Report on Kavachi (Solomon Islands) — 19 November-25 November 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 19 November-25 November 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Kavachi (Solomon Islands). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 19 November-25 November 2003. Smithsonian Institution and US Geological Survey.
8.991°S, 157.979°E; summit elev. -20 m
All times are local (unless otherwise noted)
An observer from The Wilderness Lodge reported that a 15-m-high island formed at Kavachi during an eruptive cycle 3 months prior to a visit on 16 November. By 16 November the summit had reduced to ~32 m below sea level. No evidence of volcanic activity was observed during the 3 previous months, which is the first time this has occurred in 4 years of observation.
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.
Source: The Wilderness Lodge