Open AccessLocating hydrothermal vents by detecting buoyant, advected plumes
Author(s) -
Veirs Scott R.,
McDuff Russell E.,
Lilley Marvin D.,
Delaney John R.
Publication year - 1999
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jb900291
Subject(s) - hydrothermal circulation , plume , geology , hydrothermal vent , ridge , panache , mid ocean ridge , current (fluid) , instability , geophysics , petrology , mechanics , oceanography , seismology , meteorology , paleontology , physics
An improved method of detecting buoyant hydrothermal plumes and locating their source vents is introduced. Plumes are detected by computing fluid stability from conductivity, temperature, and depth measurements acquired during navigated, towed, vertically oscillating casts over the Endeavour Segment of the Juan de Fuca Ridge. For each instability detected, the maximum range to its hydrothermal source is estimated by multiplying a theoretical plume equilibration time by a measured current velocity. Using an estimate of current direction, the method reliably locates plume sources where they are known to exist: in all of the focused vent fields mapped by submersible and in several isolated, diffuse flow sites. The method generates a distribution of hydrothermal sources that is more consistent with variations in surface permeability than with circulation cells spaced evenly along a uniformly permeable axis. Axial instabilities are nearly continuous along the heavily fissured and fractured western wall of the axial valley. Beyond the axial valley, instabilities evidence that hydrothermal upflow penetrates the outer slopes of the ridge crest, probably along a boundary between sheet and pillow flows.