Lake Rukwa

Last updated
Lake Rukwa
Lake Rukwa.png
Lake Rukwa, as seen from space.
Lake Rukwa Basin OSM.png
Locationsouthwestern Tanzania
Coordinates 8°00′S32°25′E / 8.000°S 32.417°E / -8.000; 32.417 Coordinates: 8°00′S32°25′E / 8.000°S 32.417°E / -8.000; 32.417
Type alkaline
Catchment area 88,000 km2 (34,000 sq mi) [1]
Basin  countriesTanzania
Surface elevation800 metres (2,600 ft)

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

Contents

Geography

The alkaline Lake Rukwa lies midway between Lake Tanganyika and Lake Malawi at an elevation of about 800 metres (2,600 ft), in a parallel branch of the rift system. Almost half of the lake lies in Uwanda Game Reserve. [2]

Hydrology

The lake has seen large fluctuations in its size over the years, due to varying inflow of streams. Currently it is about 180 kilometres (110 mi) long and averages about 32 kilometres (20 mi) wide, making it about 5,760 square kilometres (2,220 sq mi) in size. [3] In 1929 it was only about 48 kilometres (30 mi) long, but in 1939 it was about 128 kilometres (80 mi) long and 40 kilometres (25 mi) wide. [4] During the early rifting of this part of Africa, the basin of Lake Rukwa may at times have been part of a much larger basin which also included the basins of Lake Tanganyika with Lake Malawi; ancient shorelines suggest a final date of overflow into Lake Tanganyika of 33,000BP. [5] For overflow to occur again, the lake's elevation would need to exceed 900 meters. Overflow into Lake Malawi is not possible now, since the pass between the two basin stands at over 2000 meters elevation. [6] (Neither Lake Tanganyika nor Lake Malawi can overflow into Lake Rukwa since they already overflow into the Atlantic and Indian Oceans respectively.)

There is an accumulation of selected heavy metals of Zinc, Mercury, Copper, Lead, Chromium and Nickel in sediment, water and muscle tissues of Clarias gariepinus (African catfish) and Oreochromis esculentus (Singida tilapia) fish was done in Lake Rukwa. [7]

Helium discovery

In 2016, an estimated 1.53 billion cubic meters (54.2 billion standard cubic feet) volume of helium gas was discovered in Lake Rukwa worth $3.5 billion. [8]

See also

Related Research Articles

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 Malawi African Great Lake

Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania.

Lake Tanganyika Lake in 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 Albert (Africa) lake in Uganda and the Democratic Republic of the Congo

Lake Albert, also Mwitanzige and formerly Lake Mobutu Sese Seko, is a lake located in Uganda and the Democratic Republic of the Congo. It is Africa's seventh largest lake, as well as the second biggest of Uganda's Great Lakes.

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.

African Great Lakes Series of lakes in the Rift Valley

The African Great Lakes are a series of lakes constituting the part of the Rift Valley lakes in and around the East African Rift. They include Lake Victoria, the third-largest fresh water lake in the world by area, Lake Tanganyika, the world's second-largest freshwater lake by volume and depth, and Lake Malawi, the world's eighth-largest fresh water lake by area. Collectively, they contain 31,000 km3 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 there.

Rift Valley lakes group of lakes in the East African Rift

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.

Lake Manyara salinity

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.

Luangwa River river in Zambia

The Luangwa River is one of the major tributaries of the Zambezi River, and one of the four biggest rivers of Zambia. The river generally floods in the rainy season and then falls considerably in the dry season. It is one of the biggest unaltered rivers in Southern Africa and the 20,000 square miles that make up the surrounding valley are home to abundant wildlife.

Ruzizi River River in Central Africa

The Ruzizi is a river, 117 kilometres (73 mi) long, that flows from Lake Kivu to Lake Tanganyika in Central Africa, descending from about 1,500 metres (4,900 ft) to about 770 metres (2,530 ft) above sea level over its length. The steepest gradients occur over the first 40 kilometres (25 mi), where hydroelectric dams have been built. Further downstream, the Ruzizi Plain, the floor of the Western Rift Valley, has only gentle hills, and the river flows into Lake Tanganyika through a delta, with one or two small channels splitting off from the main channel.

Kigoma Region Region in western, Tanzania

Kigoma Region is one of Tanzania's 31 administrative regions. The regional capital is the city of Kigoma. According to the 2012 national census, the region had a population of 2,127,930, which was higher than the pre-census projection of 1,971,332. For 2002-2012, the region's 2.4 percent average annual population growth rate was tied for the fourteenth highest in the country. It was also the sixteenth most densely populated region with 57 people per square kilometer. With a size of 45,066 square kilometres (17,400 sq mi), the region is slightly smaller than Estonia.

Mount Rungwe is a volcanic mountain in Mbeya Region, in Tanzania's Southern Highlands. At an altitude of 2,981 metres (9,780 ft), it is southern Tanzania's second highest peak. Rungwe's volcano is currently inactive.

Malagarasi River 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".

Southern Highlands, Tanzania mountain in Tanzania

The Southern Highlands is a highland region in southwestern Tanzania, at the northern end of Lake Malawi. The highlands include portions of Mbeya, Njombe, Rukwa, Ruvuma, and Songwe regions, bordering Malawi, Mozambique, and Zambia. Mbeya is the largest city in the highlands.

Rukwa Valley

The Rukwa Valley is a valley of southwestern Tanzania, and is a part of the Great Rift Valley. Sparsely populated because of its harsh environment, its grassland biodiversity includes thousands of species.

Congo-Nile Divide continental divide that separates the drainage basins of the Nile and Congo rivers

The Congo-Nile Divide is the continental divide that separates the drainage basins of the Nile and Congo rivers. It is about 2,000 kilometres (1,200 mi) long.

The geology of Malawi formed on extremely ancient crystalline basement rock, which was metamorphosed and intruded by igneous rocks during several orogeny mountain building events in the past one billion years. The rocks of the Karoo Supergroup and newer sedimentary units deposited across much of Malawi in the last 251 million years, in connection with a large rift basin on the supercontinent Gondwana and the more recent rifting that has created the East African Rift, which holds Lake Malawi. The country has extensive mineral reserves, many of them poorly understand or not exploited, including coal, vermiculite, rare earth elements and bauxite.

Geology of Tanzania overview about the geology of Tanzania

The geology of Tanzania began to form in the Precambrian, in the Archean and Proterozoic eons, in some cases more than 2.5 billion years ago. Igneous and metamorphic crystalline basement rock forms the Archean Tanzania Craton, which is surrounded by the Proterozoic Ubendian belt, Mozambique Belt and Karagwe-Ankole Belt. The region experienced downwarping of the crust during the Paleozoic and Mesozoic, as the massive Karoo Supergroup deposited. Within the past 100 million years, Tanzania has experienced marine sedimentary rock deposition along the coast and rift formation inland, which has produced large rift lakes. Tanzania has extensive, but poorly explored and exploited natural resources, including coal, gold, diamonds, graphite and clays.

The Ufipa Plateau is a highland in southwestern Tanzania. It lies mostly in Rukwa Region, near the border with Zambia. The plateau is named for the Fipa people who inhabit it.

References

  1. Lake Rukwa Bathymetry Survey Final Report 2014
  2. "Rukwa Uwanda Game Reserve". Utalii Travel and Safari. Retrieved 29 October 2010.
  3. Google Earth accessed 6 February 2007
  4. Encyclopædia Britannica Online/Lake Rukwa
  5. Lévêque, Christian (1997). Biodiversity Dynamics and Conservation: The Freshwater Fish of Tropical Africa. Cambridge University Press. p. 110.
  6. Google Maps
  7. Mapenzi, Levinus Leonard; Shimba, Moses Joel; Moto, Edward Angelo; Maghembe, Reuben Silas; Mmochi, Aviti John (January 2020). "Heavy metals bio-accumulation in tilapia and catfish species in Lake Rukwa ecosystem Tanzania". Journal of Geochemical Exploration. 208: 106413. doi: 10.1016/j.gexplo.2019.106413 . ISSN   0375-6742.
  8. "Helium 'could earn Tanzania $3.5bn'". www.thecitizen.co.tz. July 8, 2016.