UW Oceanography Mid-Ocean Ridge Processes: Research Projects

Thermal output of a hydrothermal system: water column studies

The hot fluid discharged from hydrothermal vents on the seafloor rises as a plume in the deep ocean. This project involves use of the submersible ALVIN to characterize the time and space scales associated with entrainment of local seawater into this rising plume and the accompanying chemical and biochemical reactions. Funded by the National Science Foundation. Investigator Russ McDuff, Collaborators: NOAA PMEL: John Lupton, Richard Feely, Gary Massoth; UC Santa Barbara: Libe Washburn

Sulfide flanges: geological, chemical and biological energetics of exposed, active hydrothermal systems

Flanges are overhanging ledges projecting from large constructional sulfide edifices which trap ponds of buoyant high temperature fluid. The flange environment represents a microcosm of a hyrothermal system, one which can be well-instrumented to study the flow of energy into the associated biological community. Funded by the National Science Foundation. Investigators John Delaney, Russ McDuff, Marv Lilley

Use of the Jason/Medea-Sea Cliff-Laney Chouest system to study crustal accretionary processes

The Jason remotely operated vehicle is a new and flexible technology for studying the seafloor. This initial science program had the goal of evaluating the use of this new tool in a well studied area on the Endeavour Segment of the Juan de Fuca Ridge. Funded by the Office of Naval Research. Some imagery from the program is available on the DSL server at WHOI, operators of the Jason ROV. Investigators: John Delaney, J.-C. Sempere, Russ McDuff.

Are upflow zones boundaries between adjacent hydrothermal systems? Geological and geochemical tests

Spatial variability in vent fluid chemistry has been interpreted by ourselves and others as a result of a complex series of processes related to phase separation and segregation within the oceanic crust. This program examines an alternative hypothesis, that the spatial patterns seen are related to the mixing of fluids associated with two adjacent, independent hydrothermal convection cells. Funded by the National Science Foundation. Investigators: John Delaney, Russ McDuff , Marv Lilley. Collaborators: NOAA PMEL: Dave Butterfield, John Lupton. Project Web.

Physical, chemical and biological consequences of diking/eruptive events at spreading centers

Studies over the past decade suggest that the "quantum" event of ocean crustal construction is a the injection of a dike. This perturbation, marked by seismic activity, may change the intensity of existing hydrothermal circulation or even initiate new activity. This project couples a modelling study of these effects with continuing field work at the site of a recent diking event, the CoAxial event of 1993. More information is available on the Coaxial Home Page maintained by NOAA's PMEL. Funded by the National Science Foundation. Investigators: John Delaney, John Baross, Russ McDuff, Marv Lilley, Will Wilcock. Collaborators: University of Arizona: Denis Norton.

Precise measurement of the heat flux from a hydrothermal vent system

The very essence of a hydrothermal system is transfer of heat by a convecting fluid. Despite this central role played by heat transfer, we have a woefully poor knowledge of the flux of heat from seafloor hydrothermal systems and its variation through time. This lack of knowledge is not from a lack of trying. Many different investigators have made estimates of the flux of heat from seafloor hydrothermal systems. The Endeavour Segment of the Juan de Fuca Ridge is perhaps the best- studied example. There are issues of what style(s) of venting are included in the estimates, the errors inherent in the measurements, sampling statistics, and the spatial and temporal averaging that is associated with each of the individual approaches. Thus while the reported values are of a reasonable order of magnitude the resulting estimates vary widely (from ~100 to ~10000 MW), have large uncertainties (often spanning an order of magnitude), and do not allow us to address very fundamental questions, for example, is the flux of heat steady or varying through time? We propose to take advantage of technological advances in deep sea autonomous vehicles to make precise measurements, achieving uncertainty better than 20%, of the heat flux from the Main Endeavour Field (MEF) examining its variation across a range of time scales. Funded by the National Science Foundation Investigators: Russ McDuff, Fritz Stahr, Dana Yoerger, and Al Bradley. Project Web..

Fluxes of Heat and Salt from Endeavour Segment Vent Fields: Discrete Measurements as a Test of the Sea Breeze "Flux Meter" Hypothesis

Entrainment into rising hydrothermal plumes in the axial valley of the central portion of the Endeavour Segment is of a magnitude that should give rise to measurable convergence of flow of ocean water into the valley. This project examines whether measurements of this flow can serve as a proxy measure of the fluid discharge from venting sources by comparing flux measurements from individual fields to the horizontal fluid transport within the confines of the valley walls. Investigators: University of Washington: Russ McDuff (UW); Woods Hole Oceanographic Institution: Dana Yoerger, and Al Bradley; Institute of Ocean Sciences, Fisheries and Oceans Canada: Rick Thomson. Supported by NSF Grant OCE-0242736 and Fisheries and Oceans Canada. Project Web.

Image Correlation Velocimetry

Image correlation velocimetry or ICV involves the tracking of visible features in a flow. Specifically the patterns associated with the largest scales of turbulence undergo displacement, rotation and deformation and these can be quantified by analysis of a sequence of images closely spaced in time. We are working with the Center for In Situ Exploration and Sample Return at JPL to apply their engineering expertiese in digital imaging, embedded systems, and algorithms for processing and data compression to develop a prototype in situ ICV instrument for use at hydrothermal vents. Collaborators: University of Washington: Russ McDuff, Tim Crone, William Wilcock; Jet Propulsion Laboratory: Greg Bearman, Lloyd French and Gindi French.
Update 2/7/03 RMcD/mcduff@ocean.washington.edu