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
Oriental Basin the lowest part of the basin (2300 meters elevation), and remain dry for most of the year. The basin includes six maar lakes, locally called "axalpazcos", lying in shallow volcanic craters and sustained by underground water. A northern group of lakes – Alchichica, Quechulac, Atexcac, and La Preciosa – lie southeast of Lake Tepeyahualco, and the southern lakes, Aljojuca and San Miguel Tecuitlapa, lie southeast of Lake Totolcinco. The basin also has five dry maars, called "xalapazcos". Chief towns in the basin include El Carmen Tequexquitla, Tlaxcala; Perote, Veracruz; and Oriental, Puebla. Groundwater levels in the basin have been dropping