extensive valley glacier, situated in the Central Asian Pamirs range, central Tajikistan. The world's largest glacier found outside the polar regions, it is about 45 miles (70 km) long and covers up to some 350 square miles (900 square km). It flows north from the ice field of Revolution Peak (22,880 feet 【6,974 metres】), receiving ice from dozens of tributary glaciers. The glacier in its middle course can move up to 26 inches (67 cm) per day. Its meltwater forms the headstream of the Surkhob River and the Amu Darya.

The glacier was discovered in 1878 and named for the 19th-century Russian explorer A.P. Fedchenko. Its middle and upper reaches were first explored in 1928 as part of a major Soviet expedition to the Pamirs region. Over the years the glacier has been the site of several meteorological stations.