Lake Tanganyika

Lake Tanganyika
Lake Tanganyika from space, June 1985
map
Coordinates	6°30′S 29°50′E / 6.500°S 29.833°E / -6.500; 29.833Coordinates: 6°30′S 29°50′E / 6.500°S 29.833°E / -6.500; 29.833
Lake type	Rift Valley Lake
Primary inflows	Ruzizi River Malagarasi River Kalambo River
Primary outflows	Lukuga River
Catchment area	231,000 km2 (89,000 sq mi)
Basin countries	Burundi DR Congo Tanzania Zambia
Max. length	673 km (418 mi)
Max. width	72 km (45 mi)
Surface area	32,900 km2 (12,700 sq mi)
Average depth	570 m (1,870 ft)
Max. depth	1,470 m (4,820 ft)
Water volume	18,900 km3 (4,500 cu mi)
Residence time	5500 years
Shore length1	1,828 km (1,136 mi)
Surface elevation	773 m (2,536 ft)
Settlements	Kigoma, Tanzania Kalemie, DRC Bujumbura, Burundi
References
1 Shore length is not a well-defined measure.

Lake Tanganyika is an African Great Lake. It is estimated to be the second largest freshwater lake in the world by volume, and the second deepest, in both cases, after only Lake Baikal in Siberia; it is also the world's longest freshwater lake. The lake is divided among four countries – Tanzania, Democratic Republic of the Congo (DRC), Burundi, and Zambia, with Tanzania (46%) and DRC (40%) possessing the majority of the lake. The water flows into the Congo River system and ultimately into the Atlantic Ocean.

The name apparently refers to "Tanganika, 'the great lake spreading out like a plain', or 'plain-like lake'."

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 lake by volume in the world. It is the deepest lake in Africa and holds the greatest volume of fresh water, accounting for 18% of the world's available fresh water. It extends for 676 km (420 mi) in a general north-south direction and averages 50 km (31 mi) in width. The lake covers 32,900 km² (12,700 sq mi), with a shoreline of 1,828 km (1,136 mi), a mean depth of 570 m (1,870 ft) and a maximum depth of 1,470 m (4,820 ft) (in the northern basin). It holds an estimated 18,900 cubic kilometres (4,500 cu mi). This is equivalent to about 16% of all fresh water on Earth. It has an average surface temperature of 25 °C (77 °F) and a pH averaging 8.4.

The enormous depth and tropical location of the lake can prevent 'turnover' of water masses, which means that much of the lower depths of the lake are so-called 'fossil water' and are anoxic (lacking oxygen). The catchment area of the lake is 231,000 km² (89,000 sq mi). 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). There is one major outflow, the Lukuga River, which empties into the Congo River drainage.