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 and after two false starts, Nansen and Johansen began their journey on 14 March 1895. Nansen allowed 50 days to cover the to the pole, an average daily journey of . After a week of travel, a sextant observation indicated they averaged per day, which put them ahead of schedule. However, uneven surfaces made skiing more difficult, and their speeds slowed. They also realised they were marching against a southerly drift, and that distances travelled did not necessarily equate to distance progressed. On 3 April, Nansen began to doubt whether the pole was attainable. Unless their speed improved, their food