Osmotic Fluid Sampler

Long term measurements of fluid chemistry are critical to understanding hydrothermal and methane seep environments because this impacts reactions in hydrothermal chimneys and in seep sediments and the associated biota that thrive inside and outside of the active black smokers, in the subseafloor, and where methane is seeping from the seafloor in margin environments.

To meet this need, the Regional Cabled Array uses uncabled osmotic samplers that draw in hydrothermal fluids and methane seep-derived fluids into small capillary-like tubing for periods of one year. These instruments, now installed in diffuse flow site coupled to the 3D thermistor array near the Mushroom black smoker chimney and near Einsteins' Grotto at Southern Hydrate Ridge, are recovered annually by the ROV. Onboard, small ~ 1 m length sections of the tubing are cut and the fluids removed for shore-based chemical analyses.