Lake, mainly in northern Kenya. The fourth largest of the eastern African lakes, it lies 1,230 ft (375 m) above sea level in the Great Rift Valley and covers an area of 2,473 sq mi (6,405 sq km). The three main islands in the lake are volcanic. The lake is relatively shallow; its greatest recorded depth is 240 ft (73 m). Having no outlet, the lake's waters are brackish. Sudden storms are frequent, rendering navigation treacherous. It is a rich reservoir of fish.
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The rocks of the surrounding area are predominantly volcanic. Central Island is an active volcano, emitting vapors. Outcrops and rocky shores are found on the East and South shores of the lake, while dunes, spits and flats are on the West and North, at a lower elevation.
On-shore and off-shore winds can be extremely strong as the lake warms and cools more slowly than the land. Sudden, violent storms are frequent. Three rivers (the Omo, Turkwel and Kerio) flow into the lake, but lacking outflow its only water loss is by evaporation. Lake volume and dimensions are variable. For example, its level fell by 10 meters between 1975 and 1993.
Due to temperature, aridity and geographic inaccessibility, the lake retains its wild character. Nile crocodiles are found in great abundance on the flats. The rocky shores are home to scorpions and carpet vipers. Although the lake and its environs have been popular for expeditions of every sort under the tutelage of guides, rangers and experienced persons, they certainly must be considered hazardous for unguided tourists.
Lake Turkana National Parks are now listed as a UNESCO World Heritage Site. Sibiloi National Park lies on the lake's eastern shore, while Central Island National Park and South Island National Park lie in the lake. Both are known for their crocodiles.
The lake was named Lake Rudolf (in honor of Crown Prince Rudolf of Austria) by Count Sámuel Teleki de Szék and his second-in-command Lieutenant Ludwig Ritter Von Höhnel, a Hungarian and an Austrian , in 1888. They were its first European discoverers, "finding" it on a large safari across East Africa on March 6, 1888. It was never really lost, of course, having long been known to the native tribes of the region. They include the Turkana, Rendille, Gabbra, Daasanach, Hamar Koke, Karo, Nyagatom, Mursi, Surma and Molo. For the location of many of these peoples refer to the dialect map in the article.
J. W. Gregory reported in The Geographical Journal of 1894 that it had been called 'Basso Narok'This means black lake in the samburu language and basso naibor for lake Stefanie meaning white lake in the samburu language. The samburu are among the dominant tribes in the lake Turkana region when the explorers came. . What the native form of this phrase was, what it might mean and in what language is not clear. The lake kept its European name during the colonial period of British East Africa. After the independence of Kenya, the president, Mzee Jomo Kenyatta, renamed it in 1975 after the Turkana, the predominant tribe there.
At some unknown time the lake became known as the Jade Sea from its turquoise color seen on approaching from a distance. The color comes from algae that rise to the surface in calm weather. This is likely also a European name. The Turkana refer to the lake as anam Ka'alakol, meaning the sea of many fish. It is from the name Ka'alakol that Kalokol, a town on the western shore of Lake Turkana, east of Lodwar, derives its name. The area still sees few Western visitors, being a three-day drive from Nairobi, 400 km to the south.
Some birds more common to Turkana are the Little Stint, the Wood Sandpiper, and the Common Sandpiper. The African Skimmer (Rhyncops flavirostris) nests in the banks of Central Island. The White-necked Cormorant (Phalacrocorax africanus) ranges over the lake. The Greater Flamingo wades in its shallows. Heuglin's Bustard (Neotis heuglinii) is found in the east of the lake region.
The basement rocks of the region have been dated by two analytical determinations to 522 and 510 million years ago (ma or mya). No rift was in the offing at that time. A rift is signalled by volcanic activity through the weakened crust. The oldest volcanic activity of the region occurred in the Nabwal Hills northeast of Turkana and is dated to 34.8 mya in the late Eocene.
The visible tectonic features of the region result from extensive extrusions of basalt over the Turkana-Omo basin in the window 4.18-3.99 mya. These are called the Gombe Group Basalts. They are subdivided into the Mursi Basalts and the Gombi Basalts.
The two latter basalts are identified as the outcrops that are the rocky mountains and badlands around the lake. In the Omo portion of the basin, of the Mursi Basalts, the Mursi Formation is on the west side of the Omo, the Nkalabong on the Omo, and the Usno and Shungura east of the Omo. Probably the best known of the formations are the Koobi Fora on the east side of Turkana and the Nachukui on the west.
Short-term fluctuations in lake level combined with periodic volcanic ash spewings over the region have resulted in a fortuitous layering of the ground cover over the basal rocks. These horizons can be dated more precisely by chemical analysis of the tuff. As this region is believed to have been an evolutionary nest of Hominins, the dates are important for generating a diachronic array of fossils, both Hominoid and non-Hominoid. Many thousands have been excavated.
Terraces representing ancient shores are visible in the Turkana basin. The highest is 75 m above the surface of the lake (only approximate, as the lake level fluctuates), which was current about 9500 years ago, at the end of the Pleistocene. It is generally theorized that Turkana was part of the upper Nile system at that time, connecting to Lake Baringo at the southern end and the White Nile in the north, and that volcanic land adjustments severed the connection. Such a hypothesis explains the Nile species in the lake, such as the crocodiles and the Nile Perch.