9529737 Hey This project will collect high-resolution deep-towed sidescan and bathymetric data to map the detailed pattern of faults, fissures, and recent volcanic eruptive sites along a section of the East Pacific Rise at 30 degrees south. CTD/nephelometer mounted on the vehicle will provide precise hydrothermal plume distributions, and tow-yo surveys will determine two-dimensional anomalies of temperature, particle concentration and the dissolved fraction of certain chemical species. The objective of this project is to understand the structural controls on hydrothermal venting at superfast spreading rates, the temporal controls on venting, and the relative importance of hydrothermal venting and deep ocean currents in forming far-field plumes.