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Report on Home Reef (Tonga) — March 1985

Home Reef

Scientific Event Alert Network Bulletin, vol. 10, no. 3 (March 1985)
Managing Editor: Lindsay McClelland.

Home Reef (Tonga) Barnacle-encrusted pumice found on two islands

Please cite this report as:

Global Volcanism Program, 1985. Report on Home Reef (Tonga) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 10:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198503-243080

Home Reef


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

All times are local (unless otherwise noted)

Fragments of pumice were found in early 1985 at three sites in the Solomon Islands. Pumice fragments found near the high water mark were without attached shellfish, but those found lower on the beach were encrusted with barnacles of the genus Lepas that were up to about a cm in length, suggesting that they had been in the water for a few months or more. Since the March 1984 eruption of Home Reef, floating pumice has been found in numerous locations to the SW and NW, as far away as 1,800 km (Efate Island, Vanuatu in late June).

Large quantities of pumice were found by Henry Isa on the SE coast of Alu Island at Aleana village (7.1°S, 155.75°E, about 3450 km WNW of Home Reef). Mr. Isa saw the pumice by 31 January, but its date of arrival was not known. A large amount of pumice was also present at Koela village on the SW coast of Savo Island (9.1°S, 159.8°E, about 2,950 km WNW of Home Reef) when Alison Papabatu visited the island 27 February. Lesser quantities of pumice were found 19 March and collected by Deni Tuni on Savo's SE coast at Kolika village. Residents of the island did not know when the pumice had arrived. No fresh pumice was found along the E side of Savo Island, nor had any been seen at Honiara, Guadalcanal Island, about 30 km SE of Savo.

Further Reference. Rodda, P., 1986, Home Reef Pumice in Fiji (second edition); Mineral Resources Dept. Note BP1/58, 5 pp.

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: Deni Tuni, Ministry of Natural Resources, Solomon Islands.