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50-665: In the past, Lake Kivu drained toward the north, contributing to the White Nile . About 13,000 to 9,000 years ago, volcanic activity blocked Lake Kivu's outlet to the watershed of the Nile. The volcanism produced mountains, including the Virungas , which rose between Lake Kivu and Lake Edward, to the north. Water from Lake Kivu was then forced south down the Ruzizi. This, in turn, raised the level of Lake Tanganyika , which overflowed down

100-675: A rift valley that is slowly being pulled apart, causing volcanic activity in the area. The world's tenth-largest island in a lake , Idjwi , lies in Lake Kivu. Settlements on the lake's shore include Bukavu , Kabare , Kalehe , Sake and Goma in the Democratic Republic of the Congo, and Gisenyi , Kibuye , and Cyangugu in Rwanda. Lake Kivu is a fresh water lake and, along with Cameroonian Lake Nyos and Lake Monoun ,

150-458: A chance of suffering a limnic eruption every 1000 years. The lake has a maximum depth of 475 m (1,558 ft) and a mean depth of 220 m (722 ft), making it the world's twentieth deepest lake by maximum depth, and the thirteenth deepest by mean depth. Some 1,370 square kilometres (529 sq mi) or 58 percent of the lake's waters lie within DRC borders. The lake bed sits upon

200-635: A depth of 300 metres (1,000 ft). Until 2004, extraction of the gas was done on a small scale, with the extracted gas being used to run boilers at the Bralirwa brewery in Gisenyi . As far as large-scale exploitation of this resource is concerned, the Rwandan government has negotiated with a number of parties to produce methane from the lake. In 2011 ContourGlobal , a UK-based energy company focused on emerging markets, secured project financing to initiate

250-576: A further 25 MW and are currently negotiating a PPA with the Rwanda Electricity Group which may see 8 MW of power despatched to the Grid six months after the PPA has been signed. This concession is on the site of the original pilot plant known as KP1. In addition to managing gas extraction, KivuWatt will also manage the electrical generation plants and on-sell the electrical power to

300-467: A lake much older than the commonly cited 15,000 years. Lake Kivu is the home of four species of freshwater crab , including two non-endemics ( Potamonautes lirrangensis and P. mutandensis ) and two endemics ( P. bourgaultae and P. idjwiensis ). Among Rift Valley lakes , Lake Tanganyika and Lake Victoria are the only other with endemic freshwater crabs. In 2018, over 400 cases of potential illegal fishing were recorded on Lake Kivu. According to

350-413: A large-scale methane extraction project. The project is run through a local Rwandan entity called KivuWatt , using an offshore barge platform to extract, separate, and clean the gasses obtained from the lake bed before pumping purified methane via an underwater pipeline to on-shore gas engines . Stage one of the project, powering three " gensets " along the lake shore and supplying 26 MW of electricity to

400-685: A larger project, which the Ugandans will fund internally if necessary. Just before entering Lake Albert, the river is compressed into a passage just seven meters wide at Murchison Falls , marking its entry into the western branch of the East African Rift . The river then flows into Lake Albert opposite the Blue Mountains in the Democratic Republic of the Congo . The stretch of river from Lake Kyoga to Lake Albert

450-449: A nucleation-controlled reaction like spherulitic growth . Recent studies have highlighted the importance of Mg in the formation process of monohydrocalcite. The presence of Mg in solution is known to inhibit the formation of vaterite and calcite . However, the hydrated nature of monohydrocalcite means that full dehydration of Mg is not required before incorporation of this ion into this mineral and therefore it will more likely form than

500-574: Is frequently associated with other calcium and magnesium carbonate minerals , such as calcite , aragonite , lansfordite , and nesquehonite . Monohydrocalcite has been observed in air conditioning systems , and in moonmilk deposits in caves, both probably formed from spray of carbonate rich fluids. It is well known in Robe on the Limestone Coast of South Australia as a component of beach sands of Lake Fellmongery and Lake Butler, where it

550-501: Is 0.71 g C m d (≈ 260 g C m a). A study of evolutionary genetics showed that the cichlids from lakes in northern Virunga (e.g., Edward , George , Victoria ) would have evolved in a "proto-lake Kivu", much older than the intense volcanic activity (20,000-25,000 years ago) which cut the connection. The elevation of the mountains west of the lake (which is currently the Kahuzi-Biega National Park , one of

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600-403: Is approximately 42 km (26 mi) long and 50 km (31 mi) at its widest. Its irregular shape makes measuring its precise surface area difficult; it has been estimated to cover a total surface area of some 2,700 km (1,040 sq mi), making it Africa's eighth largest lake. The surface of the lake sits at a height of 1,460 metres (4,790 ft) above sea level. This lake has

650-463: Is believed to be formed from algal spume. Other lacustrine deposits include Lake Issyk-Kul , Kyrgyzstan , Lake Kivu , Democratic Republic of the Congo , and Solar Lake , Sinai . It has been reported as a significant component of the decomposition of ikaite in the towers of the Ikka Fjord, West Greenland . It is also noted for its bizarre occurrences, which include inside the otoliths of

700-429: Is equivalent to the power output of six Grand Coulee Dams operating at peak springtime power. The lake also holds an estimated 256 cubic kilometres (61 cu mi) of carbon dioxide which, if released in an eruption event, could suffocate all of the inhabitants of the lakeshore. The water temperature is 24 °C (75 °F), and the pH is about 8.6. The methane is reported to be produced by microbial reduction of

750-458: Is one of three that are known to undergo limnic eruptions (where overturn of deepwater stratified layers releases dissolved carbon dioxide). Around the lake, geologists found evidence of massive local extinctions about every thousand years, presumably caused by outgassing events. The trigger for lake overturns in Lake Kivu is unknown, but volcanic activity and changes in climate are both suspected. The gaseous chemical composition of exploding lakes

800-580: Is sometimes called the "Kyoga Nile". The river draining from Lake Albert to the north is called the "Albert Nile". It separates the West Nile sub-region of Uganda from the rest of the country. A bridge passes over the Albert Nile near its inlet in Nebbi District , but no other bridge over this section has been built. A ferry connects the roads between Adjumani and Moyo , and navigation of

850-763: Is the longest tributary of the Kagera, and hence the most distant source of the Nile . The source of the Nile can be considered to be either the Ruvyironza , which emerges in Bururi Province , Burundi (near Bukirasaz), or the Nyabarongo , which flows from Nyungwe Forest in Rwanda. These two feeder rivers meet near Rusumo Falls on the border between Rwanda and Tanzania. These waterfalls are known for an event on 28–29 April 1994, when 250,000 Rwandans crossed

900-445: Is unique to each lake. In Lake Kivu's case, it includes methane ( CH 4 ) and carbon dioxide (CO 2 ), as a result of lake water interaction with volcanic hot springs. The amount of methane contained at the bottom of the lake is estimated to be 65 cubic kilometres (16 cu mi). If burned in a modern combined-cycle generating plant , that amount of methane would generate around 40,000 megawatts for an entire year, which

950-471: The Lukuga River . Lake Kivu is one of three lakes in the world, along with Lake Nyos and Lake Monoun , that undergo limnic eruptions (where overturn of deepwater stratified layers releases dissolved carbon dioxide (CO 2 )). The lake's bottom also contains methane ( CH 4 ), meaning if a limnic eruption occurs, the lives of the two million people living nearby would be in danger. Lake Kivu

1000-634: The Scramble for Africa . In Sudan the river lends its name to the Sudanese state of White Nile , before merging with the larger Blue Nile at Khartoum and forming the River Nile. The White Nile is a navigable waterway from the Lake Albert to Khartoum through Jebel Aulia Dam , only between Juba and Uganda requires the river upgrade or channel to make it navigable. During part of the year

1050-602: The confluence of the Bahr al Jabal and Bahr el Ghazal Rivers. In the wider sense, "White Nile" refers to all the stretches of river draining from Lake Victoria through to the merger with the Blue Nile: the "Victoria Nile" from Lake Victoria via Lake Kyoga to Lake Albert , then the "Albert Nile" to the South Sudan border, and then the "Mountain Nile" or "Bahr-al-Jabal" down to Lake No. "White Nile" may sometimes include

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1100-500: The tiger shark , the bladder of a guinea pig , the calcareous corpuscles of a cestode parasite, and the final stages of decomposition of the putrefying flesh of the giant saguaro cactus . These occurrences suggest a biochemical origin is possible. Monohydrocalcite forms via a Mg-rich amorphous calcium carbonate (ACC) precursor. This Mg-rich ACC forms rapidly (seconds) and then transforms to monohydrocalcite via dissolution and reprecipitation, with monohydrocalcite forming via

1150-698: The "Albert Nile" from there to the border with South Sudan. The Victoria Nile starts at the outlet of Lake Victoria, at Jinja, Uganda , on the northern shore of the lake. Downstream from the Nalubaale Power Station and the Kiira Power Station at the outlet of the lake, the river goes over Bujagali Falls (the location of the Bujagali Power Station ) about 15 km (9.3 mi) downstream from Jinja. The river then flows northwest through Uganda to Lake Kyoga in

1200-638: The Animal Research and Technology Transfer at the Rwanda Agricultural Board, fish production in Kivu Lake dropped from 24 199 tonnes in the 2017–2018 fishing season to 16 194 tonnes in 2019–2020, which Deputy Director Solange Uwituze attributed to fishing methods that affect fish reproduction. Between May and July 2020, Rwanda Police Marine Unit operations reported 27 cases including 10 arrested poachers for illegal fishing on

1250-716: The Bahr el Ghazal and there forms the White Nile. An anabranch river called Bahr el Zeraf flows out of the Bahr al-Jabal at and flows through the Sudd, to eventually join the White Nile. The Mountain Nile cascades through narrow gorges and over a series of rapids that includes the Fula (Fola) Rapids. To some people, the White Nile starts at the confluence of the Mountain Nile with the Bahr el Ghazal at Lake No. The 120 kilometers of White Nile that flow east from Lake No to

1300-429: The Rwandan government under the terms of a long-term Power Purchase Agreement (PPA). This allows KivuWatt to control a vertically integrated energy offering from point of extraction to point of sale into the local grid. Extraction is said to be cost-effective and relatively simple because once the gas-rich water is pumped up, the dissolved gases (primarily carbon dioxide, hydrogen sulphide and methane) begin to bubble out as

1350-626: The bridge at Rusumo Falls into Ngara , Tanzania , in 24 hours, in what the United Nations High Commissioner for Refugees called "the largest and fastest refugee exodus in modern times". The Kagera forms part of the Rwanda–Tanzania and Tanzania–Uganda borders before flowing into Lake Victoria. The White Nile in Uganda goes under the name of "Victoria Nile" from Lake Victoria via Lake Kyoga to Lake Albert, and then as

1400-449: The centre of the country, thence west to Lake Albert. At Karuma Falls , the river flows under Karuma Bridge ( 2°14′45.40″N 32°15′9.05″E  /  2.2459444°N 32.2525139°E  / 2.2459444; 32.2525139 ) at the southeastern corner of Murchison Falls National Park . During much of the insurgency of the Lord's Resistance Army , Karuma Bridge, built in 1963 to help

1450-441: The cotton industry, was the key stop on the way to Gulu , where vehicles gathered in convoys before being provided with a military escort for the final run north. In 2009, the government of Uganda announced plans to construct a 750-megawatt hydropower project several kilometres north of the bridge, which was scheduled for completion in 2016. The World Bank had approved funding a smaller 200-megawatt power plant, but Uganda opted for

1500-586: The headwaters of Lake Victoria, the most remote of which being 3,700 km (2,300 mi) from the Blue Nile. The 19th-century search by Europeans for the source of the Nile was mainly focused on the White Nile, which disappeared into the depths of what was then known as "Darkest Africa". The Kagera River , which flows into Lake Victoria near the Tanzanian town of Bukoba , is the longest feeder river for Lake Victoria, although sources do not agree on which

1550-438: The lake surface. It is also possible that the lake could spawn lake tsunamis as gas explodes out of it. The risk posed by Lake Kivu began to be understood during the analysis of more recent events at Lake Nyos. Lake Kivu's methane was originally thought to be merely a cheap natural resource for export, and for the generation of cheap power. Once the mechanisms that caused lake overturns began to be understood, so did awareness of

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1600-456: The lake's bottom water that has high gas concentrations would heat water, force the methane out of the water, spark a methane explosion, and trigger a nearly simultaneous release of carbon dioxide, though the entry of 1 million cubic meters of lava during the January 2002 eruption had no effect. The carbon dioxide would then suffocate large numbers of people in the lake basin as the gases roll off

1650-516: The lake. White Nile The White Nile ( Arabic : النيل الأبيض an-nīl al-'abyaḍ ) is a river in Africa, the minor of the two main tributaries of the Nile , the larger being the Blue Nile . The name "White" comes from the clay sediment carried in the water that changes the water to a pale color. In the strict meaning, "White Nile" refers to the river formed at Lake No , at

1700-587: The lake. The introduced species are three cichlids, the longfin tilapia ( Oreochromis macrochir ), blue-spotted tilapia ( O. leucostictus ) and redbreast tilapia ( Coptodon rendalli ), and a clupeid, the Lake Tanganyika sardine ( Limnothrissa miodon ) The sardine is referred to locally as ' Ndagala ' or 'Isambaza'. The exploitable stock of the Lake Tanganyika sardine was estimated at 2,000–4,000 metric tons (2,000–3,900 long tons) per year. It

1750-513: The lakeside human population but from an ecosystem standpoint, the introduction of planktivorous fish may result in important modifications of plankton community structure. Recent observations showed the disappearance during the last decades of a large grazer, Daphnia curvirostris , and the dominance of mesozooplankton community by three species of cyclopoid copepod: Thermocyclops consimilis , Mesocyclops aequatorialis and Tropocyclops confinis . The first comprehensive phytoplankton survey

1800-402: The largest reserves of eastern lowland (or Grauer's) gorillas in the world), combined with the elevation of the eastern rift (located in eastern Rwanda) would be responsible for the drainage of water from central Rwanda in the actual Lake Kivu. This concept of "proto-lake Kivu" was challenged by lack of consistent geological evidence, although the cichlid's molecular clock suggests the existence of

1850-550: The local grid, has since been completed. The next phase aims to deploy nine additional gensets at 75 MW to create a total capacity of 101 MW. In addition, Symbion Power Lake Kivu Limited was awarded a Concession and Power Producing Agreement (PPA) in 2015, to produce 50 MW of power using Lake Kivu methane. The project is expected to commence construction in 2019, with first power (Phase 1 - 14 MW) to be produced in first quarter 2020. The plant will be fully operational in 2021. Symbion Power has purchased another concession for

1900-534: The mouth of the Sobat are very gently sloping and hold many swamps and lagoons. When in flood, the Sobat River tributary carries a large amount of sediment , adding greatly to the White Nile's pale color. From South Sudan's second city Malakal , the river runs slowly but swamp-free into Sudan and north to Khartoum. Downstream from Malakal lies Kodok , the site of the 1898 Fashoda Incident that marked an end to

1950-559: The process of releasing it could potentially have costs beyond simply building and operating the system. This problem associated with the prevalence of methane is that of mazuku , the Swahili term "evil wind" for the outgassing of methane and carbon dioxide that kills people and animals, and can even kill vegetation when in high enough concentration. Lake Kivu has recently been found to contain approximately 55 billion m (1.9 trillion cu ft) of dissolved biogas at

2000-421: The rare mineral monohydrocalcite interlaid with diatoms , on top of sapropelic sediments with high pyrite content. These are found at three different intervals. The sapropelic layers are believed to be related to hydrothermal discharge and the diatoms to a bloom which reduced the carbon dioxide levels low enough to precipitate monohydrocalcite. Scientists hypothesise that sufficient volcanic interaction with

2050-442: The risk the lake posed to the local population. An experimental vent pipe was installed at Lake Nyos in 2001 to remove gas from the deep water, but such a solution for the much larger Lake Kivu would be considerably more expensive. The approximately 510 million metric tons (500 × 10 ^ long tons) of carbon dioxide in the lake is a little under 2 percent of the amount released annually by human fossil fuel burning. Therefore,

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2100-670: The river becomes known as the "Mountain Nile" or "Baḥr al-Jabal" (also "Baḥr el-Jebel", بحر الجبل ), literally Mountain River" or "River of the Mountain". The Southern Sudanese state of Central Equatoria through which the river flows was known as Bahr al-Jabal until 2006. The southern stretch of the river encounters several rapids before reaching the Sudan plain and the vast swamp of the Sudd . It makes its way to Lake No, where it merges with

2150-476: The river is otherwise done by small boat or canoe. From the point at which the river enters South Sudan from Uganda, the river goes under the name of "Mountain Nile". From Lake No in South Sudan the river becomes the "White Nile" in its strictest sense, and so continues northwards into Sudan where it ends at its confluence with the Blue Nile. From Nimule in South Sudan, close to the border with Uganda,

2200-456: The rivers are navigable up to Gambela, Ethiopia , and Wau, South Sudan . Monohydrocalcite Monohydrocalcite is a mineral that is a hydrous form of calcium carbonate , CaCO 3 ·H 2 O. It was formerly also known by the name hydrocalcite, which is now discredited by the IMA . It is a trigonal mineral which is white when pure. Monohydrocalcite is not a common rock-forming mineral, but

2250-467: The volcanic CO 2 . A future overturn and gas release from the deep waters of Lake Kivu would result in catastrophe, dwarfing the historically documented lake overturns at the much smaller Lakes Nyos and Monoun. The lives of the approximately two million people who live in the lake basin area would be threatened. Cores from the Bukavu Bay area of the lake reveal that the bottom has layered deposits of

2300-456: The water pressure gets lower. This project is expected to increase Rwanda's energy generation capability by as much as 20 times, and will enable Rwanda to sell electricity to neighbouring African countries. The firm was awarded the 2011 Africa Power deal of the year for innovation in the financing arrangements it obtained from various sources for the KivuWatt project. The $ 200 million power plant

2350-490: Was introduced to Lake Kivu in late 1959 by the Belgian agronomist Alphonse Collart. An attempt to introduce the similar Lake Tanganyika sprat ( Stolothrissa tanganicae ) at the same time was unsuccessful. At present, Lake Kivu is the sole natural lake in which L. miodon , a sardine originally restricted to Lake Tanganyika, has been introduced initially to fill an empty niche. Prior to the introduction, no planktivorous fish

2400-703: Was operating at 26 MW in 2016. The fish fauna in Lake Kivu is relatively poor with 28 described species, including four introduced species . The natives are the Lake Rukwa minnow ( Raiamas moorii ), four species of barb ( ripon barbel , Barbus altianalis , East African red-finned barb , Enteromius apleurogramma , redspot barb , E. kerstenii and Pellegrin's barb , E. pellegrini ), an Amphilius catfish, two Clarias catfish ( C. liocephalus and C. gariepinus ), Nile tilapia ( Oreochromis niloticus ) and 15 endemic Haplochromis cichlids. Another c. 20 possibly undescribed species of cichlids are known from

2450-437: Was present in the pelagic waters of Lake Kivu. In the early 1990s, the number of fishers on the lake was 6,563, of which 3,027 were associated with the pelagic fishery and 3,536 with the traditional fishery. The widespread armed conflict in the surrounding region from the mid-1990s resulted in a decline in the fisheries harvest. Following this introduction, the sardine has gained substantial economic and nutritional importance for

2500-495: Was released in 2006. With an annual average chlorophyll a in the mixed layer of 2.2 mg m and low nutrient levels in the euphotic zone, the lake is clearly oligotrophic . Diatoms are the dominant group in the lake, particularly during the dry season episodes of deep mixing. During the rainy season, the stratified water column, with high light and lower nutrient availability, favour dominance of cyanobacteria with high numbers of phototrophic picoplankton. The actual primary production

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