Lakes are usually formed in rift zones, melting glaciated areas, mountainous regions, or in basins where rivers flow. On a geologic time scale, all lakes are transitory. Over time, lakes may run out of water caused by spillage or may be filled in with sediments. Although active processes may retard a lake from drying up such as lakes with tectonic origins. Some factors that causes lakes to form are landslides, sinkholes, ice-damming, volcanic eruptions, and glacier movements.
1. Lake Baikal - 5,387 feet
A UNESCO World Heritage Site, Lake Baikal in Russia is the deepest lake in the world. At 25 million years old, it is also the oldest lake in the world. Endemism occurs in the lake with half of its 60 native fish species and a freshwater seal. Baikal holds 20% of the world’s unfrozen freshwater, which amounts to around 5,662 cubic miles of crystal clear freshwater which is more than what the Great Lakes of North America holds in total volume.
2. Lake Tanganyika - 4,823 feet
Lake Tanganyika, at 4,823 feet, is the second deepest lake in the world. It is the world’s longest lake as well, with its span reaching into four countries, including Tanzania, the Democratic Republic of the Congo, Burundi, and Zambia. It holds around 18% of the world’s freshwater which is equal to close to 4,500 cubic miles of water. Tanganyika has six large islands and other smaller islands in its boundary. Its water has a pH of 8.4 that holds some 250 cichlid species, of which 98% are endemic. The cichlids exhibit adaptive and evolutionary radiation as well. Tanganyika has its own freshwater sardine species, jellyfish, and sponges.
3. Caspian Sea - 3,363 feet
The Caspian Sea at 3,363 feet is the third deepest lake in the world and bounded by Russia, Turkmenistan, Kazakhstan, Iran, and Azerbaijan. It holds around 18,800 cubic miles of water with 1.2% salinity although it has no connection to the ocean. It gets 80% of its water from the Volga River. The caviar producing Beluga sturgeon is found in the lake with tuna that has been the core of the fishing industry in the area. It has its own salmon and seal population. The areas around the lake and the lake itself has oil reserves of which some have been tapped.
4. Lake Vostok - 3,300 feet
Vostok Lake located in Antarctica is, at 3,300 feet, the fourth deepest lake in the world. It was named after the Russian Vostok Station which is close to it. It holds around 1,300 cubic miles of freshwater, 1,600 feet under the ice surface. Its water has a high concentration of oxygen and nitrogen that is under constant high pressure in total darkness. Microbial organisms have been detected in ice core drillings, while extremophile microbes found on frozen lake waters also suggest further presence of life. The lake is under protection by environmental groups who doubt the ice drilling methods being employed which could contaminate the lake water underneath the ice.
5. O'Higgins-San Martin Lake - 2,742
O'Higgins-San Martin Lake at 2,742 feet is the fifth deepest lake in the world, and its territory in Patagonia is shared by Chile and Argentina. Its name comes from two independence movement liberators from Chile. The lake is known as Lago O'Higgins in Chile and Lago San Martin in Argentina. Its shape forms finger-like extensions that end in flooded valleys in both countries. The Mayer River supplies most of its water while the Pascua River discharges its water into the Pacific Ocean.
6. Lake Malawi - 2,315
At 2,316 feet, Lake Malawi is the sixth deepest lake in the world, spanning the borders of Malawi, Mozambique (where it is known as Lago Niassa), and Tanzania (where it is known as Lake Nyasa). It has around 2,000 cubic miles of freshwater and is a meromictic lake whose water levels do not mix. Malawi hosts close to 1,000 cichlid fish species that continue to speciate, in addition to non-cichlid species. The Ruhuhu River provides most of its water while the Shire River discharges its water to the Zambezi River.
Limnology of Lakes
Lakes have three zones. These include the littoral zone near land, the photic zone in the open-water area where sunlight pervades, and the benthic zone housing deep-water lake habitats. A lake affects the temperature of its surrounding areas such as lowering the air temperature during the day while at night, air temperature may go up. Although lakes provide livelihood and food for the people living around it, some dangers are present when landslides and earthquakes cause the mixing of the benthic water to release carbon dioxide to the surface air. The released carbon dioxide could potentially flow into human inhabited regions and cause mass asphyxiation.
Deepest Lakes In The World
|Rank||Lake||Country||Depth (m)||Depth (ft)|
|2||Tanganyika||Tanzania, Democratic Republic of the Congo, Burundi, Zambia||1,470||4,823|
|3||Caspian Sea||Iran, Russia, Turkmenistan, Kazakhstan, Azerbaijan||1,025||3,363|
|5||O'Higgins-San Martín||Chile, Argentina||836||2,742|
|6||Malawi||Mozambique, Malawi, Tanzania||706||2,316|
|11||General Carrera-Buenos Aires||Chile, Argentina||586||1,923|
|18||Kivu||Democratic Republic of the Congo, Rwanda||480||1,575|
|23||Cochrane / Pueyrredón||Chile, Argentina||460||1,509|