A Fiji Air passenger saw two narrow, elongate rafts of drifting pumice in the Kadavu passage ~30 km SE of Suva (figure 1) on 24 January. Fiji's Maritime Surveillance Centre issued a warning to mariners, published in newspapers on 27 January. Pumice was subsequently reported from ships roughly 50 km SW and 160 km NW of the initial observation.

Figure 1. Map of Fiji, from Baleivanualala, 1992, showing locations of pumice rafts seen in early 1992.

A search of the Suva Harbour area on 27 January revealed pumice floating in the Suva Passage and stranded at the high-tide line around the Suva Peninsula. The pumice was gravel-sized, with the largest fragment ~4 cm across. The samples were weathered and some included living barnacles up to 9 mm long. After the 1984 Home Reef (Tonga) eruption, barnacles 1.5 cm long were found on pumice that was at most 25 weeks old, so a provisional maximum age of 15 weeks was assigned by Baleivanualala to the barnacles found in January 1992. Given an estimated drift rate of ~12 km/day (Rodda and Jones, 1990), the pumice might have traveled 1,300 km from the eruption site. No reports of eruptions in the Tonga-Kermadec region have been received.

References. Baleivanualala, V., 1992, Drift pumice in Kadavu Passage, January 1992: Fiji Mineral Resources Department Note BP57/1, 3 pp.

Rodda, P., and Jones, T.D., 1990, The 1990 reports of drift pumice in Fiji (Corrigendum): Fiji Mineral Resources Department Note BP1/91.

Geological Summary. Reports of floating pumice from an unknown source, hydroacoustic signals, or possible eruption plumes seen in satellite imagery.

Information Contacts: V. Baleivanualala and P. Rodda, Mineral Resources Dept, Suva, Fiji.