An endorheic lake is also called a terminal lake or a sink lake. It is a lake that has no outlet. These lakes are usually saltwater lakes because the minerals left in the lake by evaporation have nowhere else to go. The salt level builds up over many years.
There are also cryptoheic lakes. These lakes have drainage below the surface that may not be visible to the naked eye. They typically drain to nearby swamps or marshes.
Endorheic lakes collect water and form from rainfall or river flow. The water only leaves the lake through evaporation or sinking underground, forming an aquifer.
What is the Largest Endorheic Lake on Earth?
The Caspian Sea is the largest endorheic lake, despite its name. It is also the largest body of water in an inland setting and the world’s largest lake. At over 140,000 square miles, it sits between Europe and Asia. It is about 750 miles long and an average of 200 miles wide. Its depth ranges from 16 feet to over 3,000 feet. The Caspian Sea is surrounded by the countries Azerbaijan, Russia, Kazakhstan, Turkmenistan, and Iran. This sea is primarily formed by over 130 rivers that empty into it, the largest being the Volga River which flows from Russia. The Caspian Sea only loses water through evaporation.
As it is so large and made up of salt water, many ancient cultures thought it was an ocean. In modern times, the Caspian Sea has become an important political location due to its abundance of oil and natural gas. It is estimated that there is more than $12 trillion of oil in the Caspian Sea.
What Is The Second-Largest Endorheic Lake on Earth?
Lake Balkhash in Kazakstan is the second-largest terminal lake in the world. It is the 15th largest lake in the world. It is fed mainly by the Ili River which flows through China and Kazakstan and six other rivers in the area. One thing that makes Lake Balkhash unique is that the Western part of the lake is freshwater while the Eastern part is saltwater. This lake is more than 6,000 square miles. However, it has a problem that several other endorheic lakes are also facing. It is actually shrinking due to human activities; primarily water extraction from the rivers that feed it. Experts worry that the area could face desertification in the future—meaning the area could develop a more desert-like climate due to too much water extraction. As recently as 1910 the lake covered at least 9,000 square miles.
Other Large Endorheic Lakes
Even though Lake Eyre only exists some of the time, it is often considered the third-largest endorheic lake in the world. It is a shallow lake and is the lowest point in Australia. When the lake is full, which only happens rarely, it is the largest lake in Australia and spans over 3,500 square miles. When it is full it has the same salt level as the ocean. However, as the water evaporates the salinity increases. The lake usually fills during the rainy season as the rivers that feed it become more full. Then, throughout the rest of the year, the water evaporates leaving behind a salt crust and shallow areas of pink water that are colored by the presence of algae.
Lake Turkana in Kenya and Ethiopia is the world’s largest permanent desert lake. It is also the largest alkaline lake, meaning it is more basic than acidic. It is the fourth-largest endorheic lake in the world. This lake looks like something from another planet. It has very few plants around it and is surrounded by lava beds. In the middle of the lake is an active volcano. The area is full of dangerous critters like crocodiles, scorpions, and dangerous snakes.
This lake is unique in that it is only slightly salty, but has a high level of fluoride that makes it unsuitable for drinking. The level of fluoride is much higher than what we add to our drinking water to improve dental health. However, like many lakes, endorheic or not, it is threatened by climate change and human activity. A dam on the Omo River in Ethiopia has caused the lake level to lower as that river supplied most of the lake’s water. Because the lake’s only source of outflow is evaporation, the lake’s levels are also variable depending on current weather conditions.
Issyk-Kul is an endorheic lake in Kyrgystan. It spans about 2,400 square miles. Even though is it located in the Tian Shan Mountains, and is surrounded by snowy peaks, the lake doesn’t due to its salinity. Experts believe this lake’s levels have risen more than 25 feet since medieval times. They have found remains of settlements in shallower areas of the lake. They even found a 2,500 settlement deeper in the lake in 2007. The name Issyk-Kul means “warm lake”. Although the water temperature is not warm, it got that name because it never freezes.
Lake Urmia, located in Iran, is often considered the sixth-largest endorheic lake in the world, but it is shrinking. It once had a surface area of 2,000 square miles. However, experts believe it had shrunk by up to 10% in 2017, and they believe it only holds 1/60 of its original volume. They believe these changes are due to drought in Iran, and because many of the rivers that feed the lake have been dammed. However, in more recent years, increased rain and conservation efforts, including diverting water towards the lake, have caused it to refill again.
This is the seventh-largest endorheic lake in the world and the largest lake in China. While this lake was shrinking for much of the 20th century, it actually started increasing in size in 2004. This saltwater lake often freezes for three months in the winter. The lake has been important in local culture. There is an island on the lake with a Buddhist monastery. In the past, monks would only travel there in the winter over the frozen lake surface and would not leave until the lake froze again.
The Great Salt Lake
The Great Salt Lake, from which Salt Lake City in Utah gets its name, is the largest salt lake in the western hemisphere. It is also the eighth-largest salt lake in the world. It is large enough to cause lake-effect snow in the area. The lake reached its highest level of 3300 square miles in the 1980s. This caused the development of a project to pump excess water into the nearby desert to prevent flooding. However, in 2021, the lake reached its lowest level ever and remains around just 950 square miles. If the lake gets too small, experts worry that it could lead to clouds of dust that may make the air in and around Salt Lake City toxic. This lake is much saltier than the ocean, and thus if you swim in it, you will have an easier time floating, similar to the Dead Sea.
FAQs (Frequently Asked Questions)
What is an endorheic lake?
An endorheic lake is a lake that has no outlet. These lakes are usually saltwater because the minerals left in the lake have nowhere else to go. In other types of lakes minerals are swept away by flowing water.
Endorheic lakes generally collect water and form from rainfall or river flow. The water only leaves the lake through evaporation or sinking underground, forming an aquifer.
What is the largest endorheic lake on earth?
The Caspian Sea is the largest endorheic lake in the world.
How large is the Caspian Sea?
The Caspian Sea covers 143,555 square miles. It is about 750 miles long and an average of 200 miles wide. The lake’s depth ranges from 16 feet to over 3,000 feet.
Which countries surround the Caspian Sea?
The Caspian Sea is surrounded by the countries Azerbaijan, Russia, Kazakhstan, Turkmenistan, and Iran.
What is the second largest endorheic lake on earth?
Lake Balkhash in Kazakstan is the second-largest terminal lake in the world. It is the 15th-largest lake in the world.