National Oceanic and
Atmospheric Administration
United States Department of Commerce


FY 2001

Prospecting for hydrothermal vents using moored current and temperature data: Axial Volcano on the Juan de Fuca Ridge, northeast Pacific

Lavelle, J.W., M.A. Wetzler, E.T. Baker, and R.W. Embley

J. Phys. Oceanogr., 31(3), 827–838, doi: 10.1175/1520-0485(2001)031<0827:PFHVUM>2.0.CO;2 (2001)

Tidal and inertial currents and profuse hydrothermal discharge at recently erupted Axial Volcano, Juan de Fuca Ridge, cause relatively large and rapid temperature (T) changes in the near-bottom water column. Measurements show short-term T variations of as much as 0.13°C at 30 m and 0.18°C at 150 m above bottom and currents that have strong tidal components and means of 3-5 cm s−1. Locations and magnitudes of the hydrothermal sources leading to the observed T variations have been inferred via an inverse calculation. Results imply noncongruent source regions around the mooring site for plumes from low- and high-buoyancy flux sources. Water column and seafloor observations in the volcano?s caldera region generally support the distribution of source types and sites inferred. A high-buoyancy flux, ephemeral venting site, unexpected on the eastern shoulder of the volcano, is also indicated by the inverse calculation and supported by water-column survey data. Over the O(10 km2) calculation region, heat flux from low-buoyancy hydrothermal sources is apparently less than heat flux from high-buoyancy hydrothermal sources, a result that is in disagreement with previous reports on the balance of heat flux between vent source types.

Feature Publications | Outstanding Scientific Publications

Contact Sandra Bigley |