Report on Kavachi (Solomon Islands) — July 1977
Natural Science Event Bulletin, vol. 2, no. 7 (July 1977)
Managing Editor: David Squires.
Kavachi (Solomon Islands) Renewed activity
Please cite this report as:
Global Volcanism Program, 1977. Report on Kavachi (Solomon Islands). In: Squires, D (ed.), Natural Science Event Bulletin, 2:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197707-255060.
8.991°S, 157.979°E; summit elev. -20 m
All times are local (unless otherwise noted)
Renewed activity was first observed on 19 July at 1000 by Solair Pilot Bruce Kirkwood, 3 days after the previous overflight. Eruptions were seen on 20 July, and at about 30-second intervals on 22 July. Ash was ejected by the vent, which remained below the ocean surface.
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: R. Thompson, Geological Survey, Honiara.