) or PSU (Practical Salinity Units) units of the Practical Salinity Scale.
| Element | Content, mg/l |
|---|---|
| Chlorine | 19 500 |
| Sodium | 10 833 |
| Magnesium | 1 311 |
| Sulfur | 910 |
| Calcium | 412 |
| Potassium | 390 |
| Bromine | 65 |
| Carbon | 20 |
| Strontium | 13 |
| Bor | 4,5 |
| Fluorine | 1,0 |
| Silicon | 0,5 |
| Rubidium | 0,2 |
| Nitrogen | 0,1 |
Salinity in ppm is the amount of solids in grams dissolved in 1 kg of seawater, provided that all halogens are replaced by an equivalent amount of chlorine, all carbonates are converted to oxides, organic matter burned.
In 1978, the practical salinity scale (PSS-78) was introduced and approved by all international oceanographic organizations, in which the measurement of salinity is based on electrical conductivity (conductometry), and not on water evaporation. Oceanographic CTD sounders became widely used in marine research in the 1970s, and since then salinity has been measured primarily electrically. To check the operation of electrical conductivity cells that are immersed in water, laboratory salt meters are used. In turn, standard sea water is used to check salinity meters. Standard sea water recommended international organization IAPSO for checking salinity meters, produced in the UK by the Ocean Scientific International Limited (OSIL) laboratory from natural sea water. If all measurement standards are met, a salinity measurement accuracy of up to 0.001 PSU can be achieved.
The PSS-78 scale produces numerical results similar to mass fraction measurements, and differences are noticeable either when measurements with precision better than 0.01 PSU are required or when the salt composition does not correspond to the standard composition of ocean water.
- Atlantic Ocean - 35.4 ‰ The highest salinity of surface waters in the open ocean is observed in the subtropical zone (up to 37.25 ‰), and the maximum is in the Mediterranean Sea: 39 ‰. In the equatorial zone, where the maximum amount of precipitation is recorded, salinity decreases to 34 ‰. A sharp desalination of water occurs in the estuary areas (for example, at the mouth of La Plata - 18-19 ‰).
- Indian Ocean - 34.8 ‰. The maximum salinity of surface waters is observed in the Persian Gulf and the Red Sea, where it reaches 40-41 ‰. High salinity (more than 36 ‰) is also observed in the southern tropical zone, especially in the eastern regions, and in the northern hemisphere also in the Arabian Sea. In the neighboring Bay of Bengal, due to the desalinating influence of the Ganges runoff with the Brahmaputra and Irrawaddy, the salinity is reduced to 30-34 ‰. The seasonal difference in salinity is significant only in the Antarctic and equatorial zones. In winter, desalinated waters from the northeastern part of the ocean are transported by the monsoon current, forming a tongue of low salinity along 5° N. w. In summer this language disappears.
- Pacific Ocean - 34.5 ‰. Tropical zones have the highest salinity (up to a maximum of 35.5-35.6 ‰), where intense evaporation is combined with a relatively small amount of precipitation. To the east, under the influence of cold currents, salinity decreases. High precipitation also reduces salinity, especially at the equator and in the westerly circulation zones of temperate and subpolar latitudes.
- Arctic Ocean - 32 ‰. In the Arctic Ocean there are several layers of water masses. The surface layer has a low temperature (below 0 °C) and low salinity. The latter is explained by the desalination effect of river runoff, melt water and very weak evaporation. Below there is a subsurface layer, colder (up to −1.8 °C) and more saline (up to 34.3 ‰), formed when surface waters mix with the underlying intermediate water layer. The intermediate water layer is Atlantic water coming from the Greenland Sea with a positive temperature and high salinity (more than 37 ‰), spreading to a depth of 750-800 m. Deeper lies the deep water layer, which is formed in winter also in the Greenland Sea, slowly creeping in a single stream from the strait between Greenland and Spitsbergen. The temperature of deep waters is about −0.9 °C, salinity is close to 35 ‰. .
The salinity of ocean waters varies depending on latitude, from the open part of the ocean to the shores. In the surface waters of the oceans, it is lower in the equator region, in polar latitudes.
| Name | Salinity, ‰ |
|---|---|
02/10/2016 at 21:20 · Pavlofox · 71 770
The saltiest seas in the world
There are about 80 seas around the world that are integral part World ocean. All these waters are salty, but among them there are record holders, which are distinguished by a high concentration of salts and other minerals in their composition. The most fresh sea on the planet the Baltic Sea is considered, the salinity of which is only 7 ‰ (ppm), which is equal to 7 grams per 1 liter of water. Among all the others, we singled out the saltiest seas in the world.
10. White Sea | Salinity 30‰
Among the most salty seas peace. Salinity here can reach 30‰ in places. This is one of the smallest seas in Russia, with an area of 90,000 square meters. km. The temperature here rises to 15 degrees in the summer and drops to minus 1 degree in the winter. The inhabitants of the White Sea are about 50 species of fish, including beluga whale, salmon, cod, smelt and others.
9. Chukchi Sea | Salinity 33‰
It is one of the ten saltiest in the world. Its salinity in winter is higher and can reach 33‰. It is located between Chukotka and Alaska on an area of 589,600 sq. km. The water temperature here is quite low: in summer – 12 degrees above zero, and in winter – minus 1.8 degrees. Walruses, seals, as well as fish - grayling, polar cod, Far Eastern navaga, Arctic char and others live here.
8. Laptev Sea | Salinity 34‰
Occupying an area of 662,000 sq. km., are considered to be the saltiest in the world. It is located between the New Siberian Islands and the Severnaya Zemlya Islands. The salinity of its waters reaches 34‰ in some places, and the water temperature does not rise above 0 degrees all year round. IN sea depths The area is inhabited by walrus, sterlet, sturgeon, perch and other animals.
7. Barents Sea | Salinity 35‰
Having a salinity of 35‰, it is one of the saltiest on earth and the saltiest in Russia. It is washed by the waters of the White Sea and has an area of 1,424,000 sq. km. In winter, only the southwestern part of the sea does not freeze; the temperature here in summer does not exceed plus 12 degrees. The underwater world here is quite rich in fish, including capelin, perch, herring, catfish, killer whale, beluga and others.
6. Sea of Japan | Salinity 35‰
Located between the shores of Eurasia, the Japanese islands, and the island of Sakhalin, it is considered one of the saltiest in the world. Its salinity reaches 35‰. The annual water temperature ranges from 0–+ 12 degrees in the north, and in the southern part 17-26 degrees above zero. Animal world The fish here is very rich and includes many species of fish. Herring, pollock, navaga, flounder, pink salmon, chum salmon, anchovy, crabs, shrimp, oysters, squid and many others live here. Japanese salt waters occupy an area of 1,062,000 sq. km.
5. Ionian Sea | Salinity 38‰
considered the densest and saltiest in Greece. It is perfect for those who do not know how to swim and want to learn. In summer, the temperature here ranges from 25-26 degrees above zero, and in winter it drops to plus 14 degrees. The salinity of the sea is about 38‰. The inhabitants of salt waters are fish such as tuna, flounder, mackerel and others. The Ionian Sea occupies an area of 169,000 sq. km.
4. Aegean Sea | Salinity 38.5‰
Aegean It is one of the ten saltiest seas in the world. Its salinity is about 38.5‰. Due to the high salinity, it is recommended to take a bath after swimming in such water. fresh water, because high concentration sodium can adversely affect the skin and mucous membranes. Winter temperatures here are about 14 degrees above zero, and summer temperatures are plus 24 degrees. It is inhabited by octopuses, sardines, sponges and other inhabitants. It is located between the peninsulas of the Balkans, Asia Minor and the island of Crete. The Aegean Sea has existed for about 20,000 years. It was formed as a result of the flooding of the Egenida landmass and occupied an area of 179,000 sq.m. Its appearance led to the formation of the islands of Crete, Lesbos, Euboea and others.
3. Mediterranean | Salinity 39.5‰
Located between Europe and Africa. It is rightfully considered one of the saltiest seas in the world, the salinity of which in some places reaches 39.5 ‰. It also belongs to the warmest seas of the World Ocean - the temperature here is plus 25 degrees in summer and minus 12 degrees in winter. It is inhabited by seals, sea turtles, as well as more than 500 species of fish, including sharks, stingrays, blennies, lobsters, crabs, mussels and many, many others.
2. Red Sea | Salinity 42‰
Located between Africa and Asia, it is one of the saltiest on planet Earth. Its salinity reaches 42 ‰, which is about 41 grams per liter of water. The very rich are concentrated here undersea world: sharks, dolphins, rays, moray eels and other living creatures are inhabitants of the Red Sea. The water temperature is 25 degrees above zero all year round. In the Red Sea, the water is very well and evenly mixed. In winter, surface water cools, becomes denser and sinks down, and rises up warm waters from the depths. In summer, water evaporates from the surface of the sea, and the remaining water becomes saltier, heavier and sinks. Less salty water rises in its place. Thus, all year round the water in the sea is intensively mixed, and throughout its entire volume the sea is the same in temperature and salinity, except in the depressions. In addition, the sea boasts amazing transparency.
1. Dead Sea | Salinity 270‰
- the saltiest in the world, which is located on the border of Israel and Jordan. The mineral content is about 270 ‰, and the salt concentration per 1 liter reaches 200 grams. The composition of the salts of the sea differs significantly from all others. It consists of 50% magnesium chloride, and is also rich in potassium, bromine, calcium and many other mineral elements. Potassium salts are artificially crystallized from its water. The water here has the highest density, which is 1.3-1.4 g/m³, which completely eliminates the possibility of drowning. In addition to unique salts, the sea contains healing mud, which contain 45% salts. Its features are a high pH value of 9, as well as a bitter and oily taste. Sea temperatures can reach 40 degrees above zero, which creates intense evaporation and contributes to high density. If in other waters with high salinity there are diverse inhabitants, then in the waters of the Dead Sea it is impossible to meet them.
Sea water covers two-thirds of our planet and has many unique properties. Main characteristics sea water - its salinity, which differs in different parts of the planet: from 41–42 g/l in the saltiest sea to 7 g/l in the freshest. The average salinity of the World Ocean is 34.7 g/l. What is the saltiest sea in the world?
The Red Sea is the saltiest sea in the world
It is the Red Sea that is known as the saltiest sea on our planet. The density of salts in its water is 41 g/l, which is a third higher than the average salt content in the World Ocean. But this does not bother its many inhabitants. The rich flora and fauna of the Red Sea attract thousands of tourists, especially lovers of underwater tourism - diving.
By the way, if someone decides to argue with you about which sea is the saltiest - the Dead Sea, whose waters contain 270 g/l of salts, or the Red Sea, you can confidently answer that it is Red. The fact is that the Dead Sea, despite its name, is from a scientific point of view a lake, since its waters have no drainage.
In turn, the Red Sea is distinguished by the fact that it does not have a single river that flows into it. This is one of the reasons why the water in it is so salty. The climate here is very dry and hot. Water evaporates at a tremendous speed - up to 2 thousand mm per year, but the salt remains. Rains are not able to replenish this amount of evaporation: in total, less than 100 mm of precipitation falls here per year. For comparison: in the central and northern parts of Kazakhstan, 300 falls per year. – 500 mm of precipitation, in Turkey - 400 – 700 mm, in Ukraine - 600 – 800 mm, in Central Africa - 1800– 3000 mm per year.
The Red Sea belongs to the basin Indian Ocean. It would probably have dried up long ago if not for the Gulf of Aden, which allows it to exchange waters with the ocean. Currents move in both directions and replenish the water balance of the Red Sea by thousands of liters per year. On the other hand, it is connected to the Mediterranean Sea thanks to the Suez Canal. There is also a current here, although to an insignificant extent for the scale of the sea.
Sandwiched between the northeastern coast of Africa and the Arabian Peninsula, the Red Sea stretches for more than 2 thousand km. However, even at its widest point it remains narrower than many rivers - only 360 m. In some places its depth reaches 2.2 km, although the average depth of the saltiest sea in the world is only 437 m.
Despite its large extent, the salinity of the waters of the Red Sea has almost the same characteristics throughout its entire area (which, by the way, is 450 thousand km2). This is due to the unique natural mechanism of water mixing. In winter, the cooling water sinks to the bottom, and the retaining heat rises to the top. In summer, the water on the surface becomes heavier due to evaporation and increased salinity, so this giant mixer works all year round.
Hot depressions, discovered by scientists no more than half a century ago, contribute to the mixing of water. Observations of the temperature and composition of the waters in these depressions suggest that they are heated by heat coming from the bowels of the Earth. So, average temperature water in the Red Sea stays at 20 throughout the year – 25 °C, and in the depressions - 30 – 60 °C, and increases by 0.3 annually – 0.7 °C.
Rivers carry with them not only water, but also sand, silt and debris, so the Red Sea, as the only body of water in the world without river flow, retains the incredible clarity of its waters. This turns it into one of the most picturesque places on the planet. Coral reefs, thousands of species of colorful fish, numerous algae, including the one that gave the sea its name - all this is worth seeing with your own eyes. It is important to note that about a third of the local inhabitants are endemic, which means they can only be found here.
The saltiest seas: list
The main contenders for the status of the saltiest seas in the world are:
Mediterranean Sea.
The second place in the list of the saltiest seas after the Red Sea is occupied by the Mediterranean Sea - 39.5 g/l. Although such salinity can only be felt far from the coast, it still significantly limits the development of small algae and zooplankton, increasing the transparency of sea waters. Like the Red Sea, the Mediterranean Sea is one of the most warm seas planets: even in winter the water temperature here does not drop below 10 – 12 °C, and in summer it warms up to 25 – 28°C.
Aegean Sea.
The next in salinity is the Aegean Sea, which washes the shores of Greece and Turkey, as well as the famous island of Crete. Here the water contains an average of 38.5 g/l of salts, which are high in sodium. Doctors recommend that you rinse off after swimming in this sea to avoid corroding the surface layers of the skin.
Ionian Sea.
Another Greek sea is only slightly behind in salinity - the Ionian Sea, whose water contains on average 38 g/l of salts. Here, the high alkali content also forces tourists to be more careful about their skin. But high density (highest for seawater) combined with high temperature water (26 – 28 °C in summer) maintains the attractiveness of these places.
Ligurian Sea.
Density saline solution The Ligurian Sea also has 38 g/l. This small sea with an area of only 15 thousand km2 is located between the island of Corsica and the Tuscan coast. The many streams flowing into it from the Apennines could not add freshwater to it.
Barencevo sea.
The Barents Sea has a salinity of 35 g/l - the saltiest sea in Russia. It is located in the north of the European part of Russia and combines the warm waters of the Atlantic Ocean and the cold waters of the Arctic Ocean.
Also in the top ten saltiest seas are the Sea of Japan, known for its typhoons (37 – 38 g/l), Laptev Sea (34 g/l), Chukchi Sea (33 g/l) and White Sea (30 g/l).
Interestingly, the Aral Sea, located on the borders of Kazakhstan and Uzbekistan, which, like the Dead Sea, is more of a lake than a sea, may soon catch up with it in terms of water salinity. This reservoir, which in the mid-twentieth century occupied the 4th largest area among the planet’s lakes, became so shallow that its area decreased almost 10 times - from 68.9 thousand km2 to 7.3 thousand km2 - in 2014. During the same time, water salinity increased 10 times and in 2007 reached 100 g/l.
Despite the diversity, the salinity of the waters in the World Ocean is much more stable - over the past 50 years, scientists have not been able to notice significant fluctuations. So, when your children and grandchildren begin to wonder which sea is the saltiest in the world, the answer will remain the same - Red. We wish you to someday experience the unique composition of its waters on your own skin and see with your own eyes the diversity of its underwater inhabitants.
Salinity is the amount of dissolved solid minerals (salts), expressed in grams, in 1 kg of sea water. The thousandth part of a whole is called ppm and is indicated by the symbol %o. For example, if the salinity of ocean water is 35%o, this means that 1 kg (1000 g) of this water contains 35%o (ppm) of dissolved substances.
Salinity is one of the main characteristics of sea water; its value expresses the degree of concentration of all substances dissolved in water (mainly salts).
The value of salinity in a particular area of the World Ocean depends on a number of factors: the influx of fresh water and the amount of precipitation, the intensity of water evaporation, the formation and melting of ice and water mixing processes.
As seawater evaporates, the salinity of seawater increases as the salts remain in solution. As sea ice melts, salinity decreases because sea ice typically has less salinity than 
salinity of surrounding waters.
When sea ice forms, salinity increases due to the fact that only part of the salts pass into the ice.
What is the salinity of the waters of the World Ocean and its geographical distribution?
Salinity in different places, both on the surface and in the depths of oceans and seas, is not the same. The average salinity of the waters of the World Ocean is 35%. 
In the open parts of the oceans, salinity changes little (from 32 to 37.9%o), in the seas it varies significantly more - from 2 (in the Gulf of Finland of the Baltic Sea) to 42%o (in the Red Sea).
The general pattern of changes in salinity across latitudes under the influence of precipitation and evaporation regimes is typical for all oceans: salinity increases in the direction from the poles to the tropics, reaches a maximum value around 20-25° northern and southern latitudes and decreases again in the equatorial zone.
The uniform change in salinity in the surface layers is disrupted by the influence of oceanic and coastal currents and enrichment 
fresh waters large rivers. The highest salinity of the World Ocean (S = 37.9%o, not counting some seas, is west of the Azores.
The salinity of the seas differs the more from the salinity of the ocean, the less the seas communicate with it; it also depends on their geographical location, in particular from climatic conditions. The salinity of the seas is greater than that of the oceans: the Mediterranean - in the west 37-38%0, in the east - 38-39%0;
The salinity of the Red Sea is 37%o in the south, and up to 42%o in the north, in the Persian Gulf in the north the salinity is 40%o, in the eastern part - from 37 to 38%o.
Salinity: in the Sea of Azov in the middle part is from 10 to 12%o, and off the coast - 9.5%o. 
The salinity of water in the Black Sea, in the middle part, is from 10 to 12%o, and in the northwestern part - 17%o, with increasing depth of the sea, the salinity of the water increases to 22%o;
in the Baltic Sea with eastern winds - 10%o, with western and southwestern winds - from 10 to 22%o; in the Gulf of Finland near the island of Kotlin - 2%0; in the White Sea on the border with the Barents Sea it is 34-34.5%o, in Gorlo - 27-30%o, and in the middle part - from 24 to 27%o.
In the Caspian Sea, salinity is 12.8%o and in 
The average salinity of the Aral Sea is 10.3%.
The salinity of the Russian Arctic and Far Eastern seas in areas remote from the coast is 29-30%.
With increasing depth, salinity changes only up to 1500 m, below this horizon and to the bottom - insignificantly and ranges from 34 to 35%.
In the polar regions, when ice melts, salinity increases with depth; when ice forms, the salinity of sea water decreases. 
IN temperate latitudes The salinity of sea water varies little with depth, in subtropical zone it quickly decreases to a depth of SOO-1500 m, in the tropical it increases to a depth of 100 m, then decreases to a depth of 500 m, after which it increases slightly to a depth of 1500 m, and below remains unchanged.
What is the significance of the salinity and density of sea water?
As the temperature decreases, the density of salty sea water increases, that is, the sea is saltier in winter than in summer! During autumn and winter cooling, the water on the sea surface becomes denser and heavier. 
With further cooling, surface sea water, being denser and heavier, “sinks” and mixes with warmer and lighter deep water.
This feature of salty sea water helps to moderate the Earth's climate. When cooling 1 cu. see sea water at 19C 3134 cubic meters. see the air heats up by 1 °C.
The salinity of sea water increases vertical circulation in the oceans and seas. The air receives much more heat (thermal energy) from the salty waters of the World Ocean than it would receive if the ocean waters were fresh.
The intensity of freezing of sea water and the development of ice phenomena in the seas and oceans depend on salinity. 
The horizontal and vertical distribution of seawater density promotes horizontal and vertical water circulation.
Knowing the vertical distribution of the density of sea water, it is possible to determine the direction and speed of currents, as well as the stability of a particular water mass: if the mass is unstable, then denser water lies above less dense water, and the waters will mix (vertical circulation). 
The density of sea water is great importance for the inhabitants of the ocean. The stability of the water composition, which affects the distribution of organic and inorganic matter in the ocean, depends on it.
The density of water affects the draft of ships. When moving from ocean water in fresh water and vice versa, their draft can vary up to 0.3 m. Therefore, for proper loading of ships in 
ports and ensuring the safety of navigation, it is necessary to know the value of salinity and density at the port of loading and at the transition to the sea to the port of destination and take them into account correctly.
The Earth can be confidently called a water planet, because the World Ocean surrounding the land covers 71% of its entire surface. , included in its composition, differ from each other in many ways. Including such a parameter as salinity, which means the amount of salts dissolved in one liter of water under certain conditions. The salinity of sea water is most often measured in “‰” (ppm). Now it won’t be difficult to find out which is the saltiest sea on Earth.
5. Ionian Sea - salinity exceeds 38 ‰
The Ionian Sea is the part of the Mediterranean that washes the shores of southern Italy and Greece. The bottom of the sea is covered with silt, and closer to the shores - with sand and small shell rock. Its area is 169 thousand km², maximum depth is 5,121 m. This is the most great depth throughout the Mediterranean Sea. Commercial fishing of mackerel, mullet, tuna, and flounder is carried out. The waters of the Ionian Sea are safe and very warm, even in February their temperature does not fall below 14°C, and at peak holiday season, in August, reaches 25.5°C. Among its inhabitants are bottlenose dolphins, huge turtles, and octopuses. And very dangerous sea urchins and white sharks can hardly be found near the coast. Poisonous dragon fish, which can cause an allergic reaction in humans, are more active at night and burrow into the sand during the day.
4. Aegean Sea - salinity from 37 to 40.0 ‰
This semi-enclosed sea has about 20,000 islands and is located in the eastern Mediterranean. The total area is 179 thousand km². Through the straits it is connected to Mramorny, Cherny and Mediterranean seas. The salinity of its waters is increasing, which is associated with global warming. After swimming, it is recommended to rinse off the sea water, as this can negatively affect the condition of the skin and mucous membrane of the eyes. There is a fishing industry in the Aegean Sea; sponges are actively mined and octopuses are caught. Due to the fact that there is little plankton in this sea, fishing in its waters is gradually declining.
3. Ligurian Sea - salinity 38 ‰
This sea is located in the western part of the Mediterranean. The shores are steep and rocky, but there are sandy beaches. Many small rivers flow into the Ligurian Sea, which originate in the Apennines. On its shores there are such important ports as:
- Limpia, which is considered the sea gate of Nice.
- Cruise ports of Savona, La Spezia, with container and bulk terminals.
- Genoese port, ranking first in terms of trade volume in Italy.
Despite high salinity These waters, on the French-Italian coast of the Ligurian Sea, is located one of the most famous resort areas in the world - the Riviera.
2. Mediterranean Sea - salinity from 36 to 39.5 ‰
The Mediterranean Sea is a relic of the ancient Tethys Ocean. It is considered one of the largest seas in size, its area is 2.5 million km². Its basin includes the Sea of Azov, Black and Marmara. The salinity of the sea fluctuates significantly, as water with a much lower salinity enters from the Atlantic through the Strait of Gibraltar. The amount of zooplankton in the Mediterranean Sea is relatively small, and as a result there are few various types fish, as well as marine animals and mammals. But in large quantities algae are represented, especially peridinea and diatoms. The bottom fauna is very poor due to yellowish silt, which is not conducive to the development of life. There are 550 species of fish in the Mediterranean Sea, 70 of which are endemic. The most common species are: mackerel, sardine, horse mackerel, mullet, etc. There are also larger “inhabitants” - sharks, rays, tuna. Edible shellfish are common.
1. Red Sea - salinity 41 ‰
The saltiest of all, the Red Sea is located in a tectonic depression, the depth of which can reach 3 km. It is an inland sea of the Indian Ocean. The hot climate, which provokes strong surface evaporation and low precipitation (about 100 mm per year), and the absence of rivers flowing into the sea, leads to a gradual increase in its salinity. Due to the absence of silt and sand, which are abundant in river water The Red Sea is distinguished by its extraordinary transparency and purity. The water temperature even in winter is +20 °C, and in summer it is much higher.
Despite its salinity, the waters of the Red Sea amaze with the huge number of different species of fish living in it. But ichthyologists believe that only 60% of fish capable of existing at great depths have been discovered. The sea is extremely beautiful, and it has many interesting and sometimes funny inhabitants, but touching them is strictly prohibited. Corals, sponges, jellyfish, and sea urchins, moray eels and poisonous sea snakes potentially extremely dangerous. Any contact with them can result in a burn, significant blood loss or a severe allergic reaction, and sometimes death. 44 species of sharks live in warm sea waters. The most terrible of them is the tiger, which can easily attack a person.
Having examined them separately, it is now easy to conclude which is the saltiest sea. The salinity of the very famous Dead Sea reaches 350 ‰, but in fact, despite its name, it is an endorheic lake that is gradually drying up.