Rift Valley lakes | |
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![]() Greater and lesser flamingos flock to Lake Nakuru in Kenya | |
Location | East Africa |
Coordinates | 3°00′N36°20′E / 3.000°N 36.333°E |
Type | Series of lakes |
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.
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 ]
Lake Malawi and Lake Tanganyika have formed in the various valleys of the East African Rift zone. 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]
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]
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.
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.
All the lakes in the Tanzanian section of this group are alkaline:
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 .
The Southern Rift Valley lakes are like the Western Rift Valley lakes in that, with one exception, they are freshwater lakes.
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 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.
The Great Rift Valley is a series of contiguous geographic depressions, approximately 6,000 or 7,000 kilometres (4,300 mi) in total length, the definition varying between sources, that runs from the southern Turkish Hatay Province in Asia, through the Red Sea, 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.
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 is an African Great Lake. It is the second-largest freshwater lake by volume and the second deepest, in both cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. The lake is shared among four countries—Tanzania, the Democratic Republic of the Congo, Burundi, and Zambia—with Tanzania (46%) and the DRC (40%) possessing the majority of the lake. It drains into the Congo River system and ultimately into the Atlantic Ocean.
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 is a salt or alkaline lake located in north Ngorongoro District of Arusha Region in Tanzania at the border with Kenya. 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. It is the only regular breeding area for Africa's lesser flamingoes, although this habitat is not protected and is under threat from planned development projects.
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. In 1894, German officer and colonial ruler Gustav Adolf von Götzen was the first European to discover the lake.
Lake Naivasha is a freshwater lake in Kenya, outside the town of Naivasha in Nakuru County, which lies north west of Nairobi. It is situated in the Great Rift Valley. The name derives from the local Maasai name ɛnaɨpɔ́sha , meaning "that which heaves," a common Maasai word for bodies of water large enough to have wave action when it is windy or stormy. Naivasha arose from a British attempt to pronounce the Maasai name. Literally, Lake Naivasha means "Lake Lake."
The African Great Lakes are a series of lakes constituting the part of the Rift Valley lakes in and around the East African Rift. The series includes Lake Victoria, the second-largest freshwater lake in the world by area; Lake Tanganyika, the world's second-largest freshwater lake by volume and depth; Lake Malawi, the world's eighth-largest freshwater lake by area; and Lake Turkana, the world's largest permanent desert lake and the world's largest alkaline lake. Collectively, they contain 31,000 km3 (7,400 cu mi) of water, which is more than either Lake Baikal or the North American Great Lakes. This total constitutes about 25% of the planet's unfrozen surface fresh water. The large rift lakes of Africa are the ancient home of great biodiversity, and 10% of the world's fish species live in this region.
The Luapula River is a north-flowing river of central Africa, within the Congo River watershed. It rises in the wetlands of Lake Bangweulu (Zambia), which are fed by the Chambeshi River. The Luapula flows west then north, marking the border between Zambia and the Democratic Republic of the Congo before emptying into Lake Mweru. The river gives its name to Zambia's Luapula Province.
Lake Bogoria is a saline, alkaline lake that lies in a volcanic region in a half-graben basin south of Lake Baringo, Kenya, a little north of the equator. Lake Bogoria, like Lake Nakuru, Lake Elementeita, and Lake Magadi further south in the Rift Valley, and Lake Logipi to the north, is periodically home to one of the world's largest populations of lesser flamingos. The lake is a Ramsar site and Lake Bogoria National Reserve has been a protected National Reserve since November 29, 1973.
Lake Rukwa is an endorheic lake located the Rukwa Valley of Rukwa Region, Songwe Region and Katavi Region in southwestern Tanzania. The lake is the third largest inland body of water in the country.
Lake Nakuru is one of the Rift Valley lakes, located at an elevation of 1,754 m (5,755 ft) above sea level. It lies to the south of Nakuru, in the rift valley of Kenya and is protected by Lake Nakuru National Park.
Lake Shala is an alkaline lake located in the Ethiopian Rift Valley, in the Abijatta-Shalla National Park.
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. Known for its scenery and diverse wildlife in Ethiopia specifically the Rift Valley holds importance in the field of human evolution. It is recognized as an area for researching the stages of human development with crucial fossil findings such, as Lucy unearthed within its bounds.
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.
The Gregory Rift is the eastern branch of the East African Rift fracture system. The rift is being caused by the separation of the Somali Plate from the Nubian Plate, driven by a thermal plume. Although the term is sometimes used in the narrow sense of the Kenyan Rift, the larger definition of the Gregory Rift is the set of faults and grabens extending southward from the Gulf of Aden through Ethiopia and Kenya into Northern Tanzania, passing over the local uplifts of the Ethiopian and Kenyan domes. Ancient fossils of early hominins, the ancestors of humans, have been found in the southern part of the Gregory Rift.
The Olkaria Area is a region located immediately to the south of Lake Naivasha in the Great Rift Valley of Kenya, Africa. It is geothermally active and is being used to generate clean electric power. The region has an estimated potential of 2,000 MW. This is almost double the maximum daily electricity peak demand recorded in 2008/2009 for the entire country.
Lake Suguta is a former lake in Africa. It formed in the Suguta Valley, which is part of the East African Rift, south of Lake Turkana during the Holocene African humid period.
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