Lake Natron

Lake World Wonders, World

Lake Natron is a saline lake in northern Tanzania located in the African Rift Valley at about 600 meters above sea level, near the Kenyan border. Near its southeast bank is the Gelai Volcano. The lake, which barely reaches three meters in depth, varies in size according to the level of filling of its reservoir. Its characteristic color, a dark and deep red with superficial whitish streaks due to the accumulation of sodium, is a particularity common to that type of lakes in which intense cycles of evaporation occur.

The lake is fed principally by the Southern Ewaso Ng'iro River, which rises in central Kenya, and by mineral-rich hot springs. It is quite shallow, less than three metres (9.8 ft) deep, and varies in width depending on its water level. The lake is a maximum of 57 kilometres (35 mi) long and 22 kilometres (14 mi) wide. The surrounding area receives irregular seasonal rainfall, mainly between December and May totalling 800 millimetres (31 in) per year. Temperatures at the lake are frequently above 40 °C (104 °F).High levels of evaporation have left behind natron (sodium carbonate decahydrate) and trona (sodium sesquicarbonate dihydrate). The alkalinity of the lake can reach a pH of greater than 12. The surrounding bedrock is composed of alkaline, sodium-dominated trachyte lavas that were laid down during the Pleistocene period. The lavas have significant amounts of carbonate but very low calcium and magnesium levels. This has allowed the lake to concentrate into a caustic alkaline brine.