The Volga Delta is the largest river delta in Europe and occurs where Europe's largest river system, the Volga River, drains into the Caspian Sea in Russia's Astrakhan Oblast, north-east of the republ
Volga Delta and northwestern Caspian Sea. While most of the green seen in this image appears to be diluted mud, some may be phytoplankton or algal blooms, particularly in the lower right corner of the image.