Amundsen Basin Basin formed during the Cenozoic Era from seafloor spreading. Amundsen Basin The Amundsen Basin, with depths up to 4.4 km, is the deepest abyssal plain in the Arctic Ocean. The Amundsen Basin is embraced by the Lomonosov Ridge (from to ) and the Gakkel Ridge (from to ). It is named after the polar researcher Roald Amundsen. Together with the Nansen Basin, the Amundsen Basin is often summarized as Eurasian Basin. The Russian-American cooperation Nansen and Amundsen Basin Observational System (NABOS) aims "to provide a quantitative observationally based assessment of circulation, water mass transformations, and transformation mechanisms in the Eurasian
Nansen (lunar crater) lies across the northern rim of Nansen, and a similar formation is located along the inner southern wall. A merged chain of tiny craters lies across the eastern rim. The interior floor of Nansen is more hummocky and irregular in the northern half, while the southern part of the floor is relatively level. There is a small, bowl-shaped crater in the southeastern part of the floor, and many tiny craterlets lie across the interior and along the inner walls. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that