Transport in the Axial Valley:

Effect of Current Variability on Temperatures Measured in a Non-buoyant Hydrothermal Plume (Abstract)

Problem Description:
Heat fluxes are not easily measured at hydrothermal vent sources. Instead heat flux estimates for vents or vent fields are usually inferred from measurements of temperature anomalies (delta_theta) and currents in neutrally buoyant plumes. Those estimates require integrating values for delta_theta and currents over a flux plane. One source of inaccuracy stems from constantly changing water flow. Variable currents cause heat from vents to pool over the vents at times and to stream in narrow plumes away from the vents at others. Directional variability of currents can bring the plume directly to the sensor in one instance or cause the plume to be poorly sampled in the next. In this study measurements and a model plume are used together to examine the inaccuracy of heat-flux estimates caused just by variable currents.

The combined effluent from the hydrothermal sources Foutain, Monolith, Cavern and Pipe Organ form to create the buoyant plume found at North Cleft. Individual plume identities are blurred as the currents mix them together. click for larger view FLI Animation (7.8 Mb) mov Animation (5.9 Mb)

Wetzler, M.A., J.W. Lavelle, G.A. Cannon, and E.T. Baker (1998): Variability of temperature and currents measured near Pipe Organ hydrothermal vent site. Mar. Geophys. Res., 20, 505-516.

Related Papers:

Lavelle, J.W., M.A. Wetzler, E.T. Baker, and R.W. Embley (2001): Prospecting for hydrothermal vents using moored current and temperature data: Axial Volcano on the Juan de Fuca Ridge, northeast Pacific. J. Phys. Oceanogr., 31, 827-838. [PDF]

Buoyant plumes in cross flows

Lavelle, J.W. (1997): Buoyancy-driven plumes in rotating, stratified cross flows: Plume dependence on rotation, turbulent mixing, and cross-flow strength. Journal of Geophysical Research, 102(C2), 3405-3420.

Geochemical Transport

Lavelle, J.W., J.P. Cowen, and G.J. Massoth (1992): A model for the deposition of hydrothermal manganese near ridge crests. Journal of Geophysical Research, 97(C5), 7413-7427.

Feely, R.A., M. Lewison, G.J. Massoth, G. Robert-Baldo, J.W. Lavelle, R.H. Byrne, K.L. Von Damm, and H.C. Curl, Jr. (1987): Composition and dissolution of black smoker particulates from active vents on the Juan de Fuca Ridge. Journal of Geophysical Research, 92(B11), 11,347-11,363.