Geologic Background:
A fumarolically active crater, breached to the
SW with a fresh lava flow extending to the sea, is
located on the small, less than 2-km-wide island of
Fonualei. In contrast to other islands of the Tonga arc,
Fonualei lavas are of dacitic composition.
Historic Activity:
- At least 7 eruptions since 1791, with the last in
1974.
- Major eruptions in 1846 and 1847. Lava flows occurred
in both years; in 1846 explosive eruptions produced large
pumice rafts, and the following year ashfall damaged
crops on the island of Vavua, 56 km away and fell on
vessels up to 950 km distant.
- In 1939 explosive and effusive activity occurred from
summit and flank vents, and water spouts were reported
1.6 km SE of the island.
Recent Activity:
Data Sources:
- Smithsonian's SEAN Bulletin (V. 4, No. 7 and 12)
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