An astronaut aboard the International Space Station (ISS) took this photograph of a chain of small lakes in the treeless prairie, or steppe, from Western Kazakhstan. The colored lakes lie a few meters below sea level. This part of Kazakhstan is a plain that slopes down to the Caspian Sea, 300 kilometers to the south, itself located about 27 meters (90 feet) below sea level. of the sea.
Small settlements (such as Kumankol) dot these semi-arid landscapes, but they can be difficult to discern in images from satellites and space stations. Hundreds of these pastoral establishments are spread across the countryside of Kazakhstan. A main road crosses the bottom of the photo.
The Ashiozek River, marked by many meanders, brings water south to the lakes. The river extends in a small delta, and water flows through these branches to Aralsor and Zhalnak lakes and other depressions further south. (For scale, Lake Aralsor is 15 kilometers or 9.5 miles wide in an east-west direction.) The margin of a vegetated dune field is visible in the lower left corner; dunes often accompany such lakes in this region.
Evaporation increases the salinity of the water in this region, allowing different species of salt-loving microorganisms to thrive. The different salinity and temperature in each lake influences the dominant microbe species that thrive. Different microorganisms display varying colors as the varying depth of the lake water accentuates or softens the tones. Exposed salt – not an active microbial community – may account for the bright white of the smaller lake bed in the lower right.
The phenomenon of colored neighboring lakes occurs in all semi-arid subtropical zones, as demonstrated by astronaut images of Lake Eyre in Australia and Etosha Casserole in Namibia. Evaporation ponds on the margin of the Great Salt Lake (pans designed for salt production) show the same kind of variable color differences. In most cases, the colors red and orange indicate higher salt concentrations and microbial activity than blue water.
Astronaut Photography ISS067-E-133135 was acquired on June 15, 2022, with a Nikon D5 digital camera using a 400 millimeter focal length. It is provided by the ISS Crew Earth Observation Facility and the Earth Science and Remote Sensing Unit at Johnson Space Center. The image was taken by a member of the Expedition 67 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory in the context of ISS National Laboratory to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make these images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Justin Wilkinson, Texas State University, JETS contract at NASA-JSC.