Exploring the “Sharkcano”: Biogeochemical observations of the Kavachi submarine volcano (Solomon Islands) using simple, cost-effective methods.

Wednesday, 16 December 2015
Poster Hall (Moscone South)
Brennan Theodore Phillips1, Simon Albert2, Steven Carey3, Alex DeCiccio1, Matthew Dunbabin4, Ashton F Flinders5, Alistair Robert Grinham2, Brad Henning6, Corey Howell7 and Scientific Team of Kavachi 2015, (1)University of Rhode Island Narragansett Bay, Graduate School of Oceanography, Narragansett, RI, United States, (2)University of Queensland, Brisbane, Australia, (3)University of Rhode Island Narragansett Bay, Narragansett, RI, United States, (4)Queensland University of Technology, Wynnum West, Australia, (5)University of Rhode Island, Kingston, RI, United States, (6)National Geographic Society, Remote Imaging Team, Washington, DC, United States, (7)The Wilderness Lodge, Gatokae Island, Solomon Islands
Kavachi is a highly active undersea volcano located in the Western Province of the Solomon Islands, known for its frequent phreatomagmatic eruptions and ephemeral island-forming activity. The remote location of Kavachi and its explosive behavior has restricted scientific exploration of the volcano, limiting observations to surface imagery and peripheral water-column data. An expedition to Kavachi in January 2015 was timed with a rare lull in volcanic activity, allowing for observation of the inside of Kavachi’s caldera and its flanks. Here we present medium-resolution bathymetry of the main peak paired with benthic imagery, petrologic analysis of samples from the caldera rim, measurements of gas flux over the main peak, and hydrothermal plume structure data. A second peak was discovered to the Southwest of the main cone and displayed evidence of diffuse-flow venting. Populations of gelatinous animals, small fish, and sharks were observed inside the active crater, raising new questions about the ecology of active submarine volcanoes. Most equipment used in this study was lightweight, relatively low-cost, and deployed using small boats; these methods may offer developing nations an economic means to explore deep-sea environments within their own territorial waters.