Cruise Plan
30 September 2009
The key purpose of this cruise is to search systematically for and locate the first sites of deep-sea hydrothermal activity along the ~110km of the Mid Cayman Spreading Center (17°50'-18°50'N, 81°30'-82°00'W) - Earth's deepest- lying ultraslow spreading ridge.
Leg 1:-
1) We will conduct a systematic survey using vertical CTD-rosette casts at 32 stations, in depths up to 6000m water depth
2) Interspersed with our systematic CTD survey we will also conduct a series of Nereus AUV deployments. Nereus will be used in three separate phases to (I) search systematically through the water column using in situ sensors to prospect for hydrothermal plumes; (II) map the seafloor using the Imagenex sonar; (III) photograph the seafloor using a down-looking digital still camera.
Leg 2:-
1) Assuming we have successfully tracked at least one new hydrothermal field to source, the primary focus of this cruise will be to dive on that site with Nereus in ROV mode to provide first video-documentation and characterization of the site and to conduct first sampling of vent-fluids, microbial and macrobioloical specimens and geological material - mineral deposits and rocks.
2) In addition we will aim to conduct the deepest submersible dive anywhere in the Atlantic (to >6800m) and to collect biological, geological and geochemical samples from the deep seafloor.