Surtsey, volcanic island, c.1.25 sq mi (3.2 sq km), S of Iceland in Vestmannaeyjar (Westman Islands). The island was formed by the eruption (Nov., 1963) of Sutur, an underwater volcano named for a giant of Icelandic legend. For four months the fissure, estimated to be c.1,500 ft (460 m) long, emitted explosions of ash, cinders, and pumice in a column rising more than 1,000 ft (305 m). Lava flows beginning in Apr., 1964, formed a shell that helped assure the continuing existence of the island. The eruptions ended in 1967. Scientists were able to study the formation of tornadoes, waterspouts, hail, and lightning—all manifestations of the volcano itself—as well as the first evidence of life on the new island. Surtsey was designated a nature reserve in 1965.