Report on Home Reef (Tonga) — August 1984
Scientific Event Alert Network Bulletin, vol. 9, no. 8 (August 1984)
Managing Editor: Lindsay McClelland.
Home Reef (Tonga) Pumice from March-April eruption continues to drift N and W
Please cite this report as:
Global Volcanism Program, 1984. Report on Home Reef (Tonga). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 9:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198408-243080.
18.992°S, 174.775°W; summit elev. -10 m
All times are local (unless otherwise noted)
Large quantities of pumice, probably from the early March eruption of Home Reef, began to arrive about 10 April at Futuna Island (14.42°S, 178.33°W) and Alofi Island (14.45°S, 178.08°W), roughly 700 km NW of Home Reef. ORSTOM geologists collected samples of pumice fragments that were typically 3-4 cm in diameter but occasionally reached 15-20 cm in largest dimension. During fieldwork on Futuna and Alofi islands in July, ORSTOM personnel saw pumice accumulations as much as 30 cm thick on the upper parts of some beaches. People aboard a ship that left Fiji in early May saw pumice as far west as 100 km from Vanuatu about 8 May. Arrival of pumice in Vanuatu was reported in late June. It was apparently found mainly in the central part of the island group in the vicinity of Efate (17.75°S, 168.3°E) and the Shepherds, about 1,800 km WNW of Home Reef. The pumice seemed to move as discontinuous "streamers," but was as much as 0.25 m thick on parts of some beaches.
Geologic Background. 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, copious amounts of floating pumice, and an ephemeral island 500 x 1500 m wide, with cliffs 30-50 m high that enclosed a water-filled crater. Another island-forming eruption in 2006 produced widespread dacitic pumice rafts that reached as far as Australia.
Information Contacts: P. Maillet, J. Eissen, M. Monzier, ORSTOM, New Caledonia; A. Dahl, Noumea, New Caledonia; A. McCutchan, Dept. of Geology, Mines, and Rural Water Supplies, Vanuatu; G. Greene, USGS, Menlo Park CA.