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Report on Home Reef (Tonga) — December 2008

Home Reef

Bulletin of the Global Volcanism Network, vol. 33, no. 12 (December 2008)
Managing Editor: Richard Wunderman.

Home Reef (Tonga) Top of seamount 10 m below sea level; hydrothermal activity

Please cite this report as:

Global Volcanism Program, 2008. Report on Home Reef (Tonga) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 33:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200812-243080

Home Reef


18.992°S, 174.775°W; summit elev. -10 m

All times are local (unless otherwise noted)

Until November 2008 no observations of the Home Reef island had been reported since a visit by Scott Bryan and colleagues in mid-February 2007 (BGVN 32:04), when a small pumice mound less than 5 m above sea level was present at low tide. The island had been constructed during an explosive eruption in August 2006 (BGVN 31:09, 31:10, and 31:12). When Bryan returned on 20 November 2008 the island was no longer present.

The summit of the volcano on 20 November was 9-10 m below sea level, forming a relatively smooth-topped summit region approximately 500 x 500 m in area. The top of the summit was located at 18°59.421' S, 174°46.138' W (18.990°S, 17.769°W). The position of the summit are could be detected by a slight "lipping" of the oceanic swell across the top of the seamount, but the area was also obvious due to continued hydrothermal plume activity producing turbid turquoise water. The hydrothermal plume was displaced to the west of the summit area by ocean currents, and the surface area of discolored water was ~1-2 km2. A discharge of H2S associated with the hydrothermal activity was more subdued than in February 2007.

Geological Summary. Home Reef, a submarine volcano midway between Metis Shoal and Late Island in the central Tonga islands, was first reported active in the mid-19th century, when an ephemeral island formed. An eruption in 1984 produced a 12-km-high eruption plume, large amounts of floating pumice, and an ephemeral 500 x 1,500 m island, with cliffs 30-50 m high that enclosed a water-filled crater. In 2006 an island-forming eruption produced widespread dacitic pumice rafts that drifted as far as Australia. Another island was built during a September-October 2022 eruption.

Information Contacts: Scott Bryan, Centre for Earth and Environmental Science Research, Kingston University London, Kingston Upon Thames, Surrey KT1 2EL, London, United Kingdom; Allan Bowe, Mounu Island Resort, PO Box 7, Neiafu, Vava'u, Tonga.