A new type of water and geochemical flux meter will be developed and tested to measure the chemical parameters and flow rates of fluids that seep from the seafloor into the water column. These measurements address a key component of geochemical and hydro-tectonic studies in both convergent and divergent margins on the seafloor. Accurate determination of the magnitudes and spatial distribution of flux rates of fluid/geochemical components in the system are critical to these geophysical process studies. Instrumentation will be designed to quantify output fluxes (i.e., diffusive and focused) by collecting fluid samples and measuring Darcy fluid velocities through the sediment surface on the order of 0.1 to 100 mm y-1, allowing direct measurements to be attempted for the first time at low flux-rate vents and regions of slow diffuse flow. Funds are also provided to replace several NSF-sponsored instruments that were recently lost at sea during an NSF-funded expedition. Scripps Institution of Oceanography is providing $165,000 in cost sharing, which represents 30% of the total project's cost.
