Ellef Ringnes Island is an uninhabited island and one of the Sverdrup Islands in the Qikiqtaaluk Region, Nunavut, Canada. A member of the Queen Elizabeth Islands and Arctic Archipelago, it is located in the Arctic Ocean, east of Borden Island, and west of Amund Ringnes Island. It has an area of , making it the 69th largest island in the world (slightly larger than Jamaica) and Canada's 16th largest island. Its highest mount is . The island was named by Otto Sverdrup for Oslo brewer Ellef Ringnes, one of the sponsors of his expedition. It was first sighted by Europeans in 1901 by one of Sverdrup's men. The island was then claimed by Norway from 1902 until the claim was relinquished in favour of Canada in 1930. History The first known European sighting of Ellef Ringnes Island was in 1901 by a sledging party consisting of Gunerius Isachsen and Sverre Hassel, members of the Second Norwegian Arctic Expedition of 1898–1902, which was under the command of Otto Sverdrup. The island was named to honour Ellef Ringnes, one of the principal patrons of the expedition. At the time of the discovery of Ellef Ringnes Island, the expedition was based at Goose Fiord on the south coast of Ellesmere Island. Isachsen and Hassel made their initial sighting of Ellef Ringnes Island on April 23 that year, as they rounded the southwest corner of Amund Ringnes Island, an island they had sighted and partly explored the previous year. The following day, Isachsen and Hassel travelled across Hassel Sound making a landfall at the southern extremity of the island. In the course of the following 20 days, they succeeded in circumnavigating Ellef Ringnes. The resulting map and notes on geological specimens are published in Otto Sverdrup's narrative New Land (1904). In 1948. the Canadian Department of Transport and the United States Weather Bureau jointly established a meteorological station at Isachsen. The station was in operation for thirty years. Drilling took place on the island in the seventies by Panarctic Oils. A High Arctic Weather Station (HAWS) called Isachsen lies on the west coast of the island. It was opened April 3, 1948 as part of a joint Canada-United States military effort to support a weather station network. When it closed on September 19, 1978, it was replaced with an automatic weather station. The station represented the only known permanent human settlement of the island.