Flow in the Endeavour Segment's Rift Valley

Progressive vector diagrams for Acoustic Doppler Current Profiler time series, projected onto across- and along-valley coordinates at (a) the central valley and (b) Easter Island. Stars mark intervals of 1 day. The altitude in meters above the bottom of each record is indicated.  These diagrams indicate pathways of particles if currents have no spatial variability, an unrealistic idealization, but one that is useful in visualizing changes in current magnitude and direction with height above the seafloor .  

From García-Berdeal, et al. (2006).

During the Thermal Grid and LExEn programs (Paul Johnson, Chief Scientist) of 2000-2004, a variety of measurements of currents and water mass properties were made within the lower water column of the axial valley.

Objectives:

• Characterization of the near bottom boundary layer (BBL) of  low-temperature hydrothermal vents, including the vertical turbulent heat flux
• Physics and observations of tidal currents within the axial valley and the resulting variability in high temperature plumes
• The implications of currents and turbulence to larval dispersion and retention.

Investigators

Susan Hautala (University of Washington)
Paul Johnson (University of Washington)
Irene García-Berdeal (University of Washington)
Matt Pruis (NorthWest Research Associates, Redmond)
Tor Bjorklund (University of Washington)
Leif Thomas (Stanford)

Data

Plots and data for measurements of diffuse heat flux and flow in the turbulent benthic boundary layer

Publications

• Hautala, S., H. P. Johnson, M. Pruis, I. Garcia-Berdeal, T. Bjorklund (2012).  Low-temperature hydrothermal plumes in the near-bottom boundary layer at Endeavour Segment, Juan de Fuca Ridge.  Oceanography 25: 192-195
• García-Berdeal, I. (2006). Hydrography and flow in the axial valley of the Endeavour Segment: Implications for larval dispersal. PhD Dissertation, University of Washington, Seattle.
• Garcia Berdeal, I., S. L. Hautala, Leif N. Thomas and H. P. Johnson (2006). Vertical structure of time-dependent currents in a mid-ocean ridge axial valley. Deep-Sea Res. 53: 367-386.
• Pruis, M.J. (2004). Energy and volume flux into the deep ocean: Examining diffuse hydrothermal systems. PhD Dissertation, University of Washington, Seattle.
• Johnson, H. P., S. L. Hautala, M. A. Tivey, C. D. Jones, J. Voight, M. Pruis, I. Garcia-Berdeal, L. A. Gilbert, T. Bjorklund, W. Fredericks, J. Howland and the Thermal Grid Scientific Party (2002). A systematic examination of hydrothermal circulation: Endeavour Segment, Juan de Fuca Ridge. EOS Transactions of the American Geophysical Union 83: 73 and 78. 

Funding

National Science Foundation
University of Washington Royalty Research Fund