While orbiting over the northern Tibetan Plateau, an astronaut aboard the International Space Station captured this photograph of Siling Lake. The lake, also called Selincuo, is one of the largest water bodies on the Tibetan Plateau. In this image, fresh snowfall from the previous day blankets the landscape.
Located at an elevation of approximately 4,500 meters (14,860 feet), Siling Lake is a high-altitude endorheic lake, which means that it does not drain through any outlets. The lake is fed by precipitation—approximately 38 centimeters (15 inches) per year—as well as runoff from rain, snow, and glacial meltwater from the surrounding landscape. Siling Lake is a saline water body due to the lack of outflow, which concentrates salts as the lake water evaporates.
The climate of Siling Lake is typically below freezing from December until mid-April, causing the lake to freeze over. The lake was not yet frozen on the day of this photograph, further amplifying the contrast between the white snow and the blue hues of the water.
Changes in global climate have led to fluctuations in lake size, with waterbodies on the southern Tibetan Plateau that have been shrinking, and lakes on the northern portion that have been growing. Siling Lake has been growing since the 1970s, and scientists have used several modeling approaches to try and explain this trend. However, conclusions have varied between two potential causes: an increase in glacial melt runoff, or a decrease in annual wind speed between the 1980s and early 2000s.
The Tibet Selincuo Wetlands around Siling Lake were designated as a Ramsar wetlands area in 2018. The wetlands provide important habitat for two vulnerable species of eagles, the Pallas’s fish-eagle (Haliaeetus leucoryphus) and the eastern imperial eagle (Aquila heliacal). Gymnocypris selincuoensis fish are also part of the wetlands ecology and are endemic to Siling Lake.
Astronaut photograph ISS066-E-86268 was acquired on December 4, 2021, with a Nikon D5 digital camera using a focal length of 400 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 66 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 as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Cadan Cummings, Jacobs, JETS Contract at NASA-JSC.