Report on Teahitia (France) — April 1984
Scientific Event Alert Network Bulletin, vol. 9, no. 4 (April 1984)
Managing Editor: Lindsay McClelland.
Teahitia (France) Seismic swarms indicate two submarine eruptions
Please cite this report as:
Global Volcanism Program, 1984. Report on Teahitia (France) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 9:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198404-333010
17.564°S, 148.821°W; summit elev. -1743 m
All times are local (unless otherwise noted)
From August 1983 to March 1984, the RSP recorded numerous sequences of low-frequency volcanic tremor and two seismic swarms associated with submarine eruptions at Teahitia. On 20-21 December, 300 very small earthquakes were recorded. From 3 March-15 April 1984, approximately 9,000 earthquakes were recorded, accompanied by low- and high-frequency spasmodic and harmonic tremor (figure 3).
Geological Summary. Teahitia is a submarine volcano in the Society Islands whose summit reaches to within ~1700 m of the surface, 40 km NE of the SE tip of Tahiti Island. Several seismic swarms in the 1980s included volcanic tremor that may have resulted from submarine eruptions (Talandier and Opal, 1984). Rocks dredged in 1986 "exploded" when they reached the surface, suggesting recent lava extrusion that had not yet had time to equilibrate with pressure and temperature conditions on the submerged flanks of the edifice. Two hydrothermal fields each about 1 km by 400 m in size that emitted low-temperature hydrothermal venting were discovered on the flanks during submersible dives in 1986 and 1989.
Information Contacts: J.M. Talandier, Lab. de Géophysique, Tahiti.