Report on Kavachi (Solomon Islands) — May 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 5 (May 1991)
Managing Editor: Lindsay McClelland.
Kavachi (Solomon Islands) Continued explosions from new island
Please cite this report as:
Global Volcanism Program, 1991. Report on Kavachi (Solomon Islands). In: McClelland, L. (ed.), Bulletin of the Global Volcanism Network, 16:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199105-255060.
8.991°S, 157.979°E; summit elev. -20 m
All times are local (unless otherwise noted)
Pilots from Solomon Islands Airways reported that "the volcano is still active and increasing in size, though slowly" as of 14 June. Photographs taken on 12 May (by Rod Marsland, a Rabaul-based pilot) show the island to have been ~110 m in diameter, with a 15-m-diameter crater (assuming a height of 25 m based on an average of several visual estimates). Lava was being ejected to 30 m height in the photos. The new island's exact location remains uncertain.
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: P. de Saint-Ours, RVO.