The Discovery of Salty Lakes on Earth from Space

The Copernicus Sentinel-2 mission recently captured stunning images of two beautiful and colorful lakes in East Africa: Lake Natron in northern Tanzania and Lake Magadi in southern Kenya. These images provide a unique glimpse into the natural wonders of these salty lakes and the diverse ecosystems they support.

Lake Natron, located at the bottom of the image, stretches an impressive 56 kilometers in length. Despite its shallow depth of only 3 meters, which varies throughout the year, Lake Natron is considered a Ramsar wetland of international importance. This designation is due to its role as the sole breeding area for lesser flamingos in East Africa. As many as 2.5 million flamingos can be found congregating on the lake, making it a truly spectacular sight. Additionally, Lake Natron provides a habitat for thousands of other species of waterbirds.

Moving to the center top of the image, we find Lake Magadi. This smaller lake is situated in a vast depression surrounded by volcanic rock. Unlike Lake Natron, Lake Magadi does not receive water from permanent rivers. Instead, it relies solely on surface runoff during rainfall. Similar to Lake Natron, Lake Magadi has a high salt content, with salt deposits reaching up to 40 meters in some areas. Interestingly, this lake is one of the few places on Earth where the mineral trona occurs naturally. Trona has various industrial uses, including glass manufacturing, fabric dyeing, and paper production.

The image was captured on February 12, 2023, just before the main rainy season that begins in March. During this time, both lakes exhibit vibrant red or pink colors due to the presence of algae thriving on the salt. As water evaporates and salts become more concentrated during the dry season, these colors become even more pronounced. The use of Sentinel-2’s near-infrared channel in image processing helps reveal unique information not visible in natural color images. In this false-color image, vegetated areas appear as shades of red, while the seasonal flowering of algae in the lakes appears green. The bright white and blue areas along the shores represent a combination of sand, salt, and mud flats. The white dots speckling the waters are salt crusts formed through evaporation caused by high temperatures.

The Copernicus Sentinel-2 mission is a two-satellite initiative that plays an important role in supplying coverage and data for Europe’s Copernicus program. Its frequent revisits over the same area and high spatial resolution enable scientists to monitor changes in the conditions of inland water bodies, including lakes. This capability is one of the mission’s primary applications, alongside land cover, agriculture, and forestry analysis.

To wrap it up, the Copernicus Sentinel-2 mission has provided us with breathtaking images of Lake Natron and Lake Magadi in East Africa. These lakes, with their unique characteristics and vibrant colors, serve as important habitats for various species, including lesser flamingos. The images not only showcase the natural beauty of these lakes but also highlight the invaluable role played by the Sentinel-2 mission in monitoring and understanding our planet’s water bodies.