Helicopters provide close support for many research teams. McMurdo, on a barren area of Ross Island, is the largest station in Antarctica. It has more than 80 buildings, including laboratories for biology, earth science, meteorology, and upper atmosphere science. McMurdo is the logistics hub for much of the program. In December, when summer heat has softened the sea ice, air operations shift to a skiway on the Ross Ice Shelf, which only ski-equipped airplanes can use.
Wheeled airplanes can use yet another runway on glacier ice during all but the warmest months.
McMurdo is the world's farthest south land that can be reached by ship. In January a Coast Guard icebreaker breaks out the sea ice that weeks earlier was a runway, and a tanker and a cargo ship deliver a year's supply of fuel, materials, and food. The summer population of scientists and support personnel at McMurdo sometimes exceeds 1,100. In February, the last plane of the season leaves a wintering population of about 250. Amundsen-Scott Station, at the geographic south pole, is built on the antarctic ice sheet.