Rift Valley lakes

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Rift Valley lakes
Lake Nakuru flamingos.jpg
Greater and lesser flamingos flock to Lake Nakuru in Kenya
LocationEast Africa
Type Series of lakes
Map of larger region that the lakes are in, including the so-called Great Rift Valley. MapGreatRiftValley.png
Map of larger region that the lakes are in, including the so-called Great Rift Valley.
View over Lake Turkana Lake turkana.jpg
View over Lake Turkana

The Rift Valley lakes are a series of lakes in the East African Rift valley that runs through eastern Africa from Ethiopia in the north to Malawi in the south, and includes the African Great Lakes in the south. These include some of the world's oldest lakes, deepest lakes, largest lakes by area, and largest lakes by volume. Many are freshwater ecoregions of great biodiversity, while others are alkaline "soda lakes" supporting highly specialised organisms.

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The Rift Valley lakes are well known for the evolution of at least 800 cichlid fish species that live in their waters. More species are expected to be discovered. [1]

The World Wide Fund for Nature has designated these lakes as one of its Global 200 priority ecoregions for conservation.[ citation needed ]

In this article, the major lakes are listed, generally in order from north to south, and more detailed articles on each lake can be accessed through the linked names.

Geology

Lake Malawi and Lake Tanganyika have formed in the various valleys of the East African Rift zone.

Ecology

Lake Kivu's "still waters ... hide another face: dissolved within are billions of cubic meters of flammable methane and more still of carbon dioxide, the result of volcanic gases seeping in." [2]

Ethiopian Rift Valley lakes

Ethiopia central lakes.jpg

The Ethiopian Rift Valley lakes are the northernmost of the African Rift Valley lakes. In central Ethiopia, the Main Ethiopian Rift, also known as the Great Rift Valley, splits the Ethiopian highlands into northern and southern halves, and the Ethiopian Rift Valley lakes occupy the floor of the rift valley between the two highlands. Most of the Ethiopian Rift Valley lakes do not have an outlet, and most are alkaline. Although the Ethiopian Rift Valley lakes are of great importance to Ethiopia's economy, as well as being essential to the survival of the local people, there were no intensive and extensive limnological studies undertaken of these lakes until recently. [3]

The major ones are

Lake Tana, the source of the Blue Nile, lies in the Ethiopian highlands north of the Rift Valley; however, it is not a Rift Valley lake. [4]

Eastern Rift Valley lakes

Lake Natron Lago natron.PNG
Lake Natron

South of the Ethiopian highlands, the rift valley splits into two major troughs. The Eastern Rift is home to the Kenyan Rift Valley lakes, while most of the Central African Rift Valley lakes lie in the Western Rift. This area includes the Gregory Rift in Kenya and Tanzania.

Kenya

The Kenyan section of the Rift Valley is home to eight lakes, of which three are freshwater and the rest alkaline. Of the latter, the shallow soda lakes of the Eastern Rift Valley have crystallised salt turning the shores white and are famous for the large flocks of flamingo that feed on crustaceans.

Tanzania

All the lakes in the Tanzanian section of this group are alkaline:

Western or Albertine Rift Valley lakes

Map of Great Rift Valley.svg
Some of the Rift Valley lakes. From left to right they are Lake Upemba, Lake Mweru, Lake Tanganyika (largest), and Lake Rukwa. This image spans the SE corner of the Democratic Republic of the Congo, NE Zambia, and southern Tanzania. NASA - Visible Earth, Lakes of the African Rift Valley.jpg
Some of the Rift Valley lakes. From left to right they are Lake Upemba, Lake Mweru, Lake Tanganyika (largest), and Lake Rukwa. This image spans the SE corner of the Democratic Republic of the Congo, NE Zambia, and southern Tanzania.

The lakes of the Western or Albertine Rift, with Lake Victoria, include the largest, deepest, and oldest of the Rift Valley Lakes. They are also referred to as the Central African lakes. Lakes Albert, Victoria, and Edward are part of the Nile River basin.

Lake Victoria (elevation 1,134 metres (3,720 ft)), with an area of 68,800 square kilometres (26,600 sq mi), is the largest lake in Africa. It is not in the rift valley, instead occupying a depression between the eastern and western rifts formed by the uplift of the rifts to either side. Lakes Victoria, Tanganyika, and Malawi are sometimes collectively known as the African Great Lakes.

The Western Rift Valley lakes are fresh water and home to an extraordinary number of species. Approximately 1,500 cichlid fish (Cichlidae) species live in the lakes. In addition to the cichlids, populations of Clariidae, Claroteidae, Mochokidae, Poeciliidae, Mastacembelidae, Centropomidae, Cyprinidae, Clupeidae and other fish families are found in these lakes. They are also important habitats for a number of amphibian species, including Amietophrynus kisoloensis , Bufo keringyagae , Cardioglossa cyaneospila , and Nectophryne batesii .

Southern Rift Valley lakes (Tanzania and Malawi)

The Southern Rift Valley lakes are like the Western Rift Valley lakes in that, with one exception, they are freshwater lakes.

Other lakes of the Great Rift Valley

Related Research Articles

Geography of Africa Geographical features of Africa

Africa is a continent comprising 63 political territories, representing the largest of the great southward projections from the main mass of Earth's surface. Within its regular outline, it comprises an area of 30,368,609 km2 (11,725,385 sq mi), excluding adjacent islands. Its highest mountain is Mount Kilimanjaro, its largest lake is Lake Victoria.

The Democratic Republic of the Congo (DRC) is the largest country of sub-Saharan Africa, occupying some 2,344,858 square kilometres (905,355 sq mi). Most of the country lies within the vast hollow of the Congo River basin. The vast, low-lying central area is a plateau-shaped basin sloping toward the west, covered by tropical rainforest and criss-crossed by rivers. The forest center is surrounded by mountainous terraces in the west, plateaus merging into savannas in the south and southwest. Dense grasslands extend beyond the Congo River in the north. High mountains of the Ruwenzori Range are found on the eastern borders with Rwanda and Uganda.

Great Rift Valley Continuous geographic trench

The Great Rift Valley is a series of contiguous geographic trenches, approximately 7,000 kilometres (4,300 mi) in total length, that runs from the Beqaa Valley in Lebanon which is in Asia to Mozambique in Southeast Africa. While the name continues in some usages, it is rarely used in geology as it is considered an imprecise merging of separate though related rift and fault systems.

Geography of Tanzania

Tanzania comprises many lakes, national parks, and Africa's highest point, Mount Kilimanjaro. Northeast Tanzania is mountainous, while the central area is part of a large plateau covered in grasslands. The country also contains the southern portion of Lake Victoria on its northern border with Uganda and Kenya.

Lake Tanganyika Rift lake in east-central Africa

Lake Tanganyika is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. The lake is shared between four countries—Tanzania, the Democratic Republic of the Congo (DRC), Burundi, and Zambia, with Tanzania (46%) and DRC (40%) possessing the majority of the lake. It drains into the Congo River system and ultimately into the Atlantic Ocean.

Lake Mweru Lake in Zambia

Lake Mweru is a freshwater lake on the longest arm of Africa's second-longest river, the Congo. Located on the border between Zambia and Democratic Republic of the Congo, it makes up 110 kilometres (68 mi) of the total length of the Congo, lying between its Luapula River (upstream) and Luvua River (downstream) segments.

Lake Natron

Lake Natron is a salt or alkaline lake in Arusha Region in Tanzania. It is in the Gregory Rift, which is the eastern branch of the East African Rift. The lake is within the Lake Natron Basin, a Ramsar Site wetland of international significance.

Lake Kivu Meromictic lake in the East African Rift valley

Lake Kivu is one of the African Great Lakes. It lies on the border between the Democratic Republic of the Congo and Rwanda, and is in the Albertine Rift, the western branch of the East African Rift. Lake Kivu empties into the Ruzizi River, which flows southwards into Lake Tanganyika.

Lake Naivasha it a town now occupied with many tribes

Lake Naivasha is a freshwater lake in Kenya, outside the town of Naivasha in Nakuru County, which lies north west of Nairobi. It is part of the Great Rift Valley. The name derives from the local Maasai name Nai'posha, meaning "rough water" because of the sudden storms which can arise.

Luapula River

The Luapula River is a section of Africa's second-longest river, the Congo. It is a transnational river forming for nearly all its length part of the border between Zambia and the DR Congo. It joins Lake Bangweulu to Lake Mweru and gives its name to the Luapula Province of Zambia.

Lake Manyara

Lake Manyara is the seventh-largest lake of Tanzania by surface area, at 470-square-kilometre (180 sq mi). It is a shallow, alkaline lake in the Natron-Manyara-Balangida branch of the East African Rift in Manyara Region in Tanzania. The northwest quadrant of the lake is included within Lake Manyara National Park and it is part of the Lake Manyara Biosphere Reserve, established in 1981 by UNESCO as part of its Man and the Biosphere Programme.

Lake Rukwa Lake in Tanzania

Lake Rukwa is an endorheic lake in the Rukwa Valley of southwestern Tanzania.

Lake Shala

Lake Shala is an alkaline lake located in the Ethiopian Rift Valley, in the Abijatta-Shalla National Park.

Malagarasi River

The Malagarasi River is a river in western Tanzania, flowing through Kigoma Region, although one of its tributaries comes from southeastern Burundi. It is the second-longest river in Tanzania behind the Rufiji—Great Ruaha, and has the largest watershed of any river flowing into Lake Tanganyika. The Malagarasi-Muyovozi Wetlands are a designated a Ramsar site. Local tribes have nicknamed the Malagarasi as "the river of bad spirits".

Lake large body of relatively still water

A lake is an area filled with water, localized in a basin, surrounded by land, apart from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although like the much larger oceans, they form part of earth's water cycle. Lakes are distinct from lagoons which are generally coastal parts of the ocean. They are generally larger and deeper than ponds, which also lie on land, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which are usually flowing in a channel on land. Most lakes are fed and drained by rivers and streams.

Shijiu Lake Lake in eastern Chinas Anhui and Jiangsu provinces

Shijiu Lake(Chinese: 石臼湖; pinyin: Shíjiù Hú) is a freshwater lake in eastern China, situated at the lower reaches of the Yangtze River. One half of the lake that is to the west, belongs to the Dangtu County of Anhui Province and the other part lies in the Gaochun and Lishui Districts of Nanjing, Jiangsu Province.

Wabu Lake

Wabu Lake(Chinese: 瓦埠湖; pinyin: Wǎbù Hú) is a freshwater lake in China, it is located in the center of Anhui Province, situated in the south bank of the middle reaches of the Huai River.

Nanyi Lake

Nanyi Lake(Chinese: 南漪湖; pinyin: Nányī Hú) is a freshwater lake in China, it is situated in south of Anhui Province, between Xuanzhou District and Langxi County. The area of the watershed is 3,368.7 square kilometres (1,300.7 sq mi), with an elevation of 9.38 metres (30.8 ft), its length is 26 kilometres (16 mi) and the greatest breadth from east to west is 8.4 kilometres (5 mi). The surface is equal to 148.4 square kilometres (100 sq mi), and volume is about 334 million cubic metres. The maximum depth of the Nanyi Lake is 3.25 metres (11 ft), and the average being 2.25 metres (7 ft).

Great Rift Valley, Ethiopia

The Great Rift Valley of Ethiopia, is a branch of the East African Rift that runs through Ethiopia in a southwest direction from the Afar Triple Junction. In the past, it was seen as part of a "Great Rift Valley" that ran from Mozambique to Syria.

Great Rift Valley, Kenya Part of an intra-continental ridge system that runs through Kenya

The Great Rift Valley is part of an intra-continental ridge system that runs through Kenya from north to south. It is part of the Gregory Rift, the eastern branch of the East African Rift, which starts in Tanzania to the south and continues northward into Ethiopia. It was formed on the "Kenyan Dome" a geographical upwelling created by the interactions of three major tectonics: the Arabian, Nubian, and Somalian plates. In the past, it was seen as part of a "Great Rift Valley" that ran from Madagascar to Syria. Most of the valley falls within the former Rift Valley Province.

References

  1. 1 2 "WWF Global 200 Ecoregions – Rift Valley Lakes (182)". www.worldwildlife.org. Archived from the original on December 22, 2004. Retrieved 16 March 2008.
  2. "What Lies Beneath". The Economist. 2016-03-12.
  3. Hynes, H. B. N. "Tudorancea, C. & Taylor W.D. (Eds) Ethiopian Rift Valley Lakes". www.euronet.nl. Retrieved 16 March 2008.
  4. 1 2 Smith, Anthony (1988). The Great Rift: Africa's Changing Valley . London: BBC Books. ISBN   978-0-8069-6906-0.
  5. Plisnier P.-D., Chitamwebwa D., Mwape L., Tshibangu K., Langenberg V., Coenen E. (1999). "Limnological annual cycle inferred from physical-chemical fluctuations at three stations of Lake Tanganyika". Hydrobiologia. 407: 45–58. doi:10.1023/A:1003762119873.CS1 maint: multiple names: authors list (link)
  6. Bos AR, CK Kapasa and PAM van Zwieten (2006). "Update on the bathymetry of Lake Mweru (Zambia), with notes on water level fluctuations". African Journal of Aquatic Science. 31 (1): 145–150. doi:10.2989/16085910609503882.