Lake Natron, Tanzania

Detail of white-boxed area (43 Kb)
High-resolution mosaic image (772 Kb)

More images of Lake Natron

From STS-41B in 1984

From STS-29 in 1989

From STS-93 in 1999

If Lake Natron in Africa's Great Rift Valley had a color theme, it would be pink. The alkali salt crust on the surface of the lake is often colored red or pink by the salt-loving microorganisms that live there. The lake is the only breeding area for the 2.5 million lesser flamingoes that live in the valley. These flamingoes flock along saline lakes in the region, where they feed on Spirulina platensis, a blue-green alga with red pigments. Lake Natron is the only breeding location for lesser flamingoes because its caustic environment is a barrier against predators trying to reach their nests. The temperatures in the mud can reach 50 degrees Celsius (122 degrees Fahrenheit), and depending on recent rainfall, the alkalinity can reach a pH between 9 and 10.5, which is almost as alkaline as straight ammonia. Even more amazing than the ability of the flamingoes to live in these conditions is the fact that an endemic species of fish -- the alkaline tilapia -- thrives in the waters at the edges of the hot spring inlets. The unique biodiversity of Lake Natron Basin led Tanzania to name it to the Ramsar List of Wetlands of International Importance on July 4, 2001.

This mosaic of photographs of the southern portion of Lake Natron shows the largest open lagoon area, an island mud flat and a large area of pink salt crust. The images were taken by astronauts from the International Space Station on Nov. 11, 2002, using a digital camera with a 400-mm lens and 2X extender in order to capture the details of the salt crust structures. The image shows the actual colors viewed by the astronauts. Each time the lake is photographed, there are differences in the pattern of its salt crust and the red colors of the blue-green algae and bacteria on the surface of the crust.

Astronaut photographs ISS005-E-20454 and ISS005-E-20455 and the mosaic were provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.