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Why do lakes disappear on earth
Why do lakes disappear on earth
Anonim

Recently in Antarctica, a huge glacial lake disappeared as a result of hydraulic fracturing - water left it through a crack in the glacier. However, this is far from the first such case in the history of the Earth. We will tell you which lakes have already disappeared and which are on the verge.

A large body of water such as a lake may seem like a permanent feature in the landscape, but this is not always the case.

Some lakes appear and disappear naturally from year to year, as the flow of water in and out of them changes over the course of several months. For others, when they are gone, they are gone forever. Climate change is of concern in some places, such as sub-arctic lakes that depend on snow melt.

The reasons for the disappearance of the lakes are varied. These are the bodies of water that no longer exist or are threatened with extinction.

Lake Urmia, Iran

This salt lake, located in the northwestern corner of Iran, was once the largest in the country, but quickly receded from the shores. Climate change, wasteful irrigation practices (fresh water is diverted before it reaches the lake) and depletion of groundwater account for a significant proportion of water losses.

In addition, the dams cut off most of the new water supply to the lake.

According to local environmental authorities, the lake has only about five percent of the water left, compared with its volume about 20 years ago. All that remains of the reservoir is mostly a dry bed.

Lake Waiau, Hawaii

Lake Waiau has never been considered a large body of water. The only alpine lake in Hawaii is only 6,900 m² and 3 m deep. But for the indigenous Hawaiians, the reservoir was considered sacred. According to the myth, the lake was bottomless and was a portal to the world of spirits.

But in early 2010, the lake began to shrink, and by September 2013 it was more like a pond, occupying only 115 m². At the same time, its depth was 30 cm. Such a decrease is "unprecedented in our time," the US Geological Survey reported in 2013. The reason for the depletion of the lake is still unknown. However, experts tend to believe that the drought is to blame.

Dead Sea; Israel, West Bank and Jordan

The water level in the Dead Sea is 430 m (09.2015) below sea level and falls at a rate of about 1 meter per year. The coast of the lake is the lowest land area on Earth. The Dead Sea is one of the saltiest bodies of water on Earth, salinity is 300-310 ‰, in some years up to 350 ‰. The length of the sea is 67 km, the largest width is 18 km, the maximum depth is 306 m. The volume of water is 147 km³.

The Dead Sea has existed for thousands of years because the amount of water entering the lake was more or less equal to the amount that evaporated from it. But as the region's population grew, that equation became unbalanced. The water that once flowed into the Dead Sea has been used to supply people's homes and water-intensive industries such as chemical and potash companies. Currently, the lake receives less than a tenth of the water than several decades ago, so the water level in the Dead Sea drops by about a meter per year.

Aral Sea, Kazakhstan and Uzbekistan

Until 1960, the Aral Sea occupied the second place in the world among inland closed lakes after the Caspian Sea, and the fourth place among lakes after Victoria (Tanzania, Kenya, Uganda), Upper Lake (Canada, USA) and the same Caspian Sea. In the 2000s, experts started talking about the transformation of a once powerful reservoir into a new desert - Aralkum.

Before the shallowing began, the Aral Sea was the fourth largest lake in the world.

Since that time, ninety percent of the river flow from the Tien Shan mountains into the lake has been directed to irrigate rice and cotton fields sown with desert lands.As a result, the water level in the lake began to drop rapidly. Fishing in the lake has stopped and shipping has decreased. The open bottom of the lake has become a source of salt, which is carried by winds within a radius of 300 kilometers and contaminates agricultural land.

In 2014, the eastern part of the South (Big) Aral Sea completely dried up, reaching that year the historical minimum area of ​​the entire sea of ​​7297 km². Having temporarily spilled in the spring of 2015 (up to 10780 km² of the entire sea), by the fall of 2015 its water surface again decreased to 8303 km².

Lake Penier, USA

Lake Penier in the US state of Louisiana once simply spilled into a salt mine, forming the largest whirlpool ever created by man.

The reason for the strange disaster at Lake Peñeres was the human factor. The Texaso oil and gas company was extracting oil from the bottom of the lake, but they accidentally punctured the roof of the mine, which ran under the lake at a depth of 400 meters.

The collapse of the mine created a whirlpool abruptly. The funnel expanded until it reached 55 meters in diameter. It sucked in the rig itself, the tug and 11 barges. Then landslides began, because of them the dock, an islet with a botanical garden, houses by the lake, trucks, and the surrounding forest collapsed into a whirlpool. The lake emptied into the Gulf of Mexico, from which it pulled water at 1 meter of water level in the bay. In an instant, the freshwater lake turned into salty.

But everyone was lucky, no one died. About 50 people were saved, and the barges surfaced back a couple of days later.

Lake Kashe ll, Chile

This lake, located high in the Andes, disappeared over the night of March 31, 2012. But that wasn't all that unusual for the lake, at least recently - it has disappeared and refilled several times since 2008. The lake is a glacial lake blocked by a dam. Climate change has led to a thinning of the glacier, which has allowed the tunnel under the eight-kilometer depth to open and close repeatedly, draining the lake and allowing it to refill many times. Until 2008, the state of the lake was relatively stable.

Lake Cachuma, California

This lake in southern California, near Santa Barbara, is a popular holiday destination and a critical source of drinking water for 200,000 people. But now the lake is only 39.7% full. California is in the midst of a devastating drought that is not expected to end anytime soon, and the future of Lake Cachuma remains in question.

Lake Chad; Chad, Cameroon, Niger and Nigeria

Lake Chad, once the sixth largest lake in the world, has lost 90 percent of its area since it began to shrink in the 1960s. Persistent drought, water withdrawals for irrigation and other human needs, as well as climate variability have all led to the disappearance of the lake. “The changes in the lake have contributed to local water shortages, crop failures, livestock deaths, fishing cessation, soil salinization and increased poverty across the region,” says a 2008 United Nations Environment Program report.

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