Report on Additional Reports (Unknown) — November 1990
Bulletin of the Global Volcanism Network, vol. 15, no. 11 (November 1990)
Managing Editor: Lindsay McClelland.
Additional Reports (Unknown) Fiji: Details of aerial pumice observations; pumice washes ashore on one island
Please cite this report as:
Global Volcanism Program, 1990. Report on Additional Reports (Unknown) (McClelland, L., ed.). Bulletin of the Global Volcanism Network, 15:11. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199011-600500
Lat Unknown, Unknown; summit elev. m
All times are local (unless otherwise noted)
The following, from Trevor Jones and Peter Rodda, supplements preliminary reports of pumice sightings near Fiji in 15:10.
"A report of floating pumice was received from Nitin Hiralal, First Officer of Air Pacific flight FJ 914 (Nadi-Sydney) on 16 October. At 1058, he saw a 'pumice swirl' ~15-30 km across, at 19.10°S, 175.41°E, from an altitude of ~10 km. It had a regular circular shape. He saw nothing else, but presumed that there had to be some local volcanological activity because of the regular pattern. He says that it is 'reasonably common' to see streaks of pumice along wave crests on the Vanuatu and Tonga routes (from Fiji). On 17 October, while returning to Fiji, he checked and saw 'only pumice streaks' at about 1330, presumably around the same position. Pumice was also reported 150 km S of Nadi [roughly 19.1°S, 177.5°E] from an Auckland-Nadi flight on 16 October. There have been no reports from ships of pumice in the area, nor have any reports other than the above appeared in the Fiji Times.
"The relative compactness of the first presumed pumice reported suggests an origin in the area, but although submarine volcanoes exist in the vicinity, no peaks are known to rise above ~1,800 m depth in the general area, and it seems unlikely that pumice could form. The two locations from which presumed pumice was reported suggest an origin on the Tonga-Kermadec Ridge, roughly in the latitude of Fonua Fo'ou [20.3°S] or farther S; based on the drift time of Home Reef pumice in 1964, from the first report of the eruption to the first arrival in Fiji and later arrival in Suva, pumice could reach the site in the North Fiji Basin from that part of the Tonga Ridge in ~75-85 days, giving a possible eruption date in late July (or earlier if farther S - if Monowai Seamount, ~95-105 days, or early to mid-July).
"Four reply-paid telegrams sent in late October to the agents at four Postal Agencies in S Fiji brought no replies. The radio-telephone to Vunisea, Post Office for Kadavu Province [about 19°S, 178.5°E] is out of order, so no information about the arrival of pumice there can conveniently be obtained quickly. Questionnaires have been posted." By mid-November, pumice had been reported from Koro Island (about 17.3°S, 179.4°E), and questionnaires were being sent to locations throughout the Lau Group (E of Fiji's largest islands) and elsewhere.
Geological Summary. Reports of floating pumice from an unknown source, hydroacoustic signals, or possible eruption plumes seen in satellite imagery.
Information Contacts: T. Jones and P. Rodda, Mineral Resources Dept, Suva, Fiji.