Arctic Ocean deepest point is Litke Deep in the Eurasian Basin, at . The two major basins are further subdivided by ridges into the Canada Basin (between Alaska/Canada and the Alpha Ridge), Makarov Basin (between the Alpha and Lomonosov Ridges), Amundsen Basin (between Lomonosov and Gakkel ridges), and Nansen Basin (between the Gakkel Ridge and the continental shelf that includes the Franz Josef Land). In large parts of the Arctic Ocean, the top layer (about ) is of lower salinity and lower temperature than the rest. It remains relatively stable, because the salinity effect on density is bigger than the temperature effect.
Fridtjof Nansen like a spiral staircase, down towards the depths". In 1909 Nansen combined with Bjørn Helland-Hansen to publish an academic paper, "The Norwegian Sea: its Physical Oceanography", based on the "Michael Sars" voyage of 1900. Nansen had by now retired from polar exploration, the decisive step being his release of "Fram" to fellow Norwegian Roald Amundsen, who was planning a North Pole expedition. When Amundsen made his controversial change of plan and set out for the South Pole, Nansen stood by him. Between 1910 and 1914, Nansen participated in several oceanographic voyages. In 1910, aboard the Norwegian naval vessel "Fridtjof", he