A lake is an area filled with water, localized in a basin, that is surrounded by land, apart from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, and therefore are distinct from lagoons, and are also larger and deeper than ponds, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which are usually flowing. Most lakes are fed and drained by rivers and streams.
Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. In some parts of the world there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will slowly fill in with sediments or spill out of the basin containing them.
Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, or for aesthetic, recreational purposes, or other activities.
The word lake comes from Middle English lake ("lake, pond, waterway"), from Old English lacu ("pond, pool, stream"), from Proto-Germanic *lakō ("pond, ditch, slow moving stream"), from the Proto-Indo-European root *leǵ- ("to leak, drain"). Cognates include Dutch laak ("lake, pond, ditch"), Middle Low German lāke ("water pooled in a riverbed, puddle") as in: de:Wolfslake, de:Butterlake, German Lache ("pool, puddle"), and Icelandic lækur ("slow flowing stream"). Also related are the English words leak and leach.
There is considerable uncertainty about defining the difference between lakes and ponds, and no current internationally accepted definition of either term across scientific disciplines or political boundaries exists. For example, limnologists have defined lakes as water bodies which are simply a larger version of a pond, which can have wave action on the shoreline or where wind-induced turbulence plays a major role in mixing the water column. None of these definitions completely excludes ponds and all are difficult to measure. For this reason, simple size-based definitions are increasingly used to separate ponds and lakes. Definitions for lake range in minimum sizes for a body of water from 2 hectares (5 acres):331 to 8 hectares (20 acres) (see also the definition of "pond"). Charles Elton, one of the founders of ecology, regarded lakes as waterbodies of 40 hectares (99 acres) or more. The term lake is also used to describe a feature such as Lake Eyre, which is a dry basin most of the time but may become filled under seasonal conditions of heavy rainfall. In common usage, many lakes bear names ending with the word pond, and a lesser number of names ending with lake are in quasi-technical fact, ponds. One textbook illustrates this point with the following: "In Newfoundland, for example, almost every lake is called a pond, whereas in Wisconsin, almost every pond is called a lake."
The majority of lakes on Earth are freshwater, and most lie in the Northern Hemisphere at higher latitudes. Canada, with a deranged drainage system has an estimated 31,752 lakes larger than 3 square kilometres (1.2 sq mi) and an unknown total number of lakes, but is estimated to be at least 2 million. Finland has 187,888 lakes 500 square metres (5,400 sq ft) or larger, of which 56,000 are large (10,000 square metres (110,000 sq ft) or larger).
Most lakes have at least one natural outflow in the form of a river or stream, which maintain a lake's average level by allowing the drainage of excess water. Some lakes do not have a natural outflow and lose water solely by evaporation or underground seepage or both. They are termed endorheic lakes.
Evidence of extraterrestrial lakes exists; "definitive evidence of lakes filled with methane" was announced by NASA as returned by the Cassini Probe observing the moon Titan, which orbited the planet Saturn.
Globally, lakes are greatly outnumbered by ponds: of an estimated 304 million standing water bodies worldwide, 91% are 1 hectare (2.5 acres) or less in area (see definition of ponds). Small lakes are also much more numerous than large lakes: in terms of area, one-third of the world's standing water is represented by lakes and ponds of 10 hectares (25 acres) or less. However, large lakes account for much of the area of standing water with 122 large lakes of 1,000 square kilometres (390 sq mi, 100,000 ha, 247,000 acres) or more representing about 29% of the total global area of standing inland water.
Tectonic lakes are lakes formed by the deformation and resulting lateral and vertical movements of the Earth’s crust. These movements include faulting, tilting, folding, and warping. Some of the well-known and largest lakes on Earth are rift lakes occupying rift valleys, e.g. Central African Rift lakes and Lake Baikal. Other well-known tectonic lakes, Caspian Sea, the Sea of Aral, and other lakes from the Pontocaspian occupy basins that have been separated from the sea by the tectonic uplift of the sea floor above sea level.
Often, the tectonic action of crustal extension has created an alternating series of parallel grabens and horsts that form elongate basins alternating with mountain ranges. Not only does this promote the creation of lakes by the disruption of preexisting drainage networks, it also creates within arid regions endorheic basins that containing salt lakes (also called saline lakes). They form where there is no natural outlet, a high evaporation rate and the drainage surface of the water table has a higher-than-normal salt content. Examples of these salt lakes include Great Salt Lake and the Dead Sea. Another type of tectonic lake caused by faulting is sag ponds.
Volcanic lakes are lakes that occupy either local depressions, e.g. craters and maars or larger basins, e.g. calderas, created by volcanism. Crater lakes are formed in volcanic craters and calderas, which fill up with precipitation more rapidly than they empty via either evaporation, groundwater discharge, or combination of both. Sometimes the latter are called caldera lakes, although often no distinction is made. An example is Crater Lake in Oregon, in the caldera of Mount Mazama. The caldera was created in a massive volcanic eruption that led to the subsidence of Mount Mazama around 4860 BCE. Other volcanic lakes are created when either rivers or streams are dammed by lava flows or volcanic lahars. The basin which is now Malheur Lake, Oregon was created when a lava flow dammed the Malheur River.
Glacial lakes are lakes created by the direct action of glaciers and continental ice sheets. A wide variety of glacial processes create enclosed basins. As a result, there are a wide variety of different types of glacial lakes and it is often difficult to define clear-cut distinctions between different types of glacial lakes and lakes influenced by other activities. The general types of glacial lakes that have recognized are lakes in direct contact with ice; glacially carved rock basins and depressions; morainic and outwash lakes; and glacial drift basins. Glacial lakes are the most numerous lakes in the world. Most lakes in northern Europe and North America have been either influenced or created by the latest, but not last, glaciation, to have covered the region. Glacial lakes include proglacial lakes, subglacial lakes, finger lakes, and epishelf lakes. Epishelf lakes are highly stratified lakes in which a layer of freshwater, derived from ice and snow melt, is dammed behind an ice shelf that is attached to the coastline. They are mostly found in Antarctica.
The most common type of fluvial lake is a crescent-shaped lake called an oxbow lake due to the distinctive curved shape. They can form in river valleys as a result of meandering. The slow-moving river forms a sinuous shape as the outer side of bends are eroded away more rapidly than the inner side. Eventually a horseshoe bend is formed and the river cuts through the narrow neck. This new passage then forms the main passage for the river and the ends of the bend become silted up, thus forming a bow-shaped lake.
These form where sediment from a tributary blocks the main river.
A solution lake is a lake occupying a basin formed by surface dissolution of bedrock. In areas underlain by soluble bedrock, its solution by precipitation and percolating water commonly produce cavities. These cavities frequently collapse to form sinkholes that form part of the local karst topography. Where groundwater lies near the grounds surface, a sinkhole will be filled water as a solution lake. If such a lake consists of a large area of standing water that occupies an extensive closed depression in limestone, it is also called a karst lake. Smaller solution lakes that consist of a body of standing water in a closed depression within a karst region are known as karst ponds. Limestone caves often contain pools of standing water, which are known as underground lakes. Classic examples of solution lakes are abundant in the karst regions at the Dalmatian coast of Croatia and within large parts of Florida.
Landslide lakes are lakes created by the blockage of a valley by either mudflows, rockslides, or screes. Such lakes are common in mountainous regions. Although landslide lakes may be large and quite deep, they are typically short-lived. An example of a landslide lake is Quake Lake, which formed as a result of the 1959 Hebgen Lake earthquake.
Aeolian lakes are lakes produced by wind action. They are found mainly in arid environments although some aeolian lakes are relict landforms indicative of arid paleoclimates. Aeolian lakes consist of lake basins dammed by wind-blown sand; interdunal lakes that lies between well-oriented sand dunes; and deflation basins formed by wind action under previously arid paleoenvironments. Moses Lake, Washington, is an example of a lake basins dammed by wind-blown sand.
Shoreline lakes are generally lakes created by blockage of estuaries or by the uneven accretion of beach ridges by longshore and other currents. They include maritime coastal lakes, ordinarily in drowned estuaries; lakes enclosed by two tombolos or spits connecting an island to the mainland; lakes cut off from larger lakes by a bar; or lakes divided by the meeting of two spits.
Organic lakes are lakes created by the actions of plants and animals. On the whole they are relatively rare in occurrence and quite small in size. In addition, they typically ephemeral features relative to the other types of lakes. The basins in which organic lakes occur are associated with beaver dams, coral lakes, or dams formed by vegetation.
Peat lakes are a form of organic lake. They form where a buildup of partly decomposed plant material in a wet environment leaves the vegetated surface below the water table for a sustained period of time. They are often low in nutrients and mildly acidic, with bottom waters low in dissolved oxygen.
Anthropogenic lakes are artificially created lakes formed by human activity. They can be the result of intentional damming of rivers and streams or subsequent filling of abandoned excavations by either ground water, precipitation, or a combination of both.
Meteorite lakes, which are also known as crater lakes, are lakes created by catastrophic extraterrestrial impacts by either meteorites or asteroids. Examples of meteorite lakes are Lonar crater lake, India, Lake Elgygytgyn, and Pingualuit crater lake, Quebec, Canada, As in case of Lake El'gygytgyn and Pingualuit crater lake, meteorite (extraterrestrial impact/ crater) lakes can contain unique and scientifically valuable sedimentary deposits associated with long records of paleoclimatic changes.
In addition to mode of origin, lakes have been named and classified in various other ways according to their thermal stratification, salinity, relative seasonal permanence, degree of outflow, and other factors. Also, different cultures and regional of the world have their popular nomenclature
In addition to their origin, there are various other ways of either naming or defining types of lakes. One major way of classification lakes in on the basis of thermal stratification because it is a major control on animal and plant life inhabiting a lake and the fate and distribution of dissolved and suspended material in a lake. For example, the thermal stratification and the degree and frequency of mixing exerts a strong control on the distribution of oxygen within it. In addition, lake can be classified according important factors such as seasonal variations in lake volume and level, oxygen saturation, and salinity of its water mass. Finally, the names of types of lakes that are used by the lay public and in the scientific for different types of lakes are often informally derived from either from their morphology of other aspects or their physical characteristics.
F.A. Forel, who is also referred to as the father of limnology, was the first scientist to classify lakes according to their thermal stratification. His system of classification was later modified and improved upon by Hutchinson and Laffler. Because the density of water varies with temperature, with a maximum at +4 DC, thermal stratification is an important physical characteristic of lakes that controls the fauna and flora, sedimentation, chemistry, and other aspects of individual lakes. First, the colder, heavier water typically forms a layer near the bottom, which called the hypolimnion. Second, normally overlying it is a transition zone known as the metalimnion. Finally, overlying the metalimnion is a surface layer of a warmer, lighter water is called the epilimnion. However, this typical stratification sequence can vary widely depending either on the specific lake, the time of season, or combination of both.
Based upon thermal stratification, lakes are classified as either holomictic lakes or meromictic lakes. A meromictic lake is a lake which has layers of water which do not intermix. The deepest layer of water in such a lake does not contain any dissolved oxygen. In addition, the layers of sediment at the bottom of a meromictic lake remain relatively undisturbed because there are no living aerobic organisms. The lack of disturbance allows for the development of lacustrine varves. A Holomictic lake is a lake that has a uniform temperature and density from top to bottom at a specific time during the year. This uniformity temperature and density in allows the lake waters to completely mix. Holomictic lakes are non-meromictic lakes. Based upon thermal stratification and frequency of turnover, holomictic lakes are divided into amictic lakes, cold monomictic lakes, dimictic lakes, warm monomictic lakes, polymictic lakes, and oligomictic lakes. The classification of lakes by thermal stratification presupposes lakes with sufficient depth to form a hypolimnion. As a results, very shallow lakes are excluded this classification system.
The stratification in a lake is not always the result of variation to density because of thermal gradients. Stratification within a lake can also be the result of differences in density resulting from gradients in salinity. In case of a difference in salinity, the hypolimnion and epilimnion are separated not by a thermocline but by a halocline, which is sometimes referred to as a chemocline.
Lakes are informally classified and named according to the seasonal variation in their lake level and volume. Some of the names include:
Lakes are also informally classified and named according to the general chemistry of their water mass. Some of the types of lakes include:
A paleolake, also spelt palaeolake, is a lake that existed in the past when hydrological conditions were different. Quaternary paleolakes can often be identified on the basis of relict lacustrine landforms such as relict lake plains and coastal landforms that form recognizable relict shorelines, which are called paleoshorelines. Paleolakes can also be recognized by characteristic sedimentary deposits that accumulated in them and any fossils that these sediments might contain. The paleoshorelines and sedimentary deposits of paleolakes provide evidence for prehistoric hydrological changes during the times that they existed.
Types of paleolakes include:
Paleolakes are of scientific and economic importance. For example, Quaternary paleolakes in semidesert basins are important for two reasons. First, they played an extremely significant, if transient, role in shaping the floors and piedmonts of many basins. Finally, their sediments contain enormous quantities of geologic and paleontologic information concerning past environments. In addition, the organic-rich deposits of pre-Quaternary paleolakes are important either for the thick deposits of oil shale and shale gas that they contain or as source rocks of petroleum and natural gas. Although of significantly less economic importance, strata deposited along the shore of paleolakes sometimes contain coal seams.
Lakes have numerous features in addition to lake type, such as drainage basin (also known as catchment area), inflow and outflow, nutrient content, dissolved oxygen, pollutants, pH, and sedimentation.
Changes in the level of a lake are controlled by the difference between the input and output compared to the total volume of the lake. Significant input sources are precipitation onto the lake, runoff carried by streams and channels from the lake's catchment area, groundwater channels and aquifers, and artificial sources from outside the catchment area. Output sources are evaporation from the lake, surface and groundwater flows, and any extraction of lake water by humans. As climate conditions and human water requirements vary, these will create fluctuations in the lake level.
Lakes can be also categorized on the basis of their richness in nutrients, which typically affect plant growth. Nutrient-poor lakes are said to be oligotrophic and are generally clear, having a low concentration of plant life. Mesotrophic lakes have good clarity and an average level of nutrients. Eutrophic lakes are enriched with nutrients, resulting in good plant growth and possible algal blooms. Hypertrophic lakes are bodies of water that have been excessively enriched with nutrients. These lakes typically have poor clarity and are subject to devastating algal blooms. Lakes typically reach this condition due to human activities, such as heavy use of fertilizers in the lake catchment area. Such lakes are of little use to humans and have a poor ecosystem due to decreased dissolved oxygen.
Due to the unusual relationship between water's temperature and its density, lakes form layers called thermoclines, layers of drastically varying temperature relative to depth. Fresh water is most dense at about 4 degrees Celsius (39.2 °F) at sea level. When the temperature of the water at the surface of a lake reaches the same temperature as deeper water, as it does during the cooler months in temperate climates, the water in the lake can mix, bringing oxygen-starved water up from the depths and bringing oxygen down to decomposing sediments. Deep temperate lakes can maintain a reservoir of cold water year-round, which allows some cities to tap that reservoir for deep lake water cooling.
Since the surface water of deep tropical lakes never reaches the temperature of maximum density, there is no process that makes the water mix. The deeper layer becomes oxygen starved and can become saturated with carbon dioxide, or other gases such as sulfur dioxide if there is even a trace of volcanic activity. Exceptional events, such as earthquakes or landslides, can cause mixing which rapidly brings the deep layers up to the surface and release a vast cloud of gas which lay trapped in solution in the colder water at the bottom of the lake. This is called a limnic eruption. An example is the disaster at Lake Nyos in Cameroon. The amount of gas that can be dissolved in water is directly related to pressure. As deep water surfaces, the pressure drops and a vast amount of gas comes out of solution. Under these circumstances carbon dioxide is hazardous because it is heavier than air and displaces it, so it may flow down a river valley to human settlements and cause mass asphyxiation.
The material at the bottom of a lake, or lake bed, may be composed of a wide variety of inorganics, such as silt or sand, and organic material, such as decaying plant or animal matter. The composition of the lake bed has a significant impact on the flora and fauna found within the lake's environs by contributing to the amounts and the types of nutrients available.
A paired (black and white) layer of the varved lake sediments correspond to a year. During winter, when organisms die, carbon is deposited down, resulting to a black layer. At the same year, during summer, only few organic materials are deposited, resulting to a white layer at the lake bed. These are commonly used to track past paleontological events.
Natural lakes provide a microcosm of living and nonliving elements that are relatively independent of their surrounding environments. Therefore, lake organisms can often be studied in isolation from the lake’s surroundings.
Limnology is the study of inland bodies of water and related ecosystems. Limnology divides lakes into three zones: the littoral zone, a sloped area close to land; the photic or open-water zone, where sunlight is abundant; and the deep-water profundal or benthic zone, where little sunlight can reach. The depth to which light can reach in lakes depends on turbidity, determined by the density and size of suspended particles. A particle is in suspension if its weight is less than the random turbidity forces acting upon it. These particles can be sedimentary or biological in origin and are responsible for the color of the water. Decaying plant matter, for instance, may be responsible for a yellow or brown color, while algae may cause greenish water. In very shallow water bodies, iron oxides make water reddish brown. Biological particles include algae and detritus. Bottom-dwelling detritivorous fish can be responsible for turbid waters, because they stir the mud in search of food. Piscivorous fish contribute to turbidity by eating plant-eating (planktonivorous) fish, thus increasing the amount of algae (see aquatic trophic cascade). The light depth or transparency is measured by using a Secchi disk, a 20-cm (8 in) disk with alternating white and black quadrants. The depth at which the disk is no longer visible is the Secchi depth, a measure of transparency. The Secchi disk is commonly used to test for eutrophication. For a detailed look at these processes, see lentic ecosystems.
A lake moderates the surrounding region's temperature and climate because water has a very high specific heat capacity (4,186 J·kg−1·K−1). In the daytime a lake can cool the land beside it with local winds, resulting in a sea breeze; in the night it can warm it with a land breeze.
The lake may be infilled with deposited sediment and gradually become a wetland such as a swamp or marsh. Large water plants, typically reeds, accelerate this closing process significantly because they partially decompose to form peat soils that fill the shallows. Conversely, peat soils in a marsh can naturally burn and reverse this process to recreate a shallow lake resulting in a dynamic equilibrium between marsh and lake. This is significant since wildfire has been largely suppressed in the developed world over the past century. This has artificially converted many shallow lakes into emergent marshes. Turbid lakes and lakes with many plant-eating fish tend to disappear more slowly. A "disappearing" lake (barely noticeable on a human timescale) typically has extensive plant mats at the water's edge. These become a new habitat for other plants, like peat moss when conditions are right, and animals, many of which are very rare (example?). Gradually the lake closes and young peat may form, forming a fen. In lowland river valleys where a river can meander, the presence of peat is explained by the infilling of historical oxbow lakes. In the very last stages of succession, trees can grow in, eventually turning the wetland into a forest.
Some lakes can disappear seasonally. These are called intermittent lakes, ephemeral lakes, or seasonal lakes and can be found in karstic terrain. A prime example of an intermittent lake is Lake Cerknica in Slovenia or Lag Prau Pulte in Graubünden. Other intermittent lakes are only the result of above-average precipitation in a closed, or endorheic basin, usually filling dry lake beds. This can occur in some of the driest places on earth, like Death Valley. This occurred in the spring of 2005, after unusually heavy rains. The lake did not last into the summer, and was quickly evaporated (see photos to right). A more commonly filled lake of this type is Sevier Lake of west-central Utah.
Sometimes a lake will disappear quickly. On 3 June 2005, in Nizhny Novgorod Oblast, Russia, a lake called Lake Beloye vanished in a matter of minutes. News sources reported that government officials theorized that this strange phenomenon may have been caused by a shift in the soil underneath the lake that allowed its water to drain through channels leading to the Oka River.
The presence of ground permafrost is important to the persistence of some lakes. According to research published in the journal Science ("Disappearing Arctic Lakes", June 2005), thawing permafrost may explain the shrinking or disappearance of hundreds of large Arctic lakes across western Siberia. The idea here is that rising air and soil temperatures thaw permafrost, allowing the lakes to drain away into the ground.
Some lakes disappear because of human development factors. The shrinking Aral Sea is described as being "murdered" by the diversion for irrigation of the rivers feeding it.
Only one world other than Earth is known to harbor large lakes, Saturn's largest moon, Titan. Photographs and spectroscopic analysis by the Cassini–Huygens spacecraft show liquid ethane on the surface, which is thought to be mixed with liquid methane. The largest Titanean lake, Kraken Mare at 400,000 km2, is three-times the size of any lake on Earth, and even the second, Ligeia Mare, is estimated to be slightly larger than Earth's Lake Michigan–Huron.
Jupiter's large moon Io is volcanically active, and as a result sulfur deposits have accumulated on the surface. Some photographs taken during the Galileo mission appear to show lakes of liquid sulfur in volcanic caldera, though these are more analogous to lake of lava than of water on Earth.
The planet Mars has only one confirmed lake; it is underground and near the south pole. However, the surface of Mars is too cold and has too little atmospheric pressure to permit permanent surface water. Geologic evidence appears to confirm, however, that ancient lakes once formed on the surface. It is also possible that volcanic activity on Mars will occasionally melt subsurface ice, creating large temporary lakes. This water would quickly freeze and then sublimate, unless insulated in some manner, such as by a coating of volcanic ash.
There are dark basaltic plains on the Moon, similar to lunar maria but smaller, that are called lacus (singular lacus, Latin for "lake") because they were thought by early astronomers to be lakes of water.
The largest lakes (surface area) by continent are:
The United States Air Force facility commonly known as Area 51 is a highly classified remote detachment of Edwards Air Force Base, within the Nevada Test and Training Range. According to the Central Intelligence Agency (CIA), the correct names for the facility are Homey Airport (ICAO: KXTA) and Groom Lake, though the name Area 51 was used in a CIA document from the Vietnam War. The facility has also been referred to as Dreamland and Paradise Ranch, among other nicknames. USAF public relations has referred to the facility as "an operating location near Groom Dry Lake". The special use airspace around the field is referred to as Restricted Area 4808 North (R-4808N).The base's current primary purpose is publicly unknown; however, based on historical evidence, it most likely supports the development and testing of experimental aircraft and weapons systems (black projects). The intense secrecy surrounding the base has made it the frequent subject of conspiracy theories and a central component to unidentified flying object (UFO) folklore. Although the base has never been declared a secret base, all research and occurrences in Area 51 are Top Secret/Sensitive Compartmented Information (TS/SCI). On 25 June 2013, following a Freedom of Information Act (FOIA) request filed in 2005, the CIA publicly acknowledged the existence of the base for the first time, declassifying documents detailing the history and purpose of Area 51.Area 51 is located in the southern portion of Nevada in the western United States, 83 miles (134 km) north-northwest of Las Vegas. Situated at its center, on the southern shore of Groom Lake, is a large military airfield. The site was acquired by the United States Air Force in 1955, primarily for the flight testing of the Lockheed U-2 aircraft. The area around Area 51, including the small town of Rachel on the "Extraterrestrial Highway", is a popular tourist destination.Dead Sea
The Dead Sea (Hebrew: יָם הַמֶּלַח Yam ha-Melah lit. Sea of Salt; Arabic: البحر الميت Al-Bahr al-Mayyit) is a salt lake bordered by Jordan to the east and Israel and the West Bank to the west. It lies in the Jordan Rift Valley, and its main tributary is the Jordan River.
Its surface and shores are 430.5 metres (1,412 ft) below sea level, Earth's lowest elevation on land. It is 304 m (997 ft) deep, the deepest hypersaline lake in the world. With a salinity of 342 g/kg, or 34.2% (in 2011), it is one of the world's saltiest bodies of water – 9.6 times as salty as the ocean – and has a density of 1.24 kg/litre, which makes swimming similar to floating. This salinity makes for a harsh environment in which plants and animals cannot flourish, hence its name. The Dead Sea's main, northern basin is 50 kilometres (31 mi) long and 15 kilometres (9 mi) wide at its widest point.The Dead Sea has attracted visitors from around the Mediterranean Basin for thousands of years. It was one of the world's first health resorts (for Herod the Great), and it has been the supplier of a wide variety of products, from asphalt for Egyptian mummification to potash for fertilisers.
The Dead Sea is receding at a swift rate; its surface area today is 605 km2 (234 sq mi), having been 1,050 km2 (410 sq mi) in 1930. The recession of the Dead Sea has begun causing problems, and multiple canals and pipelines proposals exist to reduce its recession. One of these proposals is the Red Sea–Dead Sea Water Conveyance project, carried out by Jordan, which will provide water to neighbouring countries, while the brine will be carried to the Dead Sea to help stabilise its water level. The first phase of the project is scheduled to begin in 2018 and be completed in 2021.Endorheic basin
An endorheic basin (also endoreic basin or endorreic basin) is a limited drainage basin that normally retains water and allows no outflow to other external bodies of water, such as rivers or oceans, but converges instead into lakes or swamps, permanent or seasonal, that equilibrate through evaporation. Such a basin may also be referred to as a closed or terminal basin or as an internal drainage system or interior drainage basin.
Endorheic regions, in contrast to exorheic regions, which flow to the ocean in geologically defined patterns, are closed hydrologic systems. Their surface waters drain to inland terminal locations where the water evaporates or seeps into the ground, having no access to discharge into the sea. Endorheic water bodies include some of the largest lakes in the world, such as the Caspian Sea, the world's largest saline inland sea.Endorheic basins constitute local base levels, defining a limit of erosion and deposition processes of nearby areas.The term comes from the Ancient Greek: ἔνδον, éndon, "within" and ῥεῖν, rheîn, "to flow".Fjord
Geologically, a fjord or fiord ( (listen), (listen)) is a long, narrow inlet with steep sides or cliffs, created by a glacier. There are many fjords on the coasts of Alaska, Antarctica, British Columbia, Chile, Greenland, the Faroe Islands, Iceland, Kamchatka, the Kerguelen Islands, New Zealand, Norway, Novaya Zemlya, Labrador, Nunavut, Newfoundland, Quebec, Scotland, South Georgia Island, and Washington state. Norway's coastline is estimated at 29,000 kilometres (18,000 mi) with nearly 1,200 fjords, but only 2,500 kilometres (1,600 mi) when fjords are excluded.Great Lakes
The Great Lakes (French: les Grands-Lacs), also called the Laurentian Great Lakes and the Great Lakes of North America, are a series of interconnected freshwater lakes primarily in the upper mid-east region of North America, on the Canada–United States border, which connect to the Atlantic Ocean through the Saint Lawrence River. They consist of Lakes Superior, Michigan, Huron, Erie, and Ontario. Hydrologically, there are only four lakes, because Lakes Michigan and Huron join at the Straits of Mackinac. The lakes form the Great Lakes Waterway.
The Great Lakes are the largest group of freshwater lakes on Earth by total area, and second-largest by total volume, containing 21% of the world's surface fresh water by volume. The total surface is 94,250 square miles (244,106 km2), and the total volume (measured at the low water datum) is 5,439 cubic miles (22,671 km3), slightly less than the volume of Lake Baikal (5,666 cu mi or 23,615 km3, 22–23% of the world's surface fresh water). Due to their sea-like characteristics (rolling waves, sustained winds, strong currents, great depths, and distant horizons) the five Great Lakes have also long been referred to as inland seas. Lake Superior is the second largest lake in the world by area, and the largest freshwater lake by area. Lake Michigan is the largest lake that is entirely within one country.The Great Lakes began to form at the end of the last glacial period around 14,000 years ago, as retreating ice sheets exposed the basins they had carved into the land which then filled with meltwater. The lakes have been a major source for transportation, migration, trade, and fishing, serving as a habitat to a large number of aquatic species in a region with much biodiversity.
The surrounding region is called the Great Lakes region, which includes the Great Lakes Megalopolis.Lake Baikal
Lake Baikal (; Russian: о́зеро Байка́л, tr. Ozero Baykal, IPA: [ˈozʲɪrə bɐjˈkaɫ]; Buryat: Байгал нуур, Baigal nuur; Mongolian: Байгал нуур, Baigal nuur, etymologically meaning, in Mongolian, "the Nature Lake") is a rift lake in Russia, located in southern Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast.
Lake Baikal is the largest freshwater lake by volume in the world, containing 22–23% of the world's fresh surface water. With 23,615.39 km3 (5,670 cu mi) of fresh water, it contains more water than the North American Great Lakes combined. With a maximum depth of 1,642 m (5,387 ft), Baikal is the world's deepest lake. It is considered among the world's clearest lakes and is considered the world's oldest lake – at 25–30 million years. It is the seventh-largest lake in the world by surface area.
Like Lake Tanganyika, Lake Baikal was formed as an ancient rift valley, having the typical long, crescent shape with a surface area of 31,722 km2 (12,248 sq mi). Baikal is home to thousands of species of plants and animals, many of which exist nowhere else in the world. The lake was declared a UNESCO World Heritage Site in 1996. It is also home to Buryat tribes who reside on the eastern side of Lake Baikal, raising goats, camels, cattle, sheep, and horses, where the mean temperature varies from a winter minimum of −19 °C (−2 °F) to a summer maximum of 14 °C (57 °F).The region to the east of Lake Baikal is referred to as Transbaikalia, and the loosely defined region around the lake is sometimes known as simply Baikalia.Lake District
The Lake District, also known as the Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous for its lakes, forests and mountains (or fells), and its associations with William Wordsworth and other Lake Poets and also with Beatrix Potter and John Ruskin. The National Park was established in 1951 and covers an area of 2,362 square kilometres. It was designated a UNESCO World Heritage Site in 2017.The Lake District is located entirely within the county of Cumbria. All the land in England higher than 3,000 feet (914 m) above sea level lies within the National Park, including Scafell Pike, the highest mountain in England. It also contains the deepest and largest natural lakes in England, Wast Water and Windermere respectively.Lake Erie
Lake Erie (; French: Lac Érié) is the fourth-largest lake (by surface area) of the five Great Lakes in North America, and the eleventh-largest globally if measured in terms of surface area. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. At its deepest point Lake Erie is 210 feet (64 metres) deep.
Situated on the International Boundary between Canada and the United States, Lake Erie's northern shore is the Canadian province of Ontario, specifically the Ontario Peninsula, with the U.S. states of Michigan, Ohio, Pennsylvania, and New York on its western, southern, and eastern shores. These jurisdictions divide the surface area of the lake with water boundaries.
The lake was named by the Erie people, a Native American people who lived along its southern shore. The tribal name "erie" is a shortened form of the Iroquoian word erielhonan, meaning "long tail".Situated below Lake Huron, Erie's primary inlet is the Detroit River. The main natural outflow from the lake is via the Niagara River, which provides hydroelectric power to Canada and the U.S. as it spins huge turbines near Niagara Falls at Lewiston, New York and Queenston, Ontario. Some outflow occurs via the Welland Canal, part of the St. Lawrence Seaway, which diverts water for ship passages from Port Colborne, Ontario on Lake Erie, to St. Catharines on Lake Ontario, an elevation difference of 326 ft (99 m). Lake Erie's environmental health has been an ongoing concern for decades, with issues such as overfishing, pollution, algae blooms, and eutrophication generating headlines.Lake Michigan
Lake Michigan is one of the five Great Lakes of North America and the only one located entirely within the United States. The other four Great Lakes are shared by the U.S. and Canada. It is the second-largest of the Great Lakes by volume (1,180 cu mi (4,900 km3)) and the third-largest by surface area (22,404 sq mi (58,030 km2)), after Lake Superior and Lake Huron (and is slightly smaller than the U.S. state of West Virginia). To the east, its basin is conjoined with that of Lake Huron through the wide Straits of Mackinac, giving it the same surface elevation as its easterly counterpart; the two are technically a single lake.Lake Michigan is shared, from west to east, by the U.S. states of Wisconsin, Illinois, Indiana, and Michigan. Ports along its shores include Chicago; Milwaukee; Green Bay, Wisconsin; Gary, Indiana; and Muskegon, Michigan. The word "Michigan" originally referred to the lake itself, and is believed to come from the Ojibwe word michi-gami meaning "great water".Lake Superior
Lake Superior (French: lac Supérieur; Ojibwe: ᑭᑦᒉᐁ-ᑲᒣᐁ, romanized: Gitchi-Gami), the largest of the Great Lakes of North America, is also the world's largest freshwater lake by surface area, and the third largest freshwater lake by volume. The lake is shared by the Canadian province of Ontario to the north, the U.S. state of Minnesota to the west, and Wisconsin and the Upper Peninsula of Michigan to the south. The farthest north and west of the Great Lakes chain, Superior has the highest elevation of all five great lakes and drains into the St. Mary's River.Lake Tahoe
Lake Tahoe (; Washo: dáʔaw or Da ow, 'the lake') is a large freshwater lake in the Sierra Nevada of the United States. Lying at 6,225 ft (1,897 m), it straddles the state line between California and Nevada, west of Carson City. Lake Tahoe is the largest alpine lake in North America, and at 122,160,280 acre⋅ft (150.7 km3) trails only the five Great Lakes as the largest by volume in the United States. Its depth is 1,645 ft (501 m), making it the second deepest in the United States after Crater Lake in Oregon (1,949 ft or 594 m).The lake was formed about two million years ago as part of the Lake Tahoe Basin, with the modern extent being shaped during the ice ages. It is known for the clarity of its water and the panorama of surrounding mountains on all sides. The area surrounding the lake is also referred to as Lake Tahoe, or simply Tahoe. More than 75% of the lake's watershed is national forest land, comprising the Lake Tahoe Basin Management Unit of the United States Forest Service.
Lake Tahoe is a major tourist attraction in both Nevada and California. It is home to winter sports, summer outdoor recreation, and scenery enjoyed throughout the year. Snow and ski resorts are a significant part of the area's economy and reputation. The Nevada side also offers several lakeside casino resorts, with highways providing year-round access to the entire area.Lake Victoria
Lake Victoria (Nam Lolwe in Luo; Nalubaale in Uganda; Nyanza in some Bantu languages) is one of the African Great Lakes.
The lake was renamed Lake Victoria after Queen Victoria by the explorer John Hanning Speke, in his reports—the first Briton to document it. (It has since been recognized that the native guides used the name Lake Nyanza to describe it to him.) Speke accomplished this in 1858, while on an expedition with Richard Francis Burton to locate the source of the Nile River. This expedition was financially sponsored by the Royal Geographic Society, an imperial organization that, upon notifying this news to the queen, received a royal charter. It is not clear if this was in appreciation of the lake renaming.
With a surface area of approximately 59,947 square kilometres (23,146 sq mi), Lake Victoria is Africa's largest lake by area, the world's largest tropical lake, and the world's second largest fresh water lake by surface area after Lake Superior in North America. In terms of volume, Lake Victoria is the world's ninth largest continental lake, containing about 2,424 cubic kilometres (1.965×109 acre⋅ft) of water.Lake Victoria occupies a shallow depression in Africa. The lake has a maximum depth of between 80 and 84 metres (262 and 276 ft) and an average depth of 40 metres (130 ft). Its catchment area covers 169,858 square kilometres (65,583 sq mi). The lake has a shoreline of 7,142 kilometres (4,438 mi) when digitized at the 1:25,000 level, with islands constituting 3.7 percent of this length, and is divided among three countries: Kenya (6 percent or 4,100 square kilometres or 1,600 square miles), Uganda (45 percent or 31,000 square kilometres or 12,000 square miles), and Tanzania (49 percent or 33,700 square kilometres or 13,000 square miles).Reservoir
A reservoir (from French réservoir – a "tank") is, most commonly, an enlarged natural or artificial lake, pond or impoundment created using a dam or lock to store water.
Reservoirs can be created in a number of ways, including controlling a watercourse that drains an existing body of water, interrupting a watercourse to form an embayment within it, through excavation, or building any number of retaining walls or levees.
Defined as a storage space for fluids, reservoirs may hold water or gasses, including hydrocarbons. Tank reservoirs store these in ground-level, elevated, or buried tanks. Tank reservoirs for water are also called cisterns. Most underground reservoirs are used to store liquids, principally either water or petroleum, below ground.Salt Lake City
Salt Lake City (often shortened to Salt Lake and abbreviated as SLC) is the capital and most populous municipality of the U.S. state of Utah, and county seat of Salt Lake County. With an estimated population of 190,884 in 2014, the city is the core of the Salt Lake City metropolitan area, which has a population of 1,153,340 (2014 estimate). Salt Lake City is further situated within a larger metropolis known as the Salt Lake City–Ogden–Provo Combined Statistical Area, a corridor of contiguous urban and suburban development stretched along a 120-mile (190 km) segment of the Wasatch Front, comprising a population of 2,423,912 (as of 2014 estimates). It is one of only two major urban areas in the Great Basin.The world headquarters of The Church of Jesus Christ of Latter-day Saints (LDS Church) is located in Salt Lake City. The city was founded in 1847 by followers of the church, led by Brigham Young, who were seeking to escape persecution that they had experienced while living farther east. The Mormon pioneers, as they would come to be known, at first encountered an arid, inhospitable valley that they then extensively irrigated and cultivated, thereby establishing the foundation to sustain the area's present population. Salt Lake City's street grid system is based on the north-south east-west grid plan developed by early church leaders, with the Salt Lake Temple constructed at the grid's starting point.
Due to its proximity to the Great Salt Lake, the city was named Great Salt Lake City. In 1868, the 17th Utah Territorial Legislature dropped the word "Great" from the city's name.Immigration of international members of the church, mining booms, and the construction of the first transcontinental railroad initially brought economic growth, and the city was nicknamed the Crossroads of the West. It was traversed by the Lincoln Highway, the first transcontinental highway, in 1913. Two major cross-country freeways, I-15 and I-80, now intersect in the city. Salt Lake City has developed a strong outdoor recreation tourist industry based primarily on skiing, and the city hosted the 2002 Winter Olympics. It is the industrial banking center of the United States.Sea of Galilee
The Sea of Galilee (Hebrew: יָם כִּנֶּרֶת, Judeo-Aramaic: יַמּא דטבריא, גִּנֵּיסַר, Arabic: بحيرة طبريا), Lake Tiberias, Kinneret or Kinnereth, is a freshwater lake in Israel. It is the lowest freshwater lake on Earth and the second-lowest lake in the world (after the Dead Sea, a saltwater lake), at levels between 215 metres (705 ft) and 209 metres (686 ft) below sea level. It is approximately 53 km (33 mi) in circumference, about 21 km (13 mi) long, and 13 km (8.1 mi) wide. Its area is 166.7 km2 (64.4 sq mi) at its fullest, and its maximum depth is approximately 43 m (141 feet). The lake is fed partly by underground springs, although its main source is the Jordan River, which flows through it from north to south.Utah
Utah ( YOO-tah, (listen) YOO-taw) is a state in the western United States. It became the 45th state admitted to the U.S. on January 4, 1896. Utah is the 13th-largest by area, 30th-most-populous, and 11th-least-densely populated of the 50 United States. Utah has a population of more than 3 million according to the Census estimate for July 1, 2016. Urban development is mostly concentrated in two areas: the Wasatch Front in the north-central part of the state, which contains approximately 2.5 million people; and Washington County in Southern Utah, with over 160,000 residents. Utah is bordered by Colorado to the east, Wyoming to the northeast, Idaho to the north, Arizona to the south, and Nevada to the west. It also touches a corner of New Mexico in the southeast.
Approximately 62% of Utahns are reported to be members of The Church of Jesus Christ of Latter-day Saints (LDS Church), making Utah the only state with a majority population belonging to a single church. This greatly influences Utahn culture and daily life. The LDS Church's world headquarters is located in Salt Lake City.The state is a center of transportation, education, information technology and research, government services, mining, and a major tourist destination for outdoor recreation. In 2013, the U.S. Census Bureau estimated that Utah had the second fastest-growing population of any state. St. George was the fastest-growing metropolitan area in the United States from 2000 to 2005. Utah also has the 14th highest median average income and the least income inequality of any U.S. state. A 2012 Gallup national survey found Utah overall to be the "best state to live in" based on 13 forward-looking measurements including various economic, lifestyle, and health-related outlook metrics.Yellowstone National Park
Yellowstone National Park is an American national park located in Wyoming, Montana, and Idaho. It was established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the U.S. and is also widely held to be the first national park in the world. The park is known for its wildlife and its many geothermal features, especially Old Faithful geyser, one of its most popular features. It has many types of ecosystems, but the subalpine forest is the most abundant. It is part of the South Central Rockies forests ecoregion.
Native Americans have lived in the Yellowstone region for at least 11,000 years. Aside from visits by mountain men during the early-to-mid-19th century, organized exploration did not begin until the late 1860s. Management and control of the park originally fell under the jurisdiction of the Secretary of the Interior, the first being Columbus Delano. However, the U.S. Army was subsequently commissioned to oversee management of Yellowstone for a 30-year period between 1886 and 1916. In 1917, administration of the park was transferred to the National Park Service, which had been created the previous year. Hundreds of structures have been built and are protected for their architectural and historical significance, and researchers have examined more than a thousand archaeological sites.
Yellowstone National Park spans an area of 3,468.4 square miles (8,983 km2), comprising lakes, canyons, rivers and mountain ranges. Yellowstone Lake is one of the largest high-elevation lakes in North America and is centered over the Yellowstone Caldera, the largest supervolcano on the continent. The caldera is considered an active volcano. It has erupted with tremendous force several times in the last two million years. Half of the world's geysers and hydrothermal features are in Yellowstone, fueled by this ongoing volcanism. Lava flows and rocks from volcanic eruptions cover most of the land area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining nearly-intact ecosystem in the Earth's northern temperate zone. In 1978, Yellowstone was named a UNESCO World Heritage Site.
Hundreds of species of mammals, birds, fish, and reptiles have been documented, including several that are either endangered or threatened. The vast forests and grasslands also include unique species of plants. Yellowstone Park is the largest and most famous megafauna location in the contiguous United States. Grizzly bears, wolves, and free-ranging herds of bison and elk live in this park. The Yellowstone Park bison herd is the oldest and largest public bison herd in the United States. Forest fires occur in the park each year; in the large forest fires of 1988, nearly one third of the park was burnt. Yellowstone has numerous recreational opportunities, including hiking, camping, boating, fishing and sightseeing. Paved roads provide close access to the major geothermal areas as well as some of the lakes and waterfalls. During the winter, visitors often access the park by way of guided tours that use either snow coaches or snowmobiles.