Jan Mayen Island, a Norwegian island in the Arctic Ocean. It is 660 miles (1,060 km) west of Tromso, Norway, and 280 miles (450 km) east of Greenland. The area is 147 square miles (380 km2). The highest point is the 7,470-foot (2,277-m) Beerenberg, an extinct volcano. Sealers and fox hunters visit Jan Mayen. Henry Hudson discovered the island in 1607. It was named for Captain Jan May, who made it a whaling base after 1614. Norway annexed the island in 1929.