The Amundsen Sea, an arm of the Southern Ocean off Marie Byrd Land in western Antarctica, lies between Cape Flying Fish (the northwestern tip of Thurston Island) to the east and Cape Dart on Siple Island to the west. Cape Flying Fish marks the boundary between the Amundsen Sea and the Bellingshausen Sea. West of Cape Dart there is no named marginal sea of the Southern Ocean between the Amundsen and Ross Seas. The Norwegian expedition of 1928–1929 under Captain Nils Larsen named the body of water for the Norwegian polar explorer Roald Amundsen while exploring this area in February 1929.
The sea is mostly ice-covered, and the Thwaites Ice Tongue protrudes into it. The ice sheet which drains into the Amundsen Sea averages about 3 km (1.9 mi) in thickness; roughly the size of the state of Texas, this area is known as the Amundsen Sea Embayment (ASE); it forms one of the three major ice-drainage basins of the West Antarctic Ice Sheet.
The ice sheet which drains into the Amundsen Sea averages about 3 km (1.9 mi) in thickness; is roughly the size of the state of Texas and the area is known as the Amundsen Sea Embayment (ASE); it forms one of the three major ice drainage basins of the West Antarctic Ice Sheet, the others being the Ross Sea Embayment and the Weddell Sea Embayment. In March 2007, scientists studying the ASE through satellite and airborne surveys announced a significant thinning of the ASE, due to shifts in wind patterns that allow warmer waters to flow beneath the ice sheet.