Collaborative proposal: Integrated Hydrothermal and Petrological Studies of the Eastern Lau Spreading Center

The Eastern Lau Spreading Center in the Lau Basin has been chosen an an integrated studies site by the Ridge 2000 program to understand a back-arc spreading center from mantle to microbe. This spreading center has a continuous gradient in the subduction influence that is characteristic of back-arc basin basalts, and the spreading rate changes by nearly a factor of two. Hydrothermal discovery is the driving force behind the logistic plan of this project. Two previous cruises to the spreading center will provide bathymetry and side-scan data. This project will use the ROV ABE to survey six target regions for water column properties at depths that traverse the neutrally buoyant plume. ABE dives at a height above bottom of 50m will obtain high-resolution bathymetry as well as water column measurements. ABE dives at a height of 5-10m will then provide complete photo coverage of the discovered vent sites.