Jan Mayen (yän mĪˈən) [key], island, c.145 sq mi (380 sq km), in the Arctic Ocean, c.300 mi (480 km) E of Scoresby Sound, E Greenland. It was annexed by Norway in 1929. The island is barren tundra land rising abruptly to Håkon VII Toppen (c.7,450 ft/2,270 m) on Mt. Beerenberg, an extinct volcano. Fog and stormy weather characterize the island. Except for a radio-meteorological station, the island is uninhabited, but it is visited by sealers. It was discovered (1607) by Henry Hudson and named for Jan Jacobsz May, a Dutch whaler who landed there in 1614.