Arctic Ocean gas reserves, and the Chukchi shelf forms the border between Russian and the United States as stated in the USSR–USA Maritime Boundary Agreement. The whole area is subject to international territorial claims. An underwater ridge, the Lomonosov Ridge, divides the deep sea North Polar Basin into two oceanic basins: the Eurasian Basin, which is between deep, and the Amerasian Basin (sometimes called the North American, or Hyperborean Basin), which is about deep. The bathymetry of the ocean bottom is marked by fault block ridges, abyssal plains, ocean deeps, and basins. The average depth of the Arctic Ocean is . The
Fridtjof Nansen in January 1913 he received news of the suicide of Hjalmar Johansen, who had returned in disgrace from Amundsen's successful South Pole expedition. In March 1913, Nansen's youngest son Asmund died after a long illness. In the summer of 1913, Nansen travelled to the Kara Sea, by the invitation of Jonas Lied, as part of a delegation investigating a possible trade route between Western Europe and the Siberian interior. The party then took a steamer up the Yenisei River to Krasnoyarsk, and travelled on the Trans-Siberian Railway to Vladivostok before turning for home. Nansen published a report from the trip