Abstract
An expedition to the Kavachi submarine volcano (Solomon Islands) in January 2015 was serendipitously timed with a rare lull in volcanic activity that permitted access to the inside of Kavachi’s active crater and its flanks. The isolated location of Kavachi and its explosive behavior normally restrict scientific access to the volcano’s summit, limiting previous observational efforts to surface imagery and peripheral water-column data. This article presents medium-resolution bathymetry of the main peak along with benthic imagery, biological observations of multiple trophic levels living inside the active crater, petrological and geochemical analysis of samples from the crater rim, measurements of water temperature and gas flux over the summit, and descriptions of the hydrothermal plume structure. A second peak was identified to the southwest of the main summit and displayed evidence of diffuse-flow venting. Microbial samples collected from the summit indicate chemosynthetic populations dominated by sulfur-reducing e-proteobacteria. Populations of gelatinous animals, small fish, and sharks were observed inside the active crater, raising new questions about the ecology of active submarine volcanoes and the extreme environments in which large marine animals can exist.
Highlights
The New Georgia Island Group is the result of a complex tectonic configuration, characterized by subduction of the active Woodlark Spreading Center (WSC) beneath the Solomon Islands intra-oceanic arc
We report here on our initial results, which include evidence of diffuse-flow venting on a confirmed second peak, a megafaunal community living inside the active crater, and insights into the eruptive processes and magma source characteristics of Kavachi’s active volcanism
Hydrothermal Plumes Opportunities to sample hydrothermal plumes associated with actively erupting submarine volcanoes are often limited by safety concerns
Summary
The New Georgia Island Group is the result of a complex tectonic configuration, characterized by subduction of the active Woodlark Spreading Center (WSC) beneath the Solomon Islands intra-oceanic arc. This triple junction is the site of active volcanism, crustal uplift that closely matches subducted bathymetric features from the WSC, and a proposed “slab window” that leaves asthenospheric mantle in direct contact with a thin overlying crust By far the most active volcano in the region, Kavachi is known for frequent phreatomagmatic (denoting explosive water-magma interaction) and subaerial eruptions leading to occasional ephemeral island emergence (Johnson and Tuni, 1987). The remote geographic location and inherent danger of frequent eruptions has prevented scientists from observing the proximal area of Kavachi’s summit crater
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
