On May 18, 2014 the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite flew over the northern Caspian Sea and captured this true-color image of the region. A broad band of brown dust rises from the west of the Volga River and blows over the Kalmykia and Asktrakhan region of Russia. A longer plume, like arising from Turkmenistan, blows southeast across the blue waters of the Caspian Sea.
Covering an area of roughly 371,000 square km (143,200 sq. mi.), the Caspian Sea is the world’s largest salt lake. The water appears green in its shallow northern part, where it has an average depth of just 5-6 meters (16-20 feet). The southern part of the Caspian Sea is much deeper and appears dark blue.