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An artesian well is a 
Not all aquifers are artesian (i.e., water table aquifers occur where the groundwater level at the top of the aquifer is at equilibrium with atmospheric pressure). Aquifers recharge when the water table at its recharge zone is at a higher
Video of an artesian aquifer releasing water under its own pressure
{{DEFAULTSORT:Artesian Aquifer Aquifers Hydrology Water wells
An artesian well is a well
A well is an excavation or structure created on the earth by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The ...
that brings groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...
to the surface without pumping because it is under pressure within a body of rock or sediment known as an aquifer
An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...
. When trapped water in an aquifer is surrounded by layers of impermeable rock or clay, which apply positive pressure to the water, it is known as an artesian aquifer. If a well were to be sunk into an artesian aquifer, water in the well-pipe would rise to a height corresponding to the point where hydrostatic equilibrium
In fluid mechanics, hydrostatic equilibrium, also called hydrostatic balance and hydrostasy, is the condition of a fluid or plastic solid at rest, which occurs when external forces, such as gravity, are balanced by a pressure-gradient force. I ...
is reached.
A well drilled into such an aquifer is called an ''artesian well''. If water reaches the ground surface under the natural pressure of the aquifer, the well is termed a ''flowing artesian well''.
Fossil water
Fossil water, fossil groundwater, or paleowater is an ancient body of water that has been contained in some undisturbed space, typically groundwater in an aquifer, for millennia. Other types of fossil water can include subglacial lakes, such as An ...
aquifers can also be artesian if they are under sufficient pressure from the surrounding rocks, similar to how many newly tapped oil well
An oil well is a drillhole boring in Earth that is designed to bring petroleum oil hydrocarbons to the surface. Usually some natural gas is released as associated petroleum gas along with the oil. A well that is designed to produce only gas m ...
s are pressurized.
Not all aquifers are artesian (i.e., water table aquifers occur where the groundwater level at the top of the aquifer is at equilibrium with atmospheric pressure). Aquifers recharge when the water table at its recharge zone is at a higher elevation
The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...
than the head of the well.
History
The first mechanically accurate explanation for artesian wells was given byAl-Biruni
Abu Rayhan Muhammad ibn Ahmad al-Biruni (; ; 973after 1050), known as al-Biruni, was a Khwarazmian Iranian scholar and polymath during the Islamic Golden Age. He has been called variously "Father of Comparative Religion", "Father of modern ...
. Artesian wells were named after Artois
Artois ( , ; ; Picard: ''Artoé;'' English adjective: ''Artesian'') is a region of northern France. Its territory covers an area of about 4,000 km2 and it has a population of about one million. Its principal cities include Arras (Dutch: ...
in France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
, where many artesian wells were drilled by Carthusian
The Carthusians, also known as the Order of Carthusians (), are a Latin enclosed religious order of the Catholic Church. The order was founded by Bruno of Cologne in 1084 and includes both monks and nuns. The order has its own rule, called th ...
monks from 1126. Frances Gies and Joseph Gies, ''Cathedral, Forge, and Waterwheel'' subtitled "Technology and Invention in the Middle Ages". Harper Perennial, 1995 , page 112.
See also
*Fluid mechanics
Fluid mechanics is the branch of physics concerned with the mechanics of fluids (liquids, gases, and plasma (physics), plasmas) and the forces on them.
Originally applied to water (hydromechanics), it found applications in a wide range of discipl ...
* Great Artesian Basin
* Hydrogeology
Hydrogeology (''hydro-'' meaning water, and ''-geology'' meaning the study of the Earth) is the area of geology that deals with the distribution and movement of groundwater in the soil and rock (geology), rocks of the Earth's crust (ge ...
* Qanat
A qanāt () or kārīz () is a water supply system that was developed in ancient Iran for the purpose of transporting usable water to the surface from an aquifer or a well through an underground aqueduct. Originating approximately 3,000 years ...
*Spring (hydrology)
A spring is a natural exit point at which groundwater emerges from an aquifer and flows across the ground surface as surface water. It is a component of the hydrosphere, as well as a part of the water cycle. Springs have long been important f ...
* List of artesian wells in the United States
* Drilled wells (for bore water mechanics)
References
External links
Video of an artesian aquifer releasing water under its own pressure
{{DEFAULTSORT:Artesian Aquifer Aquifers Hydrology Water wells