Amundsen Basin 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 and Canadian Basins of the Arctic Ocean". The Amundsen
Sistan Basin Mount Khajeh, rises beside the lakes and marshes of the basin. The lowest part of the Sistan Basin contains a series of shallow lakes, known as "hamuns". It appears that in the past there was a single Hamun Lake, but there are now three separate lakes. From north to south the lakes are: The Hamun-e Puzak lies mostly in Afghanistan. It receives water from the Shelah Charkh channel of the Helmand River, and also from the Khash River and other small rivers. The Hamun-e Sabari is split between Iran and Afghanistan. It receives water from the Parian branch of Helmand