Image:Lake Natron from space STS-55.jpg

           STS-55 Earth observation taken aboard Columbia, 
           Orbiter Vehicle (OV) 102, shows Lake Natron in Tansania, in the 35-mile-wide 
           East African Rift Valley. This lake is surrounded by sodium carbonate
           volcanoes. Through erosion, these salts of volcanic origin are 
           transported into the rift valley lakes. The various shades of bright red reflecting 
           from the lake result from the water chemistry and biotic blooms. The white spots in the 
           lakebed are drying soda salts. The depth and circulation of the water in the southern 
           end of the lake cause it to appear dark blue rather than bright red. In the repeated 
           photographs of this lake from orbit, we have seen the extent and intensity of its colors 
           fluctuate seasonally. In this photograph, the biotic activity appears to be at a peak. Such 
           a large extent of red-colored water was not present in the photos taken from STS-56, just a 
           few days before (April 10, 1993). 

           Terms:
           AFRICA COLUMBIA (ORBITER)
          EARTH OBSERVATIONS (FROM SPACE) 
          INFRARED PHOTOGRAPHY LAKES
          STS-55 TANZANIA