Rollin A. Harris used a few scattered tide observations on the periphery of the Arctic Ocean to contradict Nansen's statement that the Arctic Sea was an open basin of deep water occupying all, or nearly all, of the large unexplored area (in 1911) of the Arctic. Harris concluded that there was either a land mass or some shallow water near the north pole. Fjeldstad disagreed with Harris in 1923, and in 1927, Sverdrup supported Fjeldstad, using additional tide and current observations to reach this conclusion. Later, about 1950, Soviet scientists discovered the Lomonosov and Mendeleyev ridges, and shortly thereafter, U.S. scientists found the Alpha Ridge, all three ridges lying at least partially in what was in 1911 unexplored territory. It appears that Harris' hypothesis was at least partially accurate.