Report on Kavachi (Solomon Islands) — February 1981
Scientific Event Alert Network Bulletin, vol. 6, no. 2 (February 1981)
Managing Editor: Lindsay McClelland.
Kavachi (Solomon Islands) More submarine activity
Please cite this report as:
Global Volcanism Program, 1981. Report on Kavachi (Solomon Islands). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 6:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198102-255060.
8.991°S, 157.979°E; summit elev. -20 m
All times are local (unless otherwise noted)
On 11 November at 1215 a Solair flight diverged from its normal route to observe the volcano. Drs. Hughes and Dunkley of the Geological Division, Ministry of Natural Resources, reported that a dense, nearly vertical steam jet was billowing to approximately 300 m, but dissipated as the plane approached. The eruption site was marked by white water, and a stream of muddy, turbid, pale brown water extending several km NE from the volcano. On 3 December Dunkley observed an area of discolored water several hundred meters wide extending NW (down current) about 4 km. No eruption was in progress.
Geologic Background. Named for a sea-god of the Gatokae and Vangunu peoples, Kavachi is one of the most active submarine volcanoes in the SW Pacific, located in the Solomon Islands south of Vangunu Island about 30 km N of the site of subduction of the Indo-Australian plate beneath the Pacific plate. Sometimes referred to as Rejo te Kvachi ("Kavachi's Oven"), this shallow submarine basaltic-to-andesitic volcano has produced ephemeral islands up to 1 km long many times since its first recorded eruption during 1939. Residents of the nearby islands of Vanguna and Nggatokae (Gatokae) reported "fire on the water" prior to 1939, a possible reference to earlier eruptions. The roughly conical edifice rises from water depths of 1.1-1.2 km on the north and greater depths to the SE. Frequent shallow submarine and occasional subaerial eruptions produce phreatomagmatic explosions that eject steam, ash, and incandescent bombs. On a number of occasions lava flows were observed on the ephemeral islands.
Information Contacts: D. Tuni, Ministry of Natural Resources, Honiara.