On October 9, 2020, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired a true-color image of dust blowing over the Russian republics of Kalmykia and Dagestan. The streamers of light-colored dust appear to arise from point-sources near the coast of the Caspian Sea and possibly from arid, sandy areas on the interior. Strong winds began moving the dust to the northwest on October 9 and continued on October 10. Satellite imagery shows some dust still moving on October 11, but it is much diminished.
Covering an area of roughly 371,000 square kilometers (143,200 square miles), the Caspian Sea is the world’s largest salt lake. The water appears green in its shallow northern part, primarily from suspended sediment swirling in the shallow waters, where it has an average depth of just 5 to 6 meters (16 to 20 feet). The Caspian Sea is much deeper in the south and appears dark blue.