Lakes


A lake is a body of relatively still water of considerable size, localized in a basin, that is surrounded by land apart from a river, stream, or other form of moving water that serves to feed or drain the lake. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds Lakes can be contrasted with rivers or streams, which are usually flowing. However 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 or recreational purposes.




Pseudoscience: Extraterrestrials Lakes

In creation myths and pseudoscience, lakes are sometimes referenced as the place the gods descended to - or emerged from - to create humanity. There is always the message that these gods will return one day.

Dogon Mythology - The Nommo


Amphibious Gods


Many believe there are subterranean alien bases under lakes and oceans. UFO's are seen rising form the water by locals in places such as Lake Titicaca, where legends of ancient astronauts who visited the planet thousands of years ago, are common. USOs - Unidentified Submerged Objects




In the News ...





Massive 'lake' discovered under volcano could unlock why and how volcanoes erupt   Science Daily - November 8, 2016

A huge magmatic lake has been discovered, 15 kilometers below a dormant volcano in Bolivia, South America. The body of water, which is dissolved into partially molten rock at a temperature of almost 1,000 degrees Celsius, is the equivalent to what is found in some of the world's giant freshwater lakes, such as Lake Superior. The find has now led scientists to consider if similar bodies of water may be 'hiding' under other volcanoes and could help explain why and how volcanoes erupt.




Ancient lake challenges understanding of evolution   PhysOrg - May 20, 2015

Scientists have studied samples of lake sediments deposited 1.5 billion years ago in the Bay of Stoer region in north-west Scotland, and discovered high levels of the metal molybdenum, a key element in the evolution of multicellular life. The discovery challenges the commonly held view that an important stage of evolution, leading eventually to human life, occurred in the deep ocean, as opposed to a continental environment.




'Crazy Craters' Found in Swiss Lake   Live Science - May 20, 2015

Four giant craters were found by accident in the muddy floor of one of Switzerland's largest lakes, a new study reports. Researchers surveying Lake Neuchatel for evidence of past earthquakes spotted the craters near the lake's northwestern shore near the Jura Mountains. The biggest crater is 525 feet (160 meters) wide and almost 100 feet (30 m) deep. The pits are among the largest and deepest pockmarks ever found in Earth's lakes, the researchers said. The giant craters are similar in size to seafloor pockmarks created by methane-gas explosions. However, the researchers think that erupting groundwater excavated these "crazy craters."




Scientists uncover "God's bathtub"   Yahoo - June 5, 2013

Blue Lake Imagine a lake that's never been affected by climate change or any other man-made influences. Australian scientists say they have found just that - a remote lake whose crystal-clear waters seem to be in the same chemical state as they were about 7,500 years ago. Several other nearby former lakes have dried up over the past 40 years due to climate change.




Types of Lakes

Periglacial: Part of the lake's margin is formed by an ice sheet, ice cap, or glacier, the ice having obstructed the natural drainage of the land.

Subglacial: A lake which is permanently covered by ice. They can occur under glaciers, ice caps, or ice sheets. There are many such lakes, but Lake Vostok in Antarctica is by far the largest. They are kept liquid because the overlying ice acts as a thermal insulator retaining energy introduced to its underside by friction, by water percolating through crevasses, by the pressure from the mass of the ice sheet above, or by geothermal heating below.

Glacial lake: a lake with origins in a melted glacier.

Artificial: A lake created by flooding land behind a dam, called an impoundment or reservoir; by deliberate human excavation; or by the flooding of an excavation incident to a mineral-extraction operation such as an open pit mine or quarry. Some of the world's largest lakes are reservoirs.

Endorheic, also called terminal or closed: A lake which has no significant outflow, either through rivers or underground diffusion. Any water within an endorheic basin leaves the system only through evaporation or seepage. These lakes, such as Lake Eyre in central Australia or the Aral Sea in central Asia, are most common in desert locations.

Meromictic: 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. The layers of sediment at the bottom of a meromictic lake remain relatively undisturbed because there are no living aerobic organisms.

Fjord lake: A lake in a glacially eroded valley that has been eroded below sea level.

Oxbow: A lake which is formed when a wide meander from a stream or a river is cut off to form a lake. They are called "oxbow" lakes due to the distinctive curved shape that results from this process.

Rift lake: A lake which forms as a result of subsidence along a geological fault in the Earth's tectonic plates. Examples include the Rift Valley lakes of eastern Africa and Lake Baikal in Siberia.

Underground: A lake which is formed under the surface of the Earth's crust. Such a lake may be associated with caves, aquifers, or spring

Crater: A lake which forms in a volcanic caldera or crater after the volcano has been inactive for some time. Water in this type of lake may be fresh or highly acidic and may contain various dissolved minerals. Some also have geothermal activity, especially if the volcano is merely dormant rather than extinct.

Lava: A pool of molten lava contained in a volcanic crater or other depression. Lava lakes that have partly or completely solidified are also referred to as lava lakes.

Former: A lake which is no longer in existence. Such lakes include prehistoric lakes and lakes which have permanently dried up through evaporation or human intervention. Owens Lake in California, USA, is an example of a former lake. Former lakes are a common feature of the Basin and Range area of southwestern North America.

Seasonal lake: A lake that exists as a body of water during only part of the year.

Shrunken: Closely related to former lakes, a shrunken lake is one which has drastically decreased in size over geological time. Lake Agassiz, which once covered much of central North America, is a good example of a shrunken lake. Two notable remnants of this lake are Lake Winnipeg and Lake Winnipegosis.

Eolic: A lake which forms in a depression created by the activity of the winds.




How Lakes Disappear

A 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.

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. 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 and are typically found in karstic terrain. A prime example of an intermittent lake is Lake Cerknica in Slovenia. 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.

Neusiedler See, located in Austria and Hungary, has dried up many times over the millennia. As of 2005, it is again rapidly losing water, giving rise to the fear that it will be completely dry by 2010.

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.


Lake disappears suddenly in Chile BBC - June 22, 2007
Scientists in Chile are investigating the sudden disappearance of a glacial lake in the south of the country. When park rangers patrolled the area in the Magallanes region in March, the two-hectare (five-acre) lake was its normal size, officials say. But last month they found a huge dry crater and several stranded chunks of ice that used to float on the water. One theory is that an earthquake opened up a fissure in the ground, allowing the lake's water to drain through.




Great Lakes


The Great Lakes (sometimes, Laurentian Great Lakes) are a collection of freshwater lakes located in northeastern North America, on the CanadaŠUnited States border, which connect to the Atlantic Ocean through the Saint Lawrence Seaway and the Great Lakes Waterway. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth, containing 21% of the world's surface fresh water. ,p> 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). The lakes are sometimes referred to as the North Coast or "Third Coast" by some citizens of the United States. They have also been referred to as North America's fourth coast, as traversing the shoreline of each of the lakes covers about 17,000 km (11,000 mi) roughly the distance of almost half the Earth's equator.

The Great Lakes began to form at the end of the last glacial period around 10,000 years ago, as retreating ice sheets carved basins into the land and they became filled with meltwater. The lakes have been a major source of trade through their region, and are home to a large number of aquatic species. Many invasive species have been introduced due to trade in the area, and some threaten the region's biodiversity. Read more ...


Great Lake's sinkholes host exotic ecosystems   PhysOrg - February 25, 2009

As little as 20 meters (66 feet) below the surface of Lake Huron, the third largest of North America's Great Lakes, peculiar geological formations - sinkholes made by water dissolving parts of an ancient underlying seabed - harbor bizarre ecosystems where the fish typical of the huge freshwater lake are rarely to be seen. Instead, brilliant purple mats of cyanobacteria - cousins of microbes found at the bottoms of permanently ice-covered lakes in Antarctica - and pallid, floating pony-tails of other microbial life thrive in the dense, salty water that's hostile to most familiar, larger forms of life because it lacks oxygen.


Odd Life Found in Great Lakes   Live Science - February 25, 2009

Scientists have found some odd life forms in Lake Huron. Peculiar geological formations are supporting floating plumes and purple mats of microbes dwelling in enclaves of the Great Lake, researchers report. The odd biology is more akin to what is found in some of Earth's most extreme environments. The mats are located about 66 feet (20 meters) below the surface of Lake Huron - the third largest of North America's Great Lakes where researchers have found sinkholes made by water dissolving parts of an ancient underlying seabed.


Shrinking Lake Superior Also Heating Up   National Geographic - August 3, 2007
Lake Superior, the world's largest freshwater lake, has been shrinking for years - and now it appears to be getting hotter. Beachgoers at the lake, which is bounded by Wisconsin, Michigan, Minnesota, and Ontario, Canada, must walk up to 300 feet (100 yards) farther to reach shorelines. Some docks are unusable because of low water, and once-submerged lake edges now grow tangles of tall wetland plants. The remaining lake water is also heating up at dramatic rates. Such changes are sparking implausible conspiracy theories about the water's fate, along with new scientific investigations. Researchers are also starting to suspect that the shrinking and heating are related - and that both are spurred by rising global temperatures and a sustained local drought.




Antarctica


Lake Vostok is the largest of Antarctica's almost 400 known subglacial lakes. Lake Vostok is located at the southern Pole of Cold, beneath Russia's Vostok Station under the surface of the central East Antarctic Ice Sheet, which is at 3,488 m (11,444 ft) above mean sea level. The surface of this fresh water lake is approximately 4,000 m (13,100 ft) under the surface of the ice, which places it at approximately 500 m (1,600 ft) below sea level. Measuring 250 km (160 mi) long by 50 km (30 mi) wide at its widest point, and covering an area of 12,500 km2 (4,830 sq mi) and an average depth of 432 m (1,417 ft), it has an estimated volume of 5,400 km3 (1,300 cu mi). The lake is divided into two deep basins by a ridge. The liquid water over the ridge is about 200 m (700 ft), compared to roughly 400 m (1,300 ft) deep in the northern basin and 800 m (2,600 ft) deep in the southern. Read more ...


Confirmed: There's life in buried Antarctic lake   MSNBC - February 13, 2013
Blobs and smears of microbial life growing in clear plastic disks are confirmation of a community living in a lake buried beneath the Antarctic ice, scientists studying the lake have said. Water retrieved from subglacial Lake Whillans contains about 1,000 bacteria per milliliter (about a fifth of a teaspoon) of lake water. Petri dishes swiped with samples of the lake water are already growing colonies of microbes at a good rate


The lake that time forgot   Telegraph.co.uk - May 30, 2012

After 20 million years below the Antarctic ice, Lake Vostok will finally reveal its secrets At the bottom of the Earth, two miles below Antarctica's ice sheet, scientists have broken a 20-million-year silence. A Russian team has drilled 3,770 metres (2.3 miles) through the polar ice to a vast freshwater lake, called Lake Vostok. It has lain undisturbed for four times as long as human beings have been separate from apes.


Antarctica's 15-Million Year-Old Lake -A Living Bio Lab?   Daily Galaxy - January 20, 2009

Lake Vostok is located beneath four kilometers of ice in East Antarctica. The lake is approximately 250 km long and 50 km wide. The overlying ice provides a continuous paleo-climatic record of 400,000 years, although the lake water itself may have been isolated for as long as 15 million years. Because of the long isolation, it's believed that Lake Vostok could contain new lifeforms, and unique geochemical processes. For five years, scientists in Russia and the United States have sought to probe the ancient lake to discover the secrets lying inside this pristine body of water.

A major issue is the reality that it is impossible to penetrate an isolated ecosystem without contaminating it. The catch 22 inherent in Lake Vostok is that the very thing that make it potentially unique: because of its millennia of isolation from the rest of the world, it cannot be explored without introduction of microbes from the outer world. NASA has expressed interest in exploring the lake to search for microbes that might be similar to ones on other planets. How the bacteria get energy to survive is an important unanswered question. The lake could be an analog to Jupiter's moon Europa or subsurface where conditions are similar.




Extraterrestrial Lakes


Spring on Saturn's Moon Titan Reveals Amazing Views of Otherworldly Lakes (Photos)   Live Science - October 25, 2013

NASA's Cassini space probe is getting an exceptional look at the vast liquid lakes of Titan's north pole, where dense winter clouds are finally retreating thanks to a change in seasons on Saturn's largest moon. A clearer view of Titan's wet northern region could provide clues about the moon's hydrologic cycle and the evolution of its seas. New images released by NASA this week even revealed the Titan equivalent of salt flats surrounding its northern lakes, some of which are as big as the Caspian Sea and Lake Superior combined. Titan more closely resembles Earth than any other planet or moon in our solar system, with a dense atmosphere and stable liquids on its surface. But Titan's clouds, lakes and rain are made up of hydrocarbons, such as ethane and methane, rather than water.





At present the surface of the planet Mars is too cold and has too little atmospheric pressure to permit the pooling of liquid water on the surface. 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 lakes. Under current conditions this water would quickly freeze and evaporate unless insulated in some manner, such as by a coating of volcanic ash.





Only one world other than Earth is known to harbor 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.





Jupiter's small moon Io is volcanically active due to tidal stresses, 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 on the surface.





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.




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