HR: 16:45h
AN: V44A-05    [Abstracts]
TI: Vailulu'u Seamount, Samoa: Life and Death at the Edge of An Active Submarine Volcano
AU: * Vailulu'u Research Group, T
EM: hstaudigel@ucsd.edu
AF: Scripps Institution of Oceanography, University of California Mailcode 0225, La Jolla, CA 92117 United States
AB: Exploration of Vailulu'u seamount (14°13'S; 169°04'W) by manned submersible, ROV, and surface ship revealed a new, 300m tall volcano that has grown in the summit crater in less than four years. This shows that Vailulu'u's eruption behavior is at this stage not predictable and continued growth could allow Vailulu'u to breach sea level within decades Several types of hydrothermal vents fill Vailulu'u crater with particulates that reduce visibility to less than a few meters in some regions. Hydrothermal solutions mix with seawater that enters the crater from its breaches to produce distinct biological habitats. Low temperature hydrothermal vents can produce Fe-oxide chimneys or up to one meter-thick microbial mats. Higher temperature vents (85°C) produce low salinity acidic fluids containing buoyant droplets of immiscible CO2. Low temperature hydrothermal vents at Nafanua summit (708m depth) support a thriving population of eels (Dysommia rusosa). The areas around the high temperature vents and the moat and remaining crater around the new volcano is almost devoid of any macroscopic life and is littered with fish, and mollusk carcasses that apparently died from exposure to hydrothermal fluid components in deeper crater waters. Acid- tolerant polychaetes adapt to this environment and feed near and on these carcasses. Vailulu'u presents a natural laboratory for the study of how seamounts and their volcanic systems interact with the hydrosphere to produce distinct biological habitats, and how marine life can adapt to these conditions or be trapped in a toxic volcanic system that leads to mass mortality. The Vailulu'u research team: Hubert Staudigel, Samantha Allen, Brad Bailey, Ed Baker, Sandra Brooke, Ryan Delaney, Blake English, Lisa Haucke, Stan Hart, John Helly, Ian Hudson, Matt Jackson, Daniel Jones, Alison Koleszar, Anthony Koppers, Jasper Konter, Laurent Montesi, Adele Pile, Ray Lee, Scott Mcbride, Julie Rumrill, Daniel Staudigel, Brad Tebo, Alexis Templeton, Rhea Workman, Craig Young, Robert Zierenberg.
UR: http://earthref.org/ERESE/projects/ALIA/
DE: 0400 BIOGEOSCIENCES
DE: 0448 Geomicrobiology
DE: 3017 Hydrothermal systems (0450, 1034, 3616, 4832, 8135, 8424)
DE: 3037 Oceanic hotspots and intraplate volcanism
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005