Barents Sea (Russian Barentsovo More), arm of the Arctic Ocean, named for its discoverer, the Dutch navigator Willem Barents. The sea is bounded on the west by the Norwegian archipelago of Svalbard and on the east by the two islands of Novaya Zemlya, which belong to Russia. The sea extends north from Norway, Finland, and Russia for 1,500 km (900 mi), and is bounded on the north by Franz Josef Land (Zemlya Frantsa Iosifa). The sea is shallow, and the southern part is free of ice all year. During World War II (1939-1945) the Barents Sea served as an important traffic route; it provided the only direct surface approach to the Union of Soviet Socialist Republics (USSR). At present it forms the westernmost part of the 8,000-km (5,000-mi) seaway leading from Murmansk in Europe to Vladivostok on the Pacific Ocean.