of wind farming there. The Allegheny Front forms part of the Appalachian Structural Front, separating the Appalachian Plateau from the Appalachians' Ridge and Valley Province; the various other escarpments along this structural feature include the Catskill Escarpment to the northeast and the Cumberland Escarpment to the southwest.
The Allegheny Front itself extends for about 180 miles southwesterly from south-central Pennsylvania through western Maryland divides the eastern panhandle of West Virginia from the rest of that state. The name "Allegheny Front" is applied to the escarpment throughout much of its extent, although it is little used in Maryland; the highest part of the crest of the Allegheny Front is its southernmost high point, Mount Porte Crayon at 4,770 feet, on the Pendleton/Randolph county line in West Virginia. Its lowest point, 790 feet, is along the North Branch of the Potomac River near Keyser, West Virginia. Other high points along the Front include the Dolly Sods area in West Virginia, a broad, rocky plateau at an elevation of about 4,000 feet. Local segments of the Eastern Continental Divide pass within a few miles of the Allegheny Front, in many places coincide with it. A number of eastward-flowing creeks and rivers have their headwaters incised into Allegheny Front, displacing the Divide westward from the Front, including the North Branch of the Potomac River west of Cumberland, which originates well into the Appalachian Plateau at the Fairfax Stone, just south of Maryland's southwestern tip.
No waterway crosses the Front from east to west. The Allegheny Plateau, the Eastern drainage divide, the emphasis the cartographer placed on the Allegheny Front is obvious in this minimalist styled 19th century map. So settled were the lands, the cartographer has traced known trails proven wagon tracks throughout, exposed the unsettled lands and shows their convergence through the few climbable gaps in the Allegheny Front. Note this map is three years after the legislation authorizing the Allegheny Portage Railroad and the Main Line of Public Works and Pennsylvania Canal System that would connect Philadelphia to the Ohio River; the portage railroad ascends the gap due east of the mining town of Ebensburg, PA. The Allegheny Front begins in central Pennsylvania just northwest of the town of Lock Haven and extends southwest paralleling, Bald Eagle Mountain, Brush Mountain to its east; the Front continues to a point a little north of the Pennsylvania/Maryland boundary where it is offset about 10 miles to the east as it changes from the bold escarpment that characterized it west of Altoona to its more gentle rise in Maryland.
Across the Mason–Dixon line in Maryland, the Front becomes Dans Mountain, west of Cumberland, which reaches 2,895 feet in elevation at Dan's Rock. Along Maryland's southern border, the North Branch of the Potomac River cuts down through the Front at 790 feet just west of Keyser, West Virginia. South of the Potomac, in West Virginia, the Front continues through the Mount Storm area passes along the eastern edge of Dolly Sods, a wide plateau of Pottsville conglomerate bedrock at about 4,000 feet elevation. From the Sods, the front continues southward as an steep escarpment west of the North Fork of the South Branch of the Potomac River, with the Roaring Plains continuing the high plateaus of the Dolly Sods area along the escarpment's crest; the Allegheny Front's southern end is Mount Porte Crayon, after which the land drops steeply to Seneca Creek, west of Seneca Rocks. South of Mount Porte Crayon and Seneca Creek, the Appalachian Structural Front is less unified. Pottsville-capped Spruce Mountain and east of Seneca Creek, continues the Allegheny Front's geology southward.
Steep escarpments sharing much of the same geologic structure are present nearby along the eastern slopes of Allegheny Mountain and Back Allegheny Mountain, but these mountains lack the Pottsville caps characteristic of the Allegheny Front. Allegheny Mountain's long, nearly level crest is about 4,000 to 4,200 feet in elevation, with Paddy Knob reach
In structural geology, a syncline is a fold with younger layers closer to the center of the structure. A synclinorium is a large syncline with superimposed smaller folds. Synclines are a downward fold, termed a synformal syncline, but synclines that point upwards can be found when strata have been overturned and folded. On a geologic map, synclines are recognized as a sequence of rock layers, with the youngest at the fold's center or hinge and with a reverse sequence of the same rock layers on the opposite side of the hinge. If the fold pattern is circular or elongate, the structure is a basin. Folds form during crustal deformation as the result of compression that accompanies orogenic mountain building. Powder River Basin, Wyoming, US Sideling Hill roadcut along Interstate 68 in western Maryland, US, where the Rockwell Formation and overlying Purslane Sandstone are exposed Saou, a commune in the Drôme department in southeastern France The Southland Syncline in the southeastern corner of the South Island of New Zealand, including The Catlins and the Hokonui Hills Strathmore, Angus Syncline, Scotland Anticline Homocline Monocline Ridge-and-Valley Appalachians
Transport or transportation is the movement of humans and goods from one location to another. In other words the action of transport is defined as a particular movement of an organism or thing from a point A to the Point B. Modes of transport include air, water, cable and space; the field can be divided into infrastructure and operations. Transport is important because it enables trade between people, essential for the development of civilizations. Transport infrastructure consists of the fixed installations, including roads, airways, waterways and pipelines and terminals such as airports, railway stations, bus stations, trucking terminals, refueling depots and seaports. Terminals may be used both for maintenance. Vehicles traveling on these networks may include automobiles, buses, trucks, watercraft and aircraft. Operations deal with the way the vehicles are operated, the procedures set for this purpose, including financing and policies. In the transport industry and ownership of infrastructure can be either public or private, depending on the country and mode.
Passenger transport may be public. Freight transport has become focused on containerization, although bulk transport is used for large volumes of durable items. Transport plays an important part in economic growth and globalization, but most types cause air pollution and use large amounts of land. While it is subsidized by governments, good planning of transport is essential to make traffic flow and restrain urban sprawl. Humans' first means of transport involved walking and swimming; the domestication of animals introduced a new way to lay the burden of transport on more powerful creatures, allowing the hauling of heavier loads, or humans riding animals for greater speed and duration. Inventions such as the wheel and the sled helped make animal transport more efficient through the introduction of vehicles. Water transport, including rowed and sailed vessels, dates back to time immemorial, was the only efficient way to transport large quantities or over large distances prior to the Industrial Revolution.
The first forms of road transport involved animals, such as horses, oxen or humans carrying goods over dirt tracks that followed game trails. Many early civilizations, including those in Mesopotamia and the Indus Valley, constructed paved roads. In classical antiquity, the Persian and Roman empires built stone-paved roads to allow armies to travel quickly. Deep roadbeds of crushed stone underneath kept such roads dry; the medieval Caliphate built tar-paved roads. The first watercraft were canoes cut out from tree trunks. Early water transport was accomplished with ships that were either rowed or used the wind for propulsion, or a combination of the two; the importance of water has led to most cities that grew up as sites for trading being located on rivers or on the sea-shore at the intersection of two bodies of water. Until the Industrial Revolution, transport remained slow and costly, production and consumption gravitated as close to each other as feasible; the Industrial Revolution in the 19th century saw a number of inventions fundamentally change transport.
With telegraphy, communication became independent of the transport of physical objects. The invention of the steam engine followed by its application in rail transport, made land transport independent of human or animal muscles. Both speed and capacity increased allowing specialization through manufacturing being located independently of natural resources; the 19th century saw the development of the steam ship, which sped up global transport. With the development of the combustion engine and the automobile around 1900, road transport became more competitive again, mechanical private transport originated; the first "modern" highways were constructed during the 19th century with macadam. Tarmac and concrete became the dominant paving materials. In 1903 the Wright brothers demonstrated the first successful controllable airplane, after World War I aircraft became a fast way to transport people and express goods over long distances. After World War II the automobile and airlines took higher shares of transport, reducing rail and water to freight and short-haul passenger services.
Scientific spaceflight began in the 1950s, with rapid growth until the 1970s, when interest dwindled. In the 1950s the introduction of containerization gave massive efficiency gains in freight transport, fostering globalization. International air travel became much more accessible in the 1960s with the commercialization of the jet engine. Along with the growth in automobiles and motorways and water transport declined in relative importance. After the introduction of the Shinkansen in Japan in 1964, high-speed rail in Asia and Europe started attracting passengers on long-haul routes away from the airlines. Early in U. S. history, private joint-stock corporations owned most aqueducts, canals, railroads and tunnels. Most such transport infrastructure came under government control in the late 19th and early 20th centuries, culminating in the nationalization of inter-city passenger rail-service with the establishment of Amtrak. However, a movement to privatize roads and other infrastructure has gained some ground and adherents.
A mode of transport is a solution that makes use of a particular type of vehicle and operation. The transport of a person or of cargo may invol