Editing Lake Tanganyika (section)

==Geography==
Lake Tanganyika is situated within the [[Albertine Rift]], the western branch of the [[East African Rift]], and is confined by the mountainous walls of the valley. It is the largest [[rift lake]] in Africa and the second-largest freshwater lake by volume in the world. It is the deepest lake in Africa and holds the greatest volume of fresh water on the continent, accounting for 16% of the world's available fresh water. It extends for {{cvt|676|km|mi}} in a general north–south direction and averages {{cvt|50|km|mi}} in width. The lake covers {{cvt|32000|km2|sqmi}}, with a shoreline of {{cvt|1900|km|mi}}, a mean depth of {{cvt|572|m|ft}} and a maximum depth of {{cvt|1471|m|ft}} (in the northern basin). It holds an estimated {{cvt|18750|km3|cumi}} of water.<ref>{{cite web |url=http://www.ilec.or.jp/database/afr/dafr06.html |title=Datbase Summary: Lake Tanganyika |website=ilec.or.jp |access-date=2008-03-14 |url-status=dead |archive-url=https://web.archive.org/web/19991110092358/http://www.ilec.or.jp/database/afr/dafr06.html |archive-date=1999-11-10 |publisher=International Lake Environment Committee Foundation |place=Japan}}</ref><ref name=asdf />

The [[Drainage basin|catchment area]] of the lake is {{cvt|231000|km2|mi2}}. Two main rivers flow into the lake, as well as numerous smaller rivers and streams (whose lengths are limited by the steep mountains around the lake). The one major outflow is the [[Lukuga River]], which empties into the [[Congo River]] drainage. Precipitation and evaporation play a greater role than the rivers. At least 90% of the water influx is from rain falling on the lake's surface and at least 90% of the water loss is from direct evaporation.<ref name= Kullander2011>{{cite journal |last1=Kullander |first1=S.O. |author1-link=Sven O. Kullander |first2=T.R. |last2=Roberts |year=2011 |title=Out of Lake Tanganyika: endemic lake fishes inhabit rapids of the Lukuga River |journal=Ichthyol. Explor. Freshwaters |volume=22 |issue=4 |pages=355–76}}</ref>

The major river flowing into the lake is the [[Ruzizi River]], formed about 10,000 years ago, which enters the north of the lake from [[Lake Kivu]].<ref name="readersnatural">{{Cite book |title=Natural Wonders of the World |publisher=Reader's Digest Association, Inc |year=1980 |isbn=978-0-89577-087-5 |editor-last=Scheffel |editor-first=Richard L. |location=US |pages=366–67 |editor-last2=Wernet |editor-first2=Susan J.}}</ref> The [[Malagarasi River]], which is Tanzania's second largest river, enters the east side of Lake Tanganyika.<ref name="readersnatural" /> The Malagarasi is older than Lake Tanganyika, and before the lake was formed, it probably was a headwater of the [[Lualaba River]], the main Congo River headstream.<ref name=Kullander2011/>

The lake has a complex history of changing flow patterns, due to its high altitude, great depth, slow rate of refill, and mountainous location in a turbulently volcanic area that has undergone climate changes. Apparently, it has rarely in the past had an outflow to the sea. It has been described as "practically [[endorheic]]" for this reason. The lake's connection to the sea is dependent on a high water level allowing water to overflow out of the lake through the Lukuga River into the Congo.<ref name="readersnatural" /> When not overflowing, the lake's exit into the Lukuga River typically is blocked by sand bars and masses of weed, and instead this river depends on its own tributaries, especially the Niemba River, to maintain a flow.<ref name=Kullander2011/>

The lake may also have at times had different inflows and outflows; inward flows from a higher [[Lake Rukwa]], access to [[Lake Malawi]] and an exit route to the [[Nile]] have all been proposed to have existed at some point in the lake's history.<ref>{{cite book |last=Lévêque |first=Christian |title=Biodiversity Dynamics and Conservation: The Freshwater Fish of Tropical Africa |isbn=978-0521570336 |year=1997 |publisher=[[Cambridge University Press]] |page=110}}</ref>

Lake Tanganyika is an [[ancient lake]], one of only twenty more than a million years old. Its three basins, which in periods with much lower water levels were separate lakes, are of different ages. The central began to form 9–12 million years ago (Mya), the northern 7–8 Mya and the southern 2–4 Mya.<ref>{{cite journal |last1=Cohen |last2=Soreghan |last3=Scholz |year=1993 |title=Estimating the age of formation of lakes: An example from Lake Tanganyika, East African Rift system |journal=Geosciences |volume=21 |issue=6 |pages=511–514 |doi=10.1130/0091-7613(1993)021<0511:ETAOFO>2.3.CO;2 |bibcode=1993Geo....21..511C}}</ref>