The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, such as the alga Dunaliella salina and fungus Wallemia ichthyophaga. Some well-known species give off a red color from carotenoid compounds, notably bacteriorhodopsin. Halophiles can be found in water bodies with salt concentration more than five times greater than that of the ocean, such as the Great Salt Lake in Utah, Owens Lake in California, the Urmia Lake in Iran, the Dead Sea, and in evaporation ponds. They are theorized to be a possible analogues for modeling extremophiles that might live in the salty subsurface water ocean of Jupiter's Europa and similar moons.
Salinity is the saltiness or amount of salt dissolved in a body of water, called saline water. It is usually measured in g/L or g/kg.
The Great Salt Lake is the largest saltwater lake in the Western Hemisphere and the eighth-largest terminal lake in the world. It lies in the northern part of the U.S. state of Utah and has a substantial impact upon the local climate, particularly through lake-effect snow. It is a remnant of Lake Bonneville, a prehistoric body of water that covered much of western Utah.
An evaporite is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of water such as lakes. Evaporites are considered sedimentary rocks and are formed by chemical sediments.
An endorheic basin is a drainage basin that normally retains water and allows no outflow to other external bodies of water, such as rivers or oceans, but drainage converges instead into lakes or swamps, permanent or seasonal, that equilibrate through evaporation. They are also called closed or terminal basins, internal drainage systems, or simply basins. Endorheic regions contrast with exorheic regions. Endorheic water bodies include some of the largest lakes in the world, such as the Caspian Sea, the world's largest inland body of water.
Natural salt pans or salt flats are flat expanses of ground covered with salt and other minerals, usually shining white under the sun. They are found in deserts and are natural formations.
A salt lake or saline lake is a landlocked body of water that has a concentration of salts and other dissolved minerals significantly higher than most lakes. In some cases, salt lakes have a higher concentration of salt than sea water; such lakes can also be termed hypersaline lakes, and may also be pink lakes on account of their colour. An alkalic salt lake that has a high content of carbonate is sometimes termed a soda lake.
Lake Magadi is the southernmost lake in the Kenyan Rift Valley, lying in a catchment of faulted volcanic rocks, north of Tanzania's Lake Natron. During the dry season, it is 80% covered by soda and is well known for its wading birds, including flamingos.
In oceanography, a halocline is a cline, a subtype of chemocline caused by a strong, vertical salinity gradient within a body of water. Because salinity affects the density of seawater, it can play a role in its vertical stratification. Increasing salinity by one kg/m3 results in an increase of seawater density of around 0.7 kg/m3.
A salt evaporation pond is a shallow artificial salt pan designed to extract salts from sea water or other brines. The Salt pans are shallow and large of size because it will be easier for sunlight to travel and reach the sea water. Natural salt pans are geological formations that are also created by water evaporating and leaving behind salts. Some salt evaporation ponds are only slightly modified from their natural version, such as the ponds on Great Inagua in the Bahamas, or the ponds in Jasiira, a few kilometres south of Mogadishu, where seawater is trapped and left to evaporate in the sun.
Lake Assal is a crater lake in central-western Djibouti. It is located at the western end of Gulf of Tadjoura between Arta Region, and Tadjoura Region, touching Dikhil Region, at the top of the Great Rift Valley, some 120 km (75 mi) west of Djibouti city. Lake Assal is a saline lake that lies 155 m (509 ft) below sea level in the Afar Triangle, making it the lowest point on land in Africa and the third-lowest point on Earth after the Sea of Galilee and the Dead Sea. No outflow occurs from the lake, and due to high evaporation, the salinity level of its waters is 10 times that of the sea, making it the third most saline body of water in the world behind Don Juan Pond and Gaet'ale Pond. The salt in the lake is exploited under four concessions awarded in 2002 at the southeast end of the lake; the major share of production is held by Société d’Exploitation du Lac and Société d’Exploitation du Salt Investment S.A de Djibouti.
Don Juan Pond is a small and very shallow hypersaline lake in the western end of Wright Valley, Victoria Land, Antarctica, 9 kilometres (5.6 mi) west from Lake Vanda. It is wedged between the Asgard Range to the south and the Dais Range to the north. On the west end is a small tributary and a rock glacier. With a salinity level of 33.8%, Don Juan Pond is the saltiest of the Antarctic lakes. This salinity causes significant freezing-point depression, allowing the pond to remain liquid even at temperatures as low as −50 °C (−58 °F).
A brine pool, sometimes called an underwater lake, deepwater or brine lake, is a volume of brine collected in a seafloor depression. The pools are dense bodies of water that have a salinity that is three to eight times greater than the surrounding ocean. Brine pools are commonly found below polar sea ice and in the deep ocean. Those below sea ice form through a process called brine rejection. For deep-sea brine pools, salt is necessary to increase the salinity gradient. The salt can come from one of two processes: the dissolution of large salt deposits through salt tectonics or geothermally heated brine issued from tectonic spreading centers. The brine often contains high concentrations of hydrogen sulfide and methane, which provide energy to chemosynthetic organisms that live near the pool. These creatures are often extremophiles and symbionts. Deep-sea and polar brine pools are toxic to marine animals due to their high salinity and anoxic properties, which can ultimately lead to toxic shock and possibly death. The frequency of brine pool formation coupled with their uniquely high salinity has made them a candidate for research regarding ways to harness their properties to improve human science.
Pink Lake is a salt lake in the Goldfields-Esperance region of Western Australia. Although historically the water in the lake was visibly pink, as of 2017 it had not been pink for over ten years. Salt concentration is vital to Pink Lake's pink hue, and Pink Lake may turn pink again as conditions change. It lies about 3 kilometres (2 mi) west of Esperance and is bounded to the east by the South Coast Highway.
Blood Falls is an outflow of an iron oxide-tainted plume of saltwater, flowing from the tongue of Taylor Glacier onto the ice-covered surface of West Lake Bonney in the Taylor Valley of the McMurdo Dry Valleys in Victoria Land, East Antarctica.
The Danakil Depression is the northern part of the Afar Triangle or Afar Depression in Ethiopia, a geological depression that has resulted from the divergence of three tectonic plates in the Horn of Africa.
Mars habitability analogue environments on Earth are environments that share potentially relevant astrobiological conditions with Mars. These include sites that are analogues of potential subsurface habitats, and deep subsurface habitats.
Gaet'ale Pond is a small hypersaline lake located near the Dallol crater in the Danakil Depression. It is located over a hot spring of tectonic origin and has no apparent inlet or outlet streams. The water of Gaet'ale Pond has a salinity of 43%, making it the saltiest water body on Earth.
Dallol is a unique, terrestrial hydrothermal system around a cinder cone volcano in the Danakil Depression, northeast of the Erta Ale Range in Ethiopia. It is known for its unearthly colors and mineral patterns, and the very acidic fluids that discharge from its hydrothermal springs.
