Bouvet Island of establishing a manned meteorological radio station, but a suitable location could not be found. By then both the flagpole and hut from the previous year had been washed away. The Third "Norvegia" Expedition, led by Hjalmar Riiser-Larsen, arrived the following year and built a new hut at Kapp Circoncision and on Larsøya. The expedition carried out aerial photography of the island and was the first Antarctic expedition to use aircraft. The "Dependency Act", passed by the Parliament of Norway on 27 February 1930, established Bouvet Island as a dependency, along with Peter I Island and Queen Maud Land. The
Atlantic Ocean has a volume of . The North Atlantic covers (11.5%) and the South Atlantic (11.1%). The average depth is and the maximum depth, the Milwaukee Deep in the Puerto Rico Trench, is . The bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge (MAR). It runs from 87°N or south of the North Pole to the subantarctic Bouvet Island at 42°S. The MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above along most of its length, but