Report on Kavachi (Solomon Islands) — October 1980
Scientific Event Alert Network Bulletin, vol. 5, no. 10 (October 1980)
Managing Editor: David Squires.
Kavachi (Solomon Islands) Small submarine eruption
Please cite this report as:
Global Volcanism Program, 1980. Report on Kavachi (Solomon Islands) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 5:10. Smithsonian Institution.
8.991°S, 157.979°E; summit elev. -20 m
All times are local (unless otherwise noted)
Bruce Kirkwood observed a small submarine eruption on 7 October. A mixture of water, steam, and blocks rose intermittently to more than 100 m above the ocean surface. Sea water surrounding the eruption site was slightly discolored.
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; B. Kirkwood, Solair.